Index for schemadoc

Dumped on 2004-11-10

# Index of database - schemadoc

- schemadoc

- sl_config_lock
- sl_confirm
- sl_event
- sl_listen
- sl_log_1
- sl_log_2
- sl_node
- sl_path
- sl_seqlastvalue
- sl_seqlog
- sl_sequence
- sl_set
- sl_setsync
- sl_subscribe
- sl_table
- sl_trigger
- altertableforreplication( integer )
- altertablerestore( integer )
- cleanupevent( )
- cleanuplistener( )
- createevent( name, text )
- createevent( name, text, text )
- createevent( name, text, text, text )
- createevent( name, text, text, text, text )
- createevent( name, text, text, text, text, text )
- createevent( name, text, text, text, text, text, text )
- createevent( name, text, text, text, text, text, text, text )
- createevent( name, text, text, text, text, text, text, text, text )
- createevent( name, text, text, text, text, text, text, text, text, text )
- ddlscript( integer, text, integer )
- ddlscript_int( integer, text, integer )
- denyaccess( )
- determineattkindserial( text )
- determineattkindunique( text, name )
- determineidxnameserial( text )
- determineidxnameunique( text, name )
- disablenode( integer )
- disablenode_int( integer )
- droplisten( integer, integer, integer )
- droplisten_int( integer, integer, integer )
- dropnode( integer )
- dropnode_int( integer )
- droppath( integer, integer )
- droppath_int( integer, integer )
- dropset( integer )
- dropset_int( integer )
- droptrigger( integer, name )
- droptrigger_int( integer, name )
- enablenode( integer )
- enablenode_int( integer )
- enablesubscription( integer, integer, integer )
- enablesubscription_int( integer, integer, integer )
- failednode( integer, integer )
- failednode2( integer, integer, integer, bigint, bigint )
- failoverset_int( integer, integer, integer )
- forwardconfirm( integer, integer, bigint, timestamp without time zone )
- getlocalnodeid( name )
- getmoduleversion( )
- getsessionrole( name )
- initializelocalnode( integer, text )
- lockedset( )
- lockset( integer )
- logtrigger( )
- mergeset( integer, integer )
- mergeset_int( integer, integer )
- moveset( integer, integer )
- moveset_int( integer, integer, integer )
- rebuildlistenentries( )
- sequencelastvalue( text )
- sequencesetvalue( integer, integer, bigint, bigint )
- setaddsequence( integer, integer, text, text )
- setaddsequence_int( integer, integer, text, text )
- setaddtable( integer, integer, text, name, text )
- setaddtable_int( integer, integer, text, name, text )
- setdropsequence( integer )
- setdropsequence_int( integer )
- setdroptable( integer )
- setdroptable_int( integer )
- setmovesequence( integer, integer )
- setmovesequence_int( integer, integer )
- setmovetable( integer, integer )
- setmovetable_int( integer, integer )
- setsessionrole( name, text )
- slonyversion( )
- slonyversionmajor( )
- slonyversionminor( )
- slonyversionpatchlevel( )
- storelisten( integer, integer, integer )
- storelisten_int( integer, integer, integer )
- storenode( integer, text )
- storenode_int( integer, text )
- storepath( integer, integer, text, integer )
- storepath_int( integer, integer, text, integer )
- storeset( integer, text )
- storeset_int( integer, integer, text )
- storetrigger( integer, name )
- storetrigger_int( integer, name )
- subscribeset( integer, integer, integer, boolean )
- subscribeset_int( integer, integer, integer, boolean )
- tableaddkey( text )
- tabledropkey( integer )
- tablehasserialkey( text )
- terminatenodeconnections( name )
- uninstallnode( )
- unlockset( integer )
- unsubscribeset( integer, integer )
- unsubscribeset_int( integer, integer )

## Table: sl_config_lock

This table exists solely to prevent overlapping execution of configuration change procedures and the resulting possible deadlocks.

sl_config_lock Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| dummy | integer |

Index - Schema schemadoc

## Table: sl_confirm

Holds confirmation of replication events. After a period of time, Slony removes old confirmed events from both this table and the sl_event table.

sl_confirm Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| con_origin | integer | The ID # (from sl_node.no_id) of the source node for this event
| con_received | integer |
| con_seqno | bigint | The ID # for the event
| con_timestamp | timestamp without time zone | DEFAULT (timeofday())::timestamp without time zone When this event was confirmed

Index - Schema schemadoc

## Table: sl_event

Holds information about replication events. After a period of time, Slony removes old confirmed events from both this table and the sl_confirm table.

sl_event Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| ev_origin | integer | PRIMARY KEY The ID # (from sl_node.no_id) of the source node for this event
| ev_seqno | bigint | PRIMARY KEY The ID # for the event
| ev_timestamp | timestamp without time zone | When this event record was created
| ev_minxid | schemadoc.xxid | Earliest XID on provider node for this event
| ev_maxxid | schemadoc.xxid | Latest XID on provider node for this event
| ev_xip | text | List of XIDs, in order, that are part of this event
| ev_type | text | The type of event this record is for. SYNC = Synchronise STORE_NODE = ENABLE_NODE = DROP_NODE = STORE_PATH = DROP_PATH = STORE_LISTEN = DROP_LISTEN = STORE_SET = DROP_SET = MERGE_SET = SET_ADD_TABLE = SET_ADD_SEQUENCE = STORE_TRIGGER = DROP_TRIGGER = MOVE_SET = SET_DROP_TABLE = SET_DROP_SEQUENCE = SET_MOVE_TABLE = SET_MOVE_SEQUENCE = FAILOVER_SET = SUBSCRIBE_SET = ENABLE_SUBSCRIPTION = UNSUBSCRIBE_SET = DDL_SCRIPT = ADJUST_SEQ =
| ev_data1 | text | Data field containing an argument needed to process the event
| ev_data2 | text | Data field containing an argument needed to process the event
| ev_data3 | text | Data field containing an argument needed to process the event
| ev_data4 | text | Data field containing an argument needed to process the event
| ev_data5 | text | Data field containing an argument needed to process the event
| ev_data6 | text | Data field containing an argument needed to process the event
| ev_data7 | text | Data field containing an argument needed to process the event
| ev_data8 | text | Data field containing an argument needed to process the event

Index - Schema schemadoc

## Table: sl_listen

Indicates how nodes listen to events from other nodes in the Slony-I network.

sl_listen Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
sl_node.no_id | li_origin | integer | PRIMARY KEY The ID # (from sl_node.no_id) of the node this listener is operating on
sl_path.pa_server#1 | li_provider | integer | PRIMARY KEY The ID # (from sl_node.no_id) of the source node for this listening event
sl_path.pa_client#1 | li_receiver | integer | PRIMARY KEY The ID # (from sl_node.no_id) of the target node for this listening event

Index - Schema schemadoc

## Table: sl_log_1

Stores each change to be propagated to subscriber nodes

sl_log_1 Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| log_origin | integer | Origin node from which the change came
| log_xid | schemadoc.xxid | Transaction ID on the origin node
| log_tableid | integer | The table ID (from sl_table.tab_id) that this log entry is to affect
| log_actionseq | bigint |
| log_cmdtype | character(1) | Replication action to take. U = Update, I = Insert, D = DELETE
| log_cmddata | text | The data needed to perform the log action

Index - Schema schemadoc

## Table: sl_log_2

Stores each change to be propagated to subscriber nodes

sl_log_2 Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| log_origin | integer | Origin node from which the change came
| log_xid | schemadoc.xxid | Transaction ID on the origin node
| log_tableid | integer | The table ID (from sl_table.tab_id) that this log entry is to affect
| log_actionseq | bigint |
| log_cmdtype | character(1) | Replication action to take. U = Update, I = Insert, D = DELETE
| log_cmddata | text | The data needed to perform the log action

Index - Schema schemadoc

## Table: sl_node

Holds the list of nodes associated with this namespace.

sl_node Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| no_id | integer | PRIMARY KEY The unique ID number for the node
| no_active | boolean | Is the node active in replication yet?
| no_comment | text | A human-oriented description of the node

Tables referencing this one via Foreign Key Constraints:

- sl_listen

- sl_path

- sl_set

- sl_setsync

Index - Schema schemadoc

## Table: sl_path

Holds connection information for the paths between nodes, and the synchronisation delay

sl_path Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
sl_node.no_id | pa_server | integer | PRIMARY KEY The Node ID # (from sl_node.no_id) of the data source
sl_node.no_id | pa_client | integer | PRIMARY KEY The Node ID # (from sl_node.no_id) of the data target
| pa_conninfo | text | NOT NULL The PostgreSQL connection string used to connect to the source node.
| pa_connretry | integer | The synchronisation delay, in seconds

Tables referencing this one via Foreign Key Constraints:

- sl_listen

- sl_subscribe

Index - Schema schemadoc

## View: sl_seqlastvalue

sl_seqlastvalue Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| seq_id | integer |
| seq_set | integer |
| seq_reloid | oid |
| seq_origin | integer |
| seq_last_value | bigint |

    SELECT sq.seq_id
    , sq.seq_set
    , sq.seq_reloid
    , s.set_origin AS seq_origin
    , schemadoc.sequencelastvalue
    (
         (
               (quote_ident
                     (
                           (pgn.nspname)::text
                     ) || '.'::text
               ) || quote_ident
               (
                     (pgc.relname)::text
               )
         )
    ) AS seq_last_value
    FROM schemadoc.sl_sequence sq
    , schemadoc.sl_set s
    , pg_class pgc
    , pg_namespace pgn
    WHERE (
         (
               (s.set_id = sq.seq_set)
             AND (pgc.oid = sq.seq_reloid)
         )
       AND (pgn.oid = pgc.relnamespace)
    );

Index - Schema schemadoc

## Table: sl_seqlog

Log of Sequence updates

sl_seqlog Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| seql_seqid | integer | Sequence ID
| seql_origin | integer | Publisher node at which the sequence originates
| seql_ev_seqno | bigint | Slony-I Event with which this sequence update is associated
| seql_last_value | bigint | Last value published for this sequence

Index - Schema schemadoc

## Table: sl_sequence

Similar to sl_table, each entry identifies a sequence being replicated.

sl_sequence Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| seq_id | integer | PRIMARY KEY An internally-used ID for Slony-I to use in its sequencing of updates
| seq_reloid | oid | UNIQUE NOT NULL The OID of the sequence object
sl_set.set_id | seq_set | integer | Indicates which replication set the object is in
| seq_comment | text | A human-oriented comment

Index - Schema schemadoc

## Table: sl_set

Holds definitions of replication sets.

sl_set Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| set_id | integer | PRIMARY KEY A unique ID number for the set.
sl_node.no_id | set_origin | integer | The ID number of the source node for the replication set.
| set_locked | schemadoc.xxid | Indicates whether or not the set is locked.
| set_comment | text | A human-oriented description of the set.

Tables referencing this one via Foreign Key Constraints:

- sl_sequence

- sl_setsync

- sl_subscribe

- sl_table

Index - Schema schemadoc

## Table: sl_setsync

Not documented yet

sl_setsync Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
sl_set.set_id | ssy_setid | integer | PRIMARY KEY ID number of the replication set
sl_node.no_id | ssy_origin | integer | ID number of the node
| ssy_seqno | bigint | Slony-I sequence number
| ssy_minxid | schemadoc.xxid | Earliest XID in provider system affected by SYNC
| ssy_maxxid | schemadoc.xxid | Latest XID in provider system affected by SYNC
| ssy_xip | text | Contains the list of XIDs in the SYNC in the order they should be applied
| ssy_action_list | text | The only time this field is used is during the subscription process. At the time a subscriber copies over data from the origin (not from another subscriber), it actually sees all tables in a state somewhere between two SYNC events. Therefore this list contains all action sequences that are visible, and therefore their operation already included in the data copied, at the time the initial data copy is done, so that those actions can be filtered out during the first SYNC after subscribing.

Index - Schema schemadoc

## Table: sl_subscribe

Holds a list of subscriptions on sets

sl_subscribe Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
sl_set.set_id | sub_set | integer | PRIMARY KEY ID # (from sl_set) of the set being subscribed to
sl_path.pa_server#1 | sub_provider | integer | ID# (from sl_node) of the node providing data
sl_path.pa_client#1 | sub_receiver | integer | PRIMARY KEY ID# (from sl_node) of the node receiving data from the provider
| sub_forward | boolean | Does this provider keep data in sl_log_1/sl_log_2 to allow it to be a provider for other nodes?
| sub_active | boolean | Has this subscription been activated? This is not set until the subscriber has received COPY data from the provider

Index - Schema schemadoc

## Table: sl_table

Holds information about the tables being replicated.

sl_table Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
| tab_id | integer | PRIMARY KEY Unique key for Slony-I to use to identify the table
| tab_reloid | oid | UNIQUE NOT NULL The OID of the table in pg_catalog.pg_class.oid
sl_set.set_id | tab_set | integer | ID of the replication set the table is in
| tab_idxname | name | NOT NULL The name of the primary index of the table
| tab_altered | boolean | NOT NULL Has the table been modified for replication?
| tab_comment | text | Human-oriented description of the table

Tables referencing this one via Foreign Key Constraints:

- sl_trigger

Index - Schema schemadoc

## Table: sl_trigger

Holds information about triggers on tables managed using Slony-I

sl_trigger Structure
F-Key | Name | Type | Description
--- | --- | --- | ---
sl_table.tab_id | trig_tabid | integer | PRIMARY KEY Slony-I ID number of table the trigger is on
| trig_tgname | name | PRIMARY KEY Indicates the name of a trigger

Index - Schema schemadoc

## Function: altertableforreplication( integer )

### Returns: integer

### Language: PLPGSQL

alterTableForReplication(tab_id) Sets up a table for replication. On the origin, this involves adding the "logTrigger()" trigger to the table. On a subscriber node, this involves disabling triggers and rules, and adding in the trigger that denies write access to replicated tables.

    declare
    	p_tab_id			alias for $1;
    	v_no_id				int4;
    	v_tab_row			record;
    	v_tab_fqname		text;
    	v_tab_attkind		text;
    	v_n					int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Get our local node ID
    	-- ----
    	v_no_id := schemadoc.getLocalNodeId('_schemadoc');

    	-- ----
    	-- Get the sl_table row and the current origin of the table.
    	-- Verify that the table currently is NOT in altered state.
    	-- ----
    	select T.tab_reloid, T.tab_set, T.tab_idxname, T.tab_altered,
    			S.set_origin, PGX.indexrelid,
    			"pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			"pg_catalog".quote_ident(PGC.relname) as tab_fqname
    			into v_tab_row
    			from schemadoc.sl_table T, schemadoc.sl_set S,
    				"pg_catalog".pg_class PGC, "pg_catalog".pg_namespace PGN,
    				"pg_catalog".pg_index PGX, "pg_catalog".pg_class PGXC
    			where T.tab_id = p_tab_id
    				and T.tab_set = S.set_id
    				and T.tab_reloid = PGC.oid
    				and PGC.relnamespace = PGN.oid
    				and PGX.indrelid = T.tab_reloid
    				and PGX.indexrelid = PGXC.oid
    				and PGXC.relname = T.tab_idxname
    				for update;
    	if not found then
    		raise exception 'Slony-I: Table with id % not found', p_tab_id;
    	end if;
    	v_tab_fqname = v_tab_row.tab_fqname;
    	if v_tab_row.tab_altered then
    		raise exception 'Slony-I: Table % is already in altered state',
    				v_tab_fqname;
    	end if;

    	v_tab_attkind := schemadoc.determineAttKindUnique(v_tab_row.tab_fqname,
    						v_tab_row.tab_idxname);

    	execute 'lock table ' || v_tab_fqname || ' in access exclusive mode';

    	-- ----
    	-- Procedures are different on origin and subscriber
    	-- ----
    	if v_no_id = v_tab_row.set_origin then
    		-- ----
    		-- On the Origin we add the log trigger to the table and done
    		-- ----
    		execute 'create trigger "_schemadoc_logtrigger_' ||
    				p_tab_id || '" after insert or update or delete on ' ||
    				v_tab_fqname || ' for each row execute procedure
    				schemadoc.logTrigger (''_schemadoc'', ''' ||
    					p_tab_id || ''', ''' ||
    					v_tab_attkind || ''');';
    	else
    		-- ----
    		-- On the subscriber the thing is a bit more difficult. We want
    		-- to disable all user- and foreign key triggers and rules.
    		-- ----

    		-- ----
    		-- Disable all existing triggers
    		-- ----
    		update "pg_catalog".pg_trigger
    				set tgrelid = v_tab_row.indexrelid
    				where tgrelid = v_tab_row.tab_reloid
    				and not exists (
    						select true from schemadoc.sl_table TAB,
    								schemadoc.sl_trigger TRIG
    								where TAB.tab_reloid = tgrelid
    								and TAB.tab_id = TRIG.trig_tabid
    								and TRIG.trig_tgname = tgname
    					);
    		get diagnostics v_n = row_count;
    		if v_n > 0 then
    			update "pg_catalog".pg_class
    					set reltriggers = reltriggers - v_n
    					where oid = v_tab_row.tab_reloid;
    		end if;

    		-- ----
    		-- Disable all existing rules
    		-- ----
    		update "pg_catalog".pg_rewrite
    				set ev_class = v_tab_row.indexrelid
    				where ev_class = v_tab_row.tab_reloid;
    		get diagnostics v_n = row_count;
    		if v_n > 0 then
    			update "pg_catalog".pg_class
    					set relhasrules = false
    					where oid = v_tab_row.tab_reloid;
    		end if;

    		-- ----
    		-- Add the trigger that denies write access to replicated tables
    		-- ----
    		execute 'create trigger "_schemadoc_denyaccess_' ||
    				p_tab_id || '" before insert or update or delete on ' ||
    				v_tab_fqname || ' for each row execute procedure
    				schemadoc.denyAccess (''_schemadoc'');';
    	end if;

    	-- ----
    	-- Mark the table altered in our configuration
    	-- ----
    	update schemadoc.sl_table
    			set tab_altered = true where tab_id = p_tab_id;

    	return p_tab_id;
    end;

## Function: altertablerestore( integer )

### Returns: integer

### Language: PLPGSQL

alterTableRestore (tab_id) Restores table tab_id from being replicated. On the origin, this simply involves dropping the "logtrigger" trigger. On subscriber nodes, this involves dropping the "denyaccess" trigger, and restoring user triggers and rules.

    declare
    	p_tab_id			alias for $1;
    	v_no_id				int4;
    	v_tab_row			record;
    	v_tab_fqname		text;
    	v_n					int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Get our local node ID
    	-- ----
    	v_no_id := schemadoc.getLocalNodeId('_schemadoc');

    	-- ----
    	-- Get the sl_table row and the current tables origin. Check
    	-- that the table currently IS in altered state.
    	-- ----
    	select T.tab_reloid, T.tab_set, T.tab_altered,
    			S.set_origin, PGX.indexrelid,
    			"pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			"pg_catalog".quote_ident(PGC.relname) as tab_fqname
    			into v_tab_row
    			from schemadoc.sl_table T, schemadoc.sl_set S,
    				"pg_catalog".pg_class PGC, "pg_catalog".pg_namespace PGN,
    				"pg_catalog".pg_index PGX, "pg_catalog".pg_class PGXC
    			where T.tab_id = p_tab_id
    				and T.tab_set = S.set_id
    				and T.tab_reloid = PGC.oid
    				and PGC.relnamespace = PGN.oid
    				and PGX.indrelid = T.tab_reloid
    				and PGX.indexrelid = PGXC.oid
    				and PGXC.relname = T.tab_idxname
    				for update;
    	if not found then
    		raise exception 'Slony-I: Table with id % not found', p_tab_id;
    	end if;
    	v_tab_fqname = v_tab_row.tab_fqname;
    	if not v_tab_row.tab_altered then
    		raise exception 'Slony-I: Table % is not in altered state',
    				v_tab_fqname;
    	end if;

    	execute 'lock table ' || v_tab_fqname || ' in access exclusive mode';

    	-- ----
    	-- Procedures are different on origin and subscriber
    	-- ----
    	if v_no_id = v_tab_row.set_origin then
    		-- ----
    		-- On the Origin we just drop the trigger we originally added
    		-- ----
    		execute 'drop trigger "_schemadoc_logtrigger_' ||
    				p_tab_id || '" on ' || v_tab_fqname;
    	else
    		-- ----
    		-- On the subscriber drop the denyAccess trigger
    		-- ----
    		execute 'drop trigger "_schemadoc_denyaccess_' ||
    				p_tab_id || '" on ' || v_tab_fqname;

    		-- ----
    		-- Restore all original triggers
    		-- ----
    		update "pg_catalog".pg_trigger
    				set tgrelid = v_tab_row.tab_reloid
    				where tgrelid = v_tab_row.indexrelid;
    		get diagnostics v_n = row_count;
    		if v_n > 0 then
    			update "pg_catalog".pg_class
    					set reltriggers = reltriggers + v_n
    					where oid = v_tab_row.tab_reloid;
    		end if;

    		-- ----
    		-- Restore all original rewrite rules
    		-- ----
    		update "pg_catalog".pg_rewrite
    				set ev_class = v_tab_row.tab_reloid
    				where ev_class = v_tab_row.indexrelid;
    		get diagnostics v_n = row_count;
    		if v_n > 0 then
    			update "pg_catalog".pg_class
    					set relhasrules = true
    					where oid = v_tab_row.tab_reloid;
    		end if;

    	end if;

    	-- ----
    	-- Mark the table not altered in our configuration
    	-- ----
    	update schemadoc.sl_table
    			set tab_altered = false where tab_id = p_tab_id;

    	return p_tab_id;
    end;

## Function: cleanupevent( )

### Returns: integer

### Language: PLPGSQL

cleaning old data out of sl_confirm, sl_event. Removes all but the last sl_confirm row per (origin,receiver), and then removes all events that are confirmed by all nodes in the whole cluster up to the last SYNC.

    declare
    	v_max_row	record;
    	v_min_row	record;
    	v_max_sync	int8;
    begin
    	-- ----
    	-- First remove all but the oldest confirm row per origin,receiver pair
    	-- ----
    	delete from schemadoc.sl_confirm
    				where con_origin not in (select no_id from schemadoc.sl_node);
    	delete from schemadoc.sl_confirm
    				where con_received not in (select no_id from schemadoc.sl_node);
    	-- ----
    	-- Next remove all but the oldest confirm row per origin,receiver pair.
    	-- Ignore confirmations that are younger than 10 minutes. We currently
    	-- have an not confirmed suspicion that a possibly lost transaction due
    	-- to a server crash might have been visible to another session, and
    	-- that this led to log data that is needed again got removed.
    	-- ----
    	for v_max_row in select con_origin, con_received, max(con_seqno) as con_seqno
    				from schemadoc.sl_confirm
    				where con_timestamp < (CURRENT_TIMESTAMP - '10 min'::interval)
    				group by con_origin, con_received
    	loop
    		delete from schemadoc.sl_confirm
    				where con_origin = v_max_row.con_origin
    				and con_received = v_max_row.con_received
    				and con_seqno < v_max_row.con_seqno;
    	end loop;

    	-- ----
    	-- Then remove all events that are confirmed by all nodes in the
    	-- whole cluster up to the last SYNC
    	-- ----
    	for v_min_row in select con_origin, min(con_seqno) as con_seqno
    				from schemadoc.sl_confirm
    				group by con_origin
    	loop
    		select coalesce(max(ev_seqno), 0) into v_max_sync
    				from schemadoc.sl_event
    				where ev_origin = v_min_row.con_origin
    				and ev_seqno <= v_min_row.con_seqno
    				and ev_type = 'SYNC';
    		if v_max_sync > 0 then
    			delete from schemadoc.sl_event
    					where ev_origin = v_min_row.con_origin
    					and ev_seqno < v_max_sync;
    		end if;
    	end loop;

    	return 0;
    end;

## Function: cleanuplistener( )

### Returns: integer

### Language: C

look for stale pg_listener entries and submit Async_Unlisten() to them

    _Slony_I_cleanupListener

## Function: createevent( name, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text, text, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text, text, text, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text, text, text, text, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text, text, text, text, text, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: createevent( name, text, text, text, text, text, text, text, text, text )

### Returns: bigint

### Language: C

FUNCTION createEvent (cluster_name, ev_type [, ev_data [...]]) Create an sl_event entry

    _Slony_I_createEvent

## Function: ddlscript( integer, text, integer )

### Returns: bigint

### Language: PLPGSQL

ddlScript(set_id, script, only_on_node) Generates a SYNC event, runs the script on the origin, and then generates a DDL_SCRIPT event to request it to be run on replicated slaves.

    declare
    	p_set_id			alias for $1;
    	p_script			alias for $2;
    	p_only_on_node		alias for $3;
    	v_set_origin		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that the set exists and originates here
    	-- ----
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_set_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_set_origin <> schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_set_id;
    	end if;

    	-- ----
    	-- Create a SYNC event, run the script and generate the DDL_SCRIPT event
    	-- ----
    	perform schemadoc.createEvent('_schemadoc', 'SYNC', NULL);
    	perform schemadoc.ddlScript_int(p_set_id, p_script, p_only_on_node);
    	return  schemadoc.createEvent('_schemadoc', 'DDL_SCRIPT',
    			p_set_id, p_script, p_only_on_node);
    end;

## Function: ddlscript_int( integer, text, integer )

### Returns: integer

### Language: PLPGSQL

ddlScript_int(set_id, script, only_on_node) Processes the DDL_SCRIPT event. On slave nodes, this restores original triggers/rules, runs the script, and then puts tables back into replicated mode.

    declare
    	p_set_id			alias for $1;
    	p_script			alias for $2;
    	p_only_on_node		alias for $3;
    	v_set_origin		int4;
    	v_no_id				int4;
    	v_row				record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that we either are the set origin or a current
    	-- subscriber of the set.
    	-- ----
    	v_no_id := schemadoc.getLocalNodeId('_schemadoc');
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_set_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_set_origin <> v_no_id
    			and not exists (select 1 from schemadoc.sl_subscribe
    						where sub_set = p_set_id
    						and sub_receiver = v_no_id)
    	then
    		return 0;
    	end if;

    	-- ----
    	-- If execution on only one node is requested, check that
    	-- we are that node.
    	-- ----
    	if p_only_on_node > 0 and p_only_on_node <> v_no_id then
    		return 0;
    	end if;

    	-- ----
    	-- Restore all original triggers and rules
    	-- ----
    	for v_row in select * from schemadoc.sl_table
    			where tab_set = p_set_id
    	loop
    		perform schemadoc.alterTableRestore(v_row.tab_id);
    	end loop;

    	-- ----
    	-- Run the script
    	-- ----
    	execute p_script;

    	-- ----
    	-- Put all tables back into replicated mode
    	-- ----
    	for v_row in select * from schemadoc.sl_table
    			where tab_set = p_set_id
    	loop
    		perform schemadoc.alterTableForReplication(v_row.tab_id);
    	end loop;

    	return p_set_id;
    end;

## Function: denyaccess( )

### Returns: "trigger"

### Language: C

Trigger function to prevent modifications to a table on a subscriber

    _Slony_I_denyAccess

## Function: determineattkindserial( text )

### Returns: text

### Language: PLPGSQL

determineAttKindSerial (tab_fqname) A table was that was specified without a primary key is added to the replication. Assume that tableAddKey() was called before and finish the creation of the serial column. The return an attkind according to that.

    declare
    	p_tab_fqname	alias for $1;
    	v_attkind		text default '';
    	v_attrow		record;
    	v_have_serial	bool default 'f';
    begin
    	--
    	-- Loop over the attributes of this relation
    	-- and add a "v" for every user column, and a "k"
    	-- if we find the Slony-I special serial column.
    	--
    	for v_attrow in select PGA.attnum, PGA.attname
    			from "pg_catalog".pg_class PGC,
    			    "pg_catalog".pg_namespace PGN,
    				"pg_catalog".pg_attribute PGA
    			where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			    "pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    				and PGN.oid = PGC.relnamespace
    				and PGA.attrelid = PGC.oid
    				and not PGA.attisdropped
    				and PGA.attnum > 0
    			order by attnum
    	loop
    		if v_attrow.attname = '_Slony-I_schemadoc_rowID' then
    		    v_attkind := v_attkind || 'k';
    			v_have_serial := 't';
    		else
    			v_attkind := v_attkind || 'v';
    		end if;
    	end loop;

    	--
    	-- A table must have at least one attribute, so not finding
    	-- anything means the table does not exist.
    	--
    	if not found then
    		raise exception 'Slony-I: table % not found', p_tab_fqname;
    	end if;

    	--
    	-- If it does not have the special serial column, we
    	-- should not have been called in the first place.
    	--
    	if not v_have_serial then
    		raise exception 'Slony-I: table % does not have the serial key',
    				p_tab_fqname;
    	end if;

    	execute 'update ' || p_tab_fqname ||
    		' set "_Slony-I_schemadoc_rowID" =' ||
    		' "pg_catalog".nextval(''schemadoc.sl_rowid_seq'');';
    	execute 'alter table only ' || p_tab_fqname ||
    		' add unique ("_Slony-I_schemadoc_rowID");';
    	execute 'alter table only ' || p_tab_fqname ||
    		' alter column "_Slony-I_schemadoc_rowID" ' ||
    		' set not null;';

    	--
    	-- Return the resulting Slony-I attkind
    	--
    	return v_attkind;
    end;

## Function: determineattkindunique( text, name )

### Returns: text

### Language: PLPGSQL

determineAttKindUnique (tab_fqname, indexname) Given a tablename, return the Slony-I specific attkind (used for the log trigger) of the table. Use the specified unique index or the primary key (if indexname is NULL).

    declare
    	p_tab_fqname	alias for $1;
    	p_idx_name		alias for $2;
    	v_idxrow		record;
    	v_attrow		record;
    	v_i				integer;
    	v_attno			int2;
    	v_attkind		text default '';
    	v_attfound		bool;
    begin
    	--
    	-- Lookup the tables primary key or the specified unique index
    	--
    	if p_idx_name isnull then
    		raise exception 'Slony-I: index name must be specified';
    	else
    		select PGXC.relname, PGX.indexrelid, PGX.indkey
    				into v_idxrow
    				from "pg_catalog".pg_class PGC,
    					"pg_catalog".pg_namespace PGN,
    					"pg_catalog".pg_index PGX,
    					"pg_catalog".pg_class PGXC
    				where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    					"pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    					and PGN.oid = PGC.relnamespace
    					and PGX.indrelid = PGC.oid
    					and PGX.indexrelid = PGXC.oid
    					and PGX.indisunique
    					and PGXC.relname = p_idx_name;
    		if not found then
    			raise exception 'Slony-I: table % has no unique index %',
    					p_tab_fqname, p_idx_name;
    		end if;
    	end if;

    	--
    	-- Loop over the tables attributes and check if they are
    	-- index attributes. If so, add a "k" to the return value,
    	-- otherwise add a "v".
    	--
    	for v_attrow in select PGA.attnum, PGA.attname
    			from "pg_catalog".pg_class PGC,
    			    "pg_catalog".pg_namespace PGN,
    				"pg_catalog".pg_attribute PGA
    			where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			    "pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    				and PGN.oid = PGC.relnamespace
    				and PGA.attrelid = PGC.oid
    				and not PGA.attisdropped
    				and PGA.attnum > 0
    			order by attnum
    	loop
    		v_attfound = 'f';

    		v_i := 0;
    		loop
    			select indkey[v_i] into v_attno from "pg_catalog".pg_index
    					where indexrelid = v_idxrow.indexrelid;
    			if v_attno = 0 then
    				exit;
    			end if;
    			if v_attrow.attnum = v_attno then
    				v_attfound = 't';
    				exit;
    			end if;
    			v_i := v_i + 1;
    		end loop;

    		if v_attfound then
    			v_attkind := v_attkind || 'k';
    		else
    			v_attkind := v_attkind || 'v';
    		end if;
    	end loop;

    	--
    	-- Return the resulting attkind
    	--
    	return v_attkind;
    end;

## Function: determineidxnameserial( text )

### Returns: name

### Language: PLPGSQL

determineIdxnameSerial (tab_fqname) Given a tablename, construct the index name of the serial column.

    declare
    	p_tab_fqname	alias for $1;
    	v_row			record;
    begin
    	--
    	-- Lookup the table name alone
    	--
    	select PGC.relname
    			into v_row
    			from "pg_catalog".pg_class PGC,
    				"pg_catalog".pg_namespace PGN
    			where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    				"pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    				and PGN.oid = PGC.relnamespace;
    	if not found then
    		raise exception 'Slony-I: table % not found',
    				p_tab_fqname;
    	end if;

    	--
    	-- Return the found index name
    	--
    	return v_row.relname || '__Slony-I_schemadoc_rowID_key';
    end;

## Function: determineidxnameunique( text, name )

### Returns: name

### Language: PLPGSQL

FUNCTION determineIdxnameUnique (tab_fqname, indexname) Given a tablename, tab_fqname, check that the unique index, indexname, exists or return the primary key index name for the table. If there is no unique index, it raises an exception.

    declare
    	p_tab_fqname	alias for $1;
    	p_idx_name		alias for $2;
    	v_idxrow		record;
    begin
    	--
    	-- Lookup the tables primary key or the specified unique index
    	--
    	if p_idx_name isnull then
    		select PGXC.relname
    				into v_idxrow
    				from "pg_catalog".pg_class PGC,
    					"pg_catalog".pg_namespace PGN,
    					"pg_catalog".pg_index PGX,
    					"pg_catalog".pg_class PGXC
    				where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    					"pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    					and PGN.oid = PGC.relnamespace
    					and PGX.indrelid = PGC.oid
    					and PGX.indexrelid = PGXC.oid
    					and PGX.indisprimary;
    		if not found then
    			raise exception 'Slony-I: table % has no primary key',
    					p_tab_fqname;
    		end if;
    	else
    		select PGXC.relname
    				into v_idxrow
    				from "pg_catalog".pg_class PGC,
    					"pg_catalog".pg_namespace PGN,
    					"pg_catalog".pg_index PGX,
    					"pg_catalog".pg_class PGXC
    				where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    					"pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    					and PGN.oid = PGC.relnamespace
    					and PGX.indrelid = PGC.oid
    					and PGX.indexrelid = PGXC.oid
    					and PGX.indisunique
    					and PGXC.relname = p_idx_name;
    		if not found then
    			raise exception 'Slony-I: table % has no unique index %',
    					p_tab_fqname, p_idx_name;
    		end if;
    	end if;

    	--
    	-- Return the found index name
    	--
    	return v_idxrow.relname;
    end;

## Function: disablenode( integer )

### Returns: bigint

### Language: PLPGSQL

process DISABLE_NODE event for node no_id NOTE: This is not yet implemented!

    declare
    	p_no_id			alias for $1;
    begin
    	-- **** TODO ****
    	raise exception 'Slony-I: disableNode() not implemented';
    end;

## Function: disablenode_int( integer )

### Returns: integer

### Language: PLPGSQL

    declare
    	p_no_id			alias for $1;
    begin
    	-- **** TODO ****
    	raise exception 'Slony-I: disableNode_int() not implemented';
    end;

## Function: droplisten( integer, integer, integer )

### Returns: bigint

### Language: PLPGSQL

dropListen (li_origin, li_provider, li_receiver) Generate the DROP_LISTEN event.

    declare
    	p_li_origin		alias for $1;
    	p_li_provider	alias for $2;
    	p_li_receiver	alias for $3;
    begin
    	perform schemadoc.dropListen_int(p_li_origin,
    			p_li_provider, p_li_receiver);

    	return  schemadoc.createEvent ('_schemadoc', 'DROP_LISTEN',
    			p_li_origin, p_li_provider, p_li_receiver);
    end;

## Function: droplisten_int( integer, integer, integer )

### Returns: integer

### Language: PLPGSQL

dropListen (li_origin, li_provider, li_receiver) Process the DROP_LISTEN event, deleting the sl_listen entry for the indicated (origin,provider,receiver) combination.

    declare
    	p_li_origin		alias for $1;
    	p_li_provider	alias for $2;
    	p_li_receiver	alias for $3;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	delete from schemadoc.sl_listen
    			where li_origin = p_li_origin
    			and li_provider = p_li_provider
    			and li_receiver = p_li_receiver;
    	if found then
    		return 1;
    	else
    		return 0;
    	end if;
    end;

## Function: dropnode( integer )

### Returns: bigint

### Language: PLPGSQL

generate DROP_NODE event to drop node node_id from replication

    declare
    	p_no_id			alias for $1;
    	v_node_row		record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that this got called on a different node
    	-- ----
    	if p_no_id = schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: DROP_NODE cannot initiate on the dropped node';
    	end if;

    	select * into v_node_row from schemadoc.sl_node
    			where no_id = p_no_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: unknown node ID %', p_no_id;
    	end if;

    	-- ----
    	-- Make sure we do not break other nodes subscriptions with this
    	-- ----
    	if exists (select true from schemadoc.sl_subscribe
    			where sub_provider = p_no_id)
    	then
    		raise exception 'Slony-I: Node % is still configured as data provider',
    				p_no_id;
    	end if;

    	-- ----
    	-- Make sure no set originates there any more
    	-- ----
    	if exists (select true from schemadoc.sl_set
    			where set_origin = p_no_id)
    	then
    		raise exception 'Slony-I: Node % is still origin of one or more sets',
    				p_no_id;
    	end if;

    	-- ----
    	-- Call the internal drop functionality and generate the event
    	-- ----
    	perform schemadoc.dropNode_int(p_no_id);
    	return  schemadoc.createEvent('_schemadoc', 'DROP_NODE',
    									p_no_id);
    end;

## Function: dropnode_int( integer )

### Returns: integer

### Language: PLPGSQL

internal function to process DROP_NODE event to drop node node_id from replication

    declare
    	p_no_id			alias for $1;
    	v_tab_row		record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- If the dropped node is a remote node, clean the configuration
    	-- from all traces for it.
    	-- ----
    	if p_no_id <> schemadoc.getLocalNodeId('_schemadoc') then
    		delete from schemadoc.sl_subscribe
    				where sub_receiver = p_no_id;
    		delete from schemadoc.sl_listen
    				where li_origin = p_no_id
    					or li_provider = p_no_id
    					or li_receiver = p_no_id;
    		delete from schemadoc.sl_path
    				where pa_server = p_no_id
    					or pa_client = p_no_id;
    		delete from schemadoc.sl_confirm
    				where con_origin = p_no_id
    					or con_received = p_no_id;
    		delete from schemadoc.sl_event
    				where ev_origin = p_no_id;
    		delete from schemadoc.sl_node
    				where no_id = p_no_id;

    		return p_no_id;
    	end if;

    	-- ----
    	-- This is us ... deactivate the node for now, the daemon
    	-- will call uninstallNode() in a separate transaction.
    	-- ----
    	update schemadoc.sl_node
    			set no_active = false
    			where no_id = p_no_id;

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	return p_no_id;
    end;

## Function: droppath( integer, integer )

### Returns: bigint

### Language: PLPGSQL

Generate DROP_PATH event to drop path from pa_server to pa_client

    declare
    	p_pa_server		alias for $1;
    	p_pa_client		alias for $2;
    	v_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- There should be no existing subscriptions. Auto unsubscribing
    	-- is considered too dangerous.
    	-- ----
    	for v_row in select sub_set, sub_provider, sub_receiver
    			from schemadoc.sl_subscribe
    			where sub_provider = p_pa_server
    			and sub_receiver = p_pa_client
    	loop
    		raise exception
    			'Slony-I: Path cannot be dropped, subscription of set % needs it',
    			v_row.sub_set;
    	end loop;

    	-- ----
    	-- Drop all sl_listen entries that depend on this path
    	-- ----
    	for v_row in select li_origin, li_provider, li_receiver
    			from schemadoc.sl_listen
    			where li_provider = p_pa_server
    			and li_receiver = p_pa_client
    	loop
    		perform schemadoc.dropListen(
    				v_row.li_origin, v_row.li_provider, v_row.li_receiver);
    	end loop;

    	-- ----
    	-- Now drop the path and create the event
    	-- ----
    	perform schemadoc.dropPath_int(p_pa_server, p_pa_client);

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	return  schemadoc.createEvent ('_schemadoc', 'DROP_PATH',
    			p_pa_server, p_pa_client);
    end;

## Function: droppath_int( integer, integer )

### Returns: integer

### Language: PLPGSQL

Process DROP_PATH event to drop path from pa_server to pa_client

    declare
    	p_pa_server		alias for $1;
    	p_pa_client		alias for $2;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Remove any dangling sl_listen entries with the server
    	-- as provider and the client as receiver. This must have
    	-- been cleared out before, but obviously was not.
    	-- ----
    	delete from schemadoc.sl_listen
    			where li_provider = p_pa_server
    			and li_receiver = p_pa_client;

    	delete from schemadoc.sl_path
    			where pa_server = p_pa_server
    			and pa_client = p_pa_client;

    	if found then
    		-- Rewrite sl_listen table
    		perform schemadoc.RebuildListenEntries();

    		return 1;
    	else
    		-- Rewrite sl_listen table
    		perform schemadoc.RebuildListenEntries();

    		return 0;
    	end if;
    end;

## Function: dropset( integer )

### Returns: bigint

### Language: PLPGSQL

Process DROP_SET event to drop replication of set set_id. This involves: - Restoring original triggers and rules - Removing all traces of the set configuration, including sequences, tables, subscribers, syncs, and the set itself

    declare
    	p_set_id			alias for $1;
    	v_origin			int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that the set exists and originates here
    	-- ----
    	select set_origin into v_origin from schemadoc.sl_set
    			where set_id = p_set_id;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_set_id;
    	end if;

    	-- ----
    	-- Call the internal drop set functionality and generate the event
    	-- ----
    	perform schemadoc.dropSet_int(p_set_id);
    	return  schemadoc.createEvent('_schemadoc', 'DROP_SET',
    			p_set_id);
    end;

## Function: dropset_int( integer )

### Returns: integer

### Language: PLPGSQL

    declare
    	p_set_id			alias for $1;
    	v_tab_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Restore all tables original triggers and rules and remove
    	-- our replication stuff.
    	-- ----
    	for v_tab_row in select tab_id from schemadoc.sl_table
    			where tab_set = p_set_id
    			order by tab_id
    	loop
    		perform schemadoc.alterTableRestore(v_tab_row.tab_id);
    		perform schemadoc.tableDropKey(v_tab_row.tab_id);
    	end loop;

    	-- ----
    	-- Remove all traces of the set configuration
    	-- ----
    	delete from schemadoc.sl_sequence
    			where seq_set = p_set_id;
    	delete from schemadoc.sl_table
    			where tab_set = p_set_id;
    	delete from schemadoc.sl_subscribe
    			where sub_set = p_set_id;
    	delete from schemadoc.sl_setsync
    			where ssy_setid = p_set_id;
    	delete from schemadoc.sl_set
    			where set_id = p_set_id;

    	-- Regenerate sl_listen since we revised the subscriptions
    	perform schemadoc.RebuildListenEntries();

    	return p_set_id;
    end;

## Function: droptrigger( integer, name )

### Returns: bigint

### Language: PLPGSQL

dropTrigger (trig_tabid, trig_tgname) Submits DROP_TRIGGER event to indicate that trigger trig_tgname on replicated table trig_tabid WILL be disabled.

    declare
    	p_trig_tabid		alias for $1;
    	p_trig_tgname		alias for $2;
    begin
    	perform schemadoc.dropTrigger_int(p_trig_tabid, p_trig_tgname);
    	return  schemadoc.createEvent('_schemadoc', 'DROP_TRIGGER',
    			p_trig_tabid, p_trig_tgname);
    end;

## Function: droptrigger_int( integer, name )

### Returns: integer

### Language: PLPGSQL

dropTrigger_int (trig_tabid, trig_tgname) Processes DROP_TRIGGER event to make sure that trigger trig_tgname on replicated table trig_tabid IS disabled.

    declare
    	p_trig_tabid		alias for $1;
    	p_trig_tgname		alias for $2;
    	v_tab_altered		boolean;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Get the current table status (altered or not)
    	-- ----
    	select tab_altered into v_tab_altered
    			from schemadoc.sl_table where tab_id = p_trig_tabid;
    	if not found then
    		-- ----
    		-- Not found is no hard error here, because that might
    		-- mean that we are not subscribed to that set
    		-- ----
    		return 0;
    	end if;

    	-- ----
    	-- If the table is modified for replication, restore the original state
    	-- ----
    	if v_tab_altered then
    		perform schemadoc.alterTableRestore(p_trig_tabid);
    	end if;

    	-- ----
    	-- Remove the entry from sl_trigger
    	-- ----
    	delete from schemadoc.sl_trigger
    			where trig_tabid = p_trig_tabid
    			  and trig_tgname = p_trig_tgname;

    	-- ----
    	-- Put the table back into replicated state if it was
    	-- ----
    	if v_tab_altered then
    		perform schemadoc.alterTableForReplication(p_trig_tabid);
    	end if;

    	return p_trig_tabid;
    end;

## Function: enablenode( integer )

### Returns: bigint

### Language: PLPGSQL

no_id - Node ID # Generate the ENABLE_NODE event for node no_id

    declare
    	p_no_id			alias for $1;
    	v_local_node_id	int4;
    	v_node_row		record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that we are the node to activate and that we are
    	-- currently disabled.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select * into v_node_row
    			from schemadoc.sl_node
    			where no_id = p_no_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: node % not found', p_no_id;
    	end if;
    	if v_node_row.no_active then
    		raise exception 'Slony-I: node % is already active', p_no_id;
    	end if;

    	-- ----
    	-- Activate this node and generate the ENABLE_NODE event
    	-- ----
    	perform schemadoc.enableNode_int (p_no_id);
    	return  schemadoc.createEvent('_schemadoc', 'ENABLE_NODE',
    									p_no_id);
    end;

## Function: enablenode_int( integer )

### Returns: integer

### Language: PLPGSQL

no_id - Node ID # Internal function to process the ENABLE_NODE event for node no_id

    declare
    	p_no_id			alias for $1;
    	v_local_node_id	int4;
    	v_node_row		record;
    	v_sub_row		record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that the node is inactive
    	-- ----
    	select * into v_node_row
    			from schemadoc.sl_node
    			where no_id = p_no_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: node % not found', p_no_id;
    	end if;
    	if v_node_row.no_active then
    		return p_no_id;
    	end if;

    	-- ----
    	-- Activate the node and generate sl_confirm status rows for it.
    	-- ----
    	update schemadoc.sl_node
    			set no_active = 't'
    			where no_id = p_no_id;
    	insert into schemadoc.sl_confirm
    			(con_origin, con_received, con_seqno)
    			select no_id, p_no_id, 0 from schemadoc.sl_node
    				where no_id != p_no_id
    				and no_active;
    	insert into schemadoc.sl_confirm
    			(con_origin, con_received, con_seqno)
    			select p_no_id, no_id, 0 from schemadoc.sl_node
    				where no_id != p_no_id
    				and no_active;

    	-- ----
    	-- Generate ENABLE_SUBSCRIPTION events for all sets that
    	-- origin here and are subscribed by the just enabled node.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	for v_sub_row in select SUB.sub_set, SUB.sub_provider from
    			schemadoc.sl_set S,
    			schemadoc.sl_subscribe SUB
    			where S.set_origin = v_local_node_id
    			and S.set_id = SUB.sub_set
    			and SUB.sub_receiver = p_no_id
    			for update of S
    	loop
    		perform schemadoc.enableSubscription (v_sub_row.sub_set,,
    				v_sub_row.sub_provider, p_no_id);
    	end loop;

    	return p_no_id;
    end;

## Function: enablesubscription( integer, integer, integer )

### Returns: integer

### Language: PLPGSQL

enableSubscription (sub_set, sub_provider, sub_receiver) Indicates that sub_receiver intends subscribing to set sub_set from sub_provider. Work is all done by the internal function enableSubscription_int (sub_set, sub_provider, sub_receiver).

    declare
    	p_sub_set			alias for $1;
    	p_sub_provider		alias for $2;
    	p_sub_receiver		alias for $3;
    begin
    	return  schemadoc.enableSubscription_int (p_sub_set,
    			p_sub_provider, p_sub_receiver);
    end;

## Function: enablesubscription_int( integer, integer, integer )

### Returns: integer

### Language: PLPGSQL

enableSubscription_int (sub_set, sub_provider, sub_receiver) Internal function to enable subscription of node sub_receiver to set sub_set via node sub_provider. slon does most of the work; all we need do here is to remember that it happened. The function updates sl_subscribe, indicating that the subscription has become active.

    declare
    	p_sub_set			alias for $1;
    	p_sub_provider		alias for $2;
    	p_sub_receiver		alias for $3;
    	v_n					int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- The real work is done in the replication engine. All
    	-- we have to do here is remembering that it happened.
    	-- ----
    	update schemadoc.sl_subscribe
    			set sub_active = 't'
    			where sub_set = p_sub_set
    			and sub_receiver = p_sub_receiver;
    	get diagnostics v_n = row_count;
    	if v_n = 0 then
    		insert into schemadoc.sl_subscribe
    				(sub_set, sub_provider, sub_receiver,
    				sub_forward, sub_active)
    				values
    				(p_sub_set, p_sub_provider, p_sub_receiver,
    				false, true);
    	end if;

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	return p_sub_set;
    end;

## Function: failednode( integer, integer )

### Returns: integer

### Language: PLPGSQL

Initiate failover from failed_node to backup_node. This function must be called on all nodes, and then waited for the restart of all node daemons.

    declare
    	p_failed_node		alias for $1;
    	p_backup_node		alias for $2;
    	v_row				record;
    	v_row2				record;
    	v_n					int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- All consistency checks first
    	-- Check that every system that has a path to the failed node
    	-- also has a path to the backup node.
    	-- ----
    	for v_row in select P.pa_client
    			from schemadoc.sl_path P
    			where P.pa_server = p_failed_node
    				and P.pa_client <> p_backup_node
    				and not exists (select true from schemadoc.sl_path PP
    							where PP.pa_server = p_backup_node
    								and PP.pa_client = P.pa_client)
    	loop
    		raise exception 'Slony-I: cannot failover - node % has no path to the backup node',
    				v_row.pa_client;
    	end loop;

    	-- ----
    	-- Check all sets originating on the failed node
    	-- ----
    	for v_row in select set_id
    			from schemadoc.sl_set
    			where set_origin = p_failed_node
    	loop
    		-- ----
    		-- Check that the backup node is subscribed to all sets
    		-- that origin on the failed node
    		-- ----
    		select into v_row2 sub_forward, sub_active
    				from schemadoc.sl_subscribe
    				where sub_set = v_row.set_id
    					and sub_receiver = p_backup_node;
    		if not found then
    			raise exception 'Slony-I: cannot failover - node % is not subscribed to set %',
    					p_backup_node, v_row.set_id;
    		end if;

    		-- ----
    		-- Check that the subscription is active
    		-- ----
    		if not v_row2.sub_active then
    			raise exception 'Slony-I: cannot failover - subscription for set % is not active',
    					v_row.set_id;
    		end if;

    		-- ----
    		-- If there are other subscribers, the backup node needs to
    		-- be a forwarder too.
    		-- ----
    		select into v_n count(*)
    				from schemadoc.sl_subscribe
    				where sub_set = v_row.set_id
    					and sub_receiver <> p_backup_node;
    		if v_n > 0 and not v_row2.sub_forward then
    			raise exception 'Slony-I: cannot failover - node % is not a forwarder of set %',
    					p_backup_node, v_row.set_id;
    		end if;
    	end loop;

    	-- ----
    	-- Terminate all connections of the failed node the hard way
    	-- ----
    	perform schemadoc.terminateNodeConnections(
    			'_schemadoc_Node_' || p_failed_node);

    -- Note that the following code should all become obsolete in the wake
    -- of the availability of RebuildListenEntries()...

    	-- ----
    	-- Let every node that listens for something on the failed node
    	-- listen for that on the backup node instead.
    	-- ----
    	for v_row in select * from schemadoc.sl_listen
    			where li_provider = p_failed_node
    				and li_receiver <> p_backup_node
    	loop
    		perform schemadoc.storeListen_int(v_row.li_origin,
    				p_backup_node, v_row.li_receiver);
    	end loop;

    	-- ----
    	-- Let the backup node listen for all events where the
    	-- failed node did listen for it.
    	-- ----
    	for v_row in select li_origin, li_provider
    			from schemadoc.sl_listen
    			where li_receiver = p_failed_node
    				and li_provider <> p_backup_node
    	loop
    		perform schemadoc.storeListen_int(v_row.li_origin,
    				v_row.li_provider, p_backup_node);
    	end loop;

    	-- ----
    	-- Remove all sl_listen entries that receive anything from the
    	-- failed node.
    	-- ----
    	delete from schemadoc.sl_listen
    			where li_provider = p_failed_node
    				or li_receiver = p_failed_node;

    	-- ----
    	-- Move the sets
    	-- ----
    	for v_row in select S.set_id, (select count(*)
    					from schemadoc.sl_subscribe SUB
    					where S.set_id = SUB.sub_set
    						and SUB.sub_receiver <> p_backup_node
    						and SUB.sub_provider = p_failed_node)
    					as num_direct_receivers
    			from schemadoc.sl_set S
    			where S.set_origin = p_failed_node
    			for update
    	loop
    		-- ----
    		-- If the backup node is the only direct subscriber ...
    		-- ----
    		if v_row.num_direct_receivers = 0 then
    raise notice 'failedNode: set % has no other direct receivers - move now', v_row.set_id;
    			-- ----
    			-- backup_node is the only direct subscriber, move the set
    			-- right now. On the backup node itself that includes restoring
    			-- all user mode triggers, removing the protection trigger,
    			-- adding the log trigger, removing the subscription and the
    			-- obsolete setsync status.
    			-- ----
    			if p_backup_node = schemadoc.getLocalNodeId('_schemadoc') then
    				for v_row2 in select * from schemadoc.sl_table
    						where tab_set = v_row.set_id
    				loop
    					perform schemadoc.alterTableRestore(v_row2.tab_id);
    				end loop;
    			end if;

    			update schemadoc.sl_set set set_origin = p_backup_node
    					where set_id = v_row.set_id;

    			if p_backup_node = schemadoc.getLocalNodeId('_schemadoc') then
    				delete from schemadoc.sl_setsync
    						where ssy_setid = v_row.set_id;

    				for v_row2 in select * from schemadoc.sl_table
    						where tab_set = v_row.set_id
    				loop
    					perform schemadoc.alterTableForReplication(v_row2.tab_id);
    				end loop;
    			end if;

    			delete from schemadoc.sl_subscribe
    					where sub_set = v_row.set_id
    						and sub_receiver = p_backup_node;
    		else
    raise notice 'failedNode: set % has other direct receivers - change providers only', v_row.set_id;
    			-- ----
    			-- Backup node is not the only direct subscriber. This
    			-- means that at this moment, we redirect all direct
    			-- subscribers to receive from the backup node, and the
    			-- backup node itself to receive from another one.
    			-- The admin utility will wait for the slon engine to
    			-- restart and then call failedNode2() on the node with
    			-- the highest SYNC and redirect this to it on
    			-- backup node later.
    			-- ----
    			update schemadoc.sl_subscribe
    					set sub_provider = (select min(SS.sub_receiver)
    							from schemadoc.sl_subscribe SS
    							where SS.sub_set = v_row.set_id
    								and SS.sub_provider = p_failed_node
    								and SS.sub_receiver <> p_backup_node
    								and SS.sub_forward)
    					where sub_set = v_row.set_id
    						and sub_receiver = p_backup_node;
    			update schemadoc.sl_subscribe
    					set sub_provider = p_backup_node
    					where sub_set = v_row.set_id
    						and sub_provider = p_failed_node
    						and sub_receiver <> p_backup_node;
    		end if;
    	end loop;

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	-- ----
    	-- Make sure the node daemon will restart
    	-- ----
    	notify "_schemadoc_Restart";

    	-- ----
    	-- That is it - so far.
    	-- ----
    	return p_failed_node;
    end;

## Function: failednode2( integer, integer, integer, bigint, bigint )

### Returns: bigint

### Language: PLPGSQL

FUNCTION failedNode2 (failed_node, backup_node, set_id, ev_seqno, ev_seqfake) On the node that has the highest sequence number of the failed node, fake the FAILED_NODE event.

    declare
    	p_failed_node		alias for $1;
    	p_backup_node		alias for $2;
    	p_set_id			alias for $3;
    	p_ev_seqno			alias for $4;
    	p_ev_seqfake		alias for $5;
    	v_row				record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	select * into v_row
    			from schemadoc.sl_event
    			where ev_origin = p_failed_node
    			and ev_seqno = p_ev_seqno;
    	if not found then
    		raise exception 'Slony-I: event %,% not found',
    				p_failed_node, p_ev_seqno;
    	end if;

    	insert into schemadoc.sl_event
    			(ev_origin, ev_seqno, ev_timestamp,
    			ev_minxid, ev_maxxid, ev_xip,
    			ev_type, ev_data1, ev_data2, ev_data3)
    			values
    			(p_failed_node, p_ev_seqfake, CURRENT_TIMESTAMP,
    			v_row.ev_minxid, v_row.ev_maxxid, v_row.ev_xip,
    			'FAILOVER_SET', p_failed_node::text, p_backup_node::text,
    			p_set_id::text);
    	insert into schemadoc.sl_confirm
    			(con_origin, con_received, con_seqno, con_timestamp)
    			values
    			(p_failed_node, schemadoc.getLocalNodeId('_schemadoc'),
    			p_ev_seqfake, CURRENT_TIMESTAMP);
    	notify "_schemadoc_Event";
    	notify "_schemadoc_Confirm";
    	notify "_schemadoc_Restart";

    	perform schemadoc.failoverSet_int(p_failed_node,
    			p_backup_node, p_set_id);

    	return p_ev_seqfake;
    end;

## Function: failoverset_int( integer, integer, integer )

### Returns: integer

### Language: PLPGSQL

FUNCTION failoverSet_int (failed_node, backup_node, set_id) Finish failover for one set.

    declare
    	p_failed_node		alias for $1;
    	p_backup_node		alias for $2;
    	p_set_id			alias for $3;
    	v_row				record;
    	v_last_sync			int8;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Change the origin of the set now to the backup node.
    	-- On the backup node this includes changing all the
    	-- trigger and protection stuff
    	-- ----
    	if p_backup_node = schemadoc.getLocalNodeId('_schemadoc') then
    		for v_row in select * from schemadoc.sl_table
    				where tab_set = p_set_id
    		loop
    			perform schemadoc.alterTableRestore(v_row.tab_id);
    		end loop;

    		delete from schemadoc.sl_setsync
    				where ssy_setid = p_set_id;
    		delete from schemadoc.sl_subscribe
    				where sub_set = p_set_id
    					and sub_receiver = p_backup_node;
    		update schemadoc.sl_set
    				set set_origin = p_backup_node
    				where set_id = p_set_id;

    		for v_row in select * from schemadoc.sl_table
    				where tab_set = p_set_id
    		loop
    			perform schemadoc.alterTableForReplication(v_row.tab_id);
    		end loop;
    	else
    		delete from schemadoc.sl_subscribe
    				where sub_set = p_set_id
    					and sub_receiver = p_backup_node;
    		update schemadoc.sl_set
    				set set_origin = p_backup_node
    				where set_id = p_set_id;
    	end if;

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	-- ----
    	-- If we are a subscriber of the set ourself, change our
    	-- setsync status to reflect the new set origin.
    	-- ----
    	if exists (select true from schemadoc.sl_subscribe
    			where sub_set = p_set_id
    				and sub_receiver = schemadoc.getLocalNodeId(
    						'_schemadoc'))
    	then
    		delete from schemadoc.sl_setsync
    				where ssy_setid = p_set_id;

    		select coalesce(max(ev_seqno), 0) into v_last_sync
    				from schemadoc.sl_event
    				where ev_origin = p_backup_node
    					and ev_type = 'SYNC';
    		if v_last_sync > 0 then
    			insert into schemadoc.sl_setsync
    					(ssy_setid, ssy_origin, ssy_seqno,
    					ssy_minxid, ssy_maxxid, ssy_xip, ssy_action_list)
    					select p_set_id, p_backup_node, v_last_sync,
    					ev_minxid, ev_maxxid, ev_xip, NULL
    					from schemadoc.sl_event
    					where ev_origin = p_backup_node
    						and ev_seqno = v_last_sync;
    		else
    			insert into schemadoc.sl_setsync
    					(ssy_setid, ssy_origin, ssy_seqno,
    					ssy_minxid, ssy_maxxid, ssy_xip, ssy_action_list)
    					values (p_set_id, p_backup_node, '0',
    					'0', '0', '', NULL);
    		end if;

    	end if;

    	return p_failed_node;
    end;

## Function: forwardconfirm( integer, integer, bigint, timestamp without time zone )

### Returns: bigint

### Language: PLPGSQL

forwardConfirm (p_con_origin, p_con_received, p_con_seqno, p_con_timestamp) Confirms (recorded in sl_confirm) that items from p_con_origin up to p_con_seqno have been received by node p_con_received as of p_con_timestamp, and raises an event to forward this confirmation.

    declare
    	p_con_origin	alias for $1;
    	p_con_received	alias for $2;
    	p_con_seqno		alias for $3;
    	p_con_timestamp	alias for $4;
    	v_max_seqno		bigint;
    begin
    	select into v_max_seqno coalesce(max(con_seqno), 0)
    			from schemadoc.sl_confirm
    			where con_origin = p_con_origin
    			and con_received = p_con_received;
    	if v_max_seqno < p_con_seqno then
    		insert into schemadoc.sl_confirm
    				(con_origin, con_received, con_seqno, con_timestamp)
    				values (p_con_origin, p_con_received, p_con_seqno,
    					p_con_timestamp);
    		notify "_schemadoc_Confirm";
    		v_max_seqno = p_con_seqno;
    	end if;

    	return v_max_seqno;
    end;

## Function: getlocalnodeid( name )

### Returns: integer

### Language: C

Returns the node ID of the node being serviced on the local database

    _Slony_I_getLocalNodeId

## Function: getmoduleversion( )

### Returns: text

### Language: C

Returns the compiled-in version number of the Slony-I shared object

    _Slony_I_getModuleVersion

## Function: getsessionrole( name )

### Returns: text

### Language: C

not yet documented

    _Slony_I_getSessionRole

## Function: initializelocalnode( integer, text )

### Returns: integer

### Language: PLPGSQL

no_id - Node ID # no_comment - Human-oriented comment Initializes the new node, no_id

    declare
    	p_local_node_id		alias for $1;
    	p_comment			alias for $2;
    	v_old_node_id		int4;
    	v_first_log_no		int4;
    	v_event_seq			int8;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Make sure this node is uninitialized or got reset
    	-- ----
    	select last_value::int4 into v_old_node_id from schemadoc.sl_local_node_id;
    	if v_old_node_id != -1 then
    		raise exception 'Slony-I: This node is already initialized';
    	end if;

    	-- ----
    	-- Set sl_local_node_id to the requested value and add our
    	-- own system to sl_node.
    	-- ----
    	perform setval('schemadoc.sl_local_node_id', p_local_node_id);
    	perform setval('schemadoc.sl_rowid_seq',
    			p_local_node_id::int8 * '1000000000000000'::int8);
    	perform schemadoc.storeNode_int (p_local_node_id, p_comment);

    	return p_local_node_id;
    end;

## Function: lockedset( )

### Returns: "trigger"

### Language: C

Trigger function to prevent modifications to a table before and after a moveSet()

    _Slony_I_lockedSet

## Function: lockset( integer )

### Returns: integer

### Language: PLPGSQL

lockSet(set_id) Add a special trigger to all tables of a set that disables access to it.

    declare
    	p_set_id			alias for $1;
    	v_local_node_id		int4;
    	v_set_row			record;
    	v_tab_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that the set exists and that we are the origin
    	-- and that it is not already locked.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select * into v_set_row from schemadoc.sl_set
    			where set_id = p_set_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_set_row.set_origin <> v_local_node_id then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_set_id;
    	end if;
    	if v_set_row.set_locked notnull then
    		raise exception 'Slony-I: set % is already locked', p_set_id;
    	end if;

    	-- ----
    	-- Place the lockedSet trigger on all tables in the set.
    	-- ----
    	for v_tab_row in select T.tab_id,
    			"pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			"pg_catalog".quote_ident(PGC.relname) as tab_fqname
    			from schemadoc.sl_table T,
    				"pg_catalog".pg_class PGC, "pg_catalog".pg_namespace PGN
    			where T.tab_set = p_set_id
    				and T.tab_reloid = PGC.oid
    				and PGC.relnamespace = PGN.oid
    			order by tab_id
    	loop
    		execute 'create trigger "_schemadoc_lockedset_' ||
    				v_tab_row.tab_id ||
    				'" before insert or update or delete on ' ||
    				v_tab_row.tab_fqname || ' for each row execute procedure
    				schemadoc.lockedSet (''_schemadoc'');';
    	end loop;

    	-- ----
    	-- Remember our snapshots xmax as for the set locking
    	-- ----
    	update schemadoc.sl_set
    			set set_locked = schemadoc.getMaxXid()
    			where set_id = p_set_id;

    	return p_set_id;
    end;

## Function: logtrigger( )

### Returns: "trigger"

### Language: C

This is the trigger that is executed on the origin node that causes updates to be recorded in sl_log_1/sl_log_2.

    _Slony_I_logTrigger

## Function: mergeset( integer, integer )

### Returns: bigint

### Language: PLPGSQL

Generate MERGE_SET event to request that sets be merged together. Both sets must exist, and originate on the same node. They must be subscribed by the same set of nodes.

    declare
    	p_set_id			alias for $1;
    	p_add_id			alias for $2;
    	v_origin			int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that both sets exist and originate here
    	-- ----
    	if p_set_id = p_add_id then
    		raise exception 'Slony-I: merged set ids cannot be identical';
    	end if;
    	select set_origin into v_origin from schemadoc.sl_set
    			where set_id = p_set_id;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_set_id;
    	end if;

    	select set_origin into v_origin from schemadoc.sl_set
    			where set_id = p_add_id;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_add_id;
    	end if;
    	if v_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_add_id;
    	end if;

    	-- ----
    	-- Check that both sets are subscribed by the same set of nodes
    	-- ----
    	if exists (select true from schemadoc.sl_subscribe SUB1
    				where SUB1.sub_set = p_set_id
    				and SUB1.sub_receiver not in (select SUB2.sub_receiver
    						from schemadoc.sl_subscribe SUB2
    						where SUB2.sub_set = p_add_id))
    	then
    		raise exception 'Slony-I: subscriber lists of set % and % are different',
    				p_set_id, p_add_id;
    	end if;

    	if exists (select true from schemadoc.sl_subscribe SUB1
    				where SUB1.sub_set = p_add_id
    				and SUB1.sub_receiver not in (select SUB2.sub_receiver
    						from schemadoc.sl_subscribe SUB2
    						where SUB2.sub_set = p_set_id))
    	then
    		raise exception 'Slony-I: subscriber lists of set % and % are different',
    				p_add_id, p_set_id;
    	end if;

    	-- ----
    	-- Create a SYNC event, merge the sets, create a MERGE_SET event
    	-- ----
    	perform schemadoc.createEvent('_schemadoc', 'SYNC', NULL);
    	perform schemadoc.mergeSet_int(p_set_id, p_add_id);
    	return  schemadoc.createEvent('_schemadoc', 'MERGE_SET',
    			p_set_id, p_add_id);
    end;

## Function: mergeset_int( integer, integer )

### Returns: integer

### Language: PLPGSQL

mergeSet_int(set_id, add_id) - Perform MERGE_SET event, merging all objects from set add_id into set set_id.

    declare
    	p_set_id			alias for $1;
    	p_add_id			alias for $2;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	update schemadoc.sl_sequence
    			set seq_set = p_set_id
    			where seq_set = p_add_id;
    	update schemadoc.sl_table
    			set tab_set = p_set_id
    			where tab_set = p_add_id;
    	delete from schemadoc.sl_subscribe
    			where sub_set = p_add_id;
    	delete from schemadoc.sl_setsync
    			where ssy_setid = p_add_id;
    	delete from schemadoc.sl_set
    			where set_id = p_add_id;

    	return p_set_id;
    end;

## Function: moveset( integer, integer )

### Returns: bigint

### Language: PLPGSQL

moveSet(set_id, new_origin) Generate MOVE_SET event to request that the origin for set set_id be moved to node new_origin

    declare
    	p_set_id			alias for $1;
    	p_new_origin		alias for $2;
    	v_local_node_id		int4;
    	v_set_row			record;
    	v_sub_row			record;
    	v_sync_seqno		int8;
    	v_lv_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that the set is locked and that this locking
    	-- happened long enough ago.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select * into v_set_row from schemadoc.sl_set
    			where set_id = p_set_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_set_row.set_origin <> v_local_node_id then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_set_id;
    	end if;
    	if v_set_row.set_locked isnull then
    		raise exception 'Slony-I: set % is not locked', p_set_id;
    	end if;
    	if v_set_row.set_locked > schemadoc.getMinXid() then
    		raise exception 'Slony-I: cannot move set % yet, transactions < % are still in progress',
    				p_set_id, v_set_row.set_locked;
    	end if;

    	-- ----
    	-- Unlock the set
    	-- ----
    	perform schemadoc.unlockSet(p_set_id);

    	-- ----
    	-- Check that the new_origin is an active subscriber of the set
    	-- ----
    	select * into v_sub_row from schemadoc.sl_subscribe
    			where sub_set = p_set_id
    			and sub_receiver = p_new_origin;
    	if not found then
    		raise exception 'Slony-I: set % is not subscribed by node %',
    				p_set_id, p_new_origin;
    	end if;
    	if not v_sub_row.sub_active then
    		raise exception 'Slony-I: subsctiption of node % for set % is inactive',
    				p_new_origin, p_set_id;
    	end if;

    	-- ----
    	-- Reconfigure everything
    	-- ----
    	perform schemadoc.moveSet_int(p_set_id, v_local_node_id,
    			p_new_origin);

    	for v_sub_row in select sub_provider, sub_receiver
    			from schemadoc.sl_subscribe
    			where sub_set = p_set_id
    	loop
    		perform schemadoc.GenerateListensOnSubscribe(v_sub_row.sub_provider, v_sub_row.sub_receiver)
    	done;

    	-- ----
    	-- At this time we hold access exclusive locks for every table
    	-- in the set. But we did move the set to the new origin, so the
    	-- createEvent() we are doing now will not record the sequences.
    	-- ----
    	v_sync_seqno := schemadoc.createEvent('_schemadoc', 'SYNC');
    	insert into schemadoc.sl_seqlog
    			(seql_seqid, seql_origin, seql_ev_seqno, seql_last_value)
    			select seq_id, v_local_node_id, v_sync_seqno, seq_last_value
    			from schemadoc.sl_seqlastvalue
    			where seq_set = p_set_id;

    	-- ----
    	-- Finally we generate the real event
    	-- ----
    	return schemadoc.createEvent('_schemadoc', 'MOVE_SET',
    			p_set_id, v_local_node_id, p_new_origin);
    end;

## Function: moveset_int( integer, integer, integer )

### Returns: integer

### Language: PLPGSQL

moveSet(set_id, old_origin, new_origin) Process MOVE_SET event to request that the origin for set set_id be moved from old_origin to node new_origin

    declare
    	p_set_id			alias for $1;
    	p_old_origin		alias for $2;
    	p_new_origin		alias for $3;
    	v_local_node_id		int4;
    	v_tab_row			record;
    	v_sub_row			record;
    	v_sub_node			int4;
    	v_sub_last			int4;
    	v_sub_next			int4;
    	v_last_sync			int8;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Get our local node ID
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');

    	-- ----
    	-- If we are the old or new origin of the set, we need to
    	-- remove the log trigger from all tables first.
    	-- ----
    	if v_local_node_id = p_old_origin or v_local_node_id = p_new_origin then
    		for v_tab_row in select tab_id from schemadoc.sl_table
    				where tab_set = p_set_id
    				order by tab_id
    		loop
    			perform schemadoc.alterTableRestore(v_tab_row.tab_id);
    		end loop;
    	end if;

    	-- ----
    	-- Next we have to reverse the subscription path
    	-- ----
    	v_sub_last = p_new_origin;
    	select sub_provider into v_sub_node
    			from schemadoc.sl_subscribe
    			where sub_receiver = p_new_origin;
    	if not found then
    		raise exception 'Slony-I: subscription path broken in moveSet_int';
    	end if;
    	while v_sub_node <> p_old_origin loop
    		-- ----
    		-- Tracing node by node, the old receiver is now in
    		-- v_sub_last and the old provider is in v_sub_node.
    		-- ----

    		-- ----
    		-- Get the current provider of this node as next
    		-- and change the provider to the previous one in
    		-- the reverse chain.
    		-- ----
    		select sub_provider into v_sub_next
    				from schemadoc.sl_subscribe
    				where sub_set = p_set_id
    					and sub_receiver = v_sub_node
    				for update;
    		if not found then
    			raise exception 'Slony-I: subscription path broken in moveSet_int';
    		end if;
    		update schemadoc.sl_subscribe
    				set sub_provider = v_sub_last
    				where sub_set = p_set_id
    					and sub_receiver = v_sub_node;

    		v_sub_last = v_sub_node;
    		v_sub_node = v_sub_next;
    	end loop;

    	-- ----
    	-- This includes creating a subscription for the old origin
    	-- ----
    	insert into schemadoc.sl_subscribe
    			(sub_set, sub_provider, sub_receiver,
    			sub_forward, sub_active)
    			values (p_set_id, v_sub_last, p_old_origin, true, true);
    	if v_local_node_id = p_old_origin then
    		select coalesce(max(ev_seqno), 0) into v_last_sync
    				from schemadoc.sl_event
    				where ev_origin = p_new_origin
    					and ev_type = 'SYNC';
    		if v_last_sync > 0 then
    			insert into schemadoc.sl_setsync
    					(ssy_setid, ssy_origin, ssy_seqno,
    					ssy_minxid, ssy_maxxid, ssy_xip, ssy_action_list)
    					select p_set_id, p_new_origin, v_last_sync,
    					ev_minxid, ev_maxxid, ev_xip, NULL
    					from schemadoc.sl_event
    					where ev_origin = p_new_origin
    						and ev_seqno = v_last_sync;
    		else
    			insert into schemadoc.sl_setsync
    					(ssy_setid, ssy_origin, ssy_seqno,
    					ssy_minxid, ssy_maxxid, ssy_xip, ssy_action_list)
    					values (p_set_id, p_new_origin, '0',
    					'0', '0', '', NULL);
    		end if;
    	end if;

    	-- ----
    	-- Now change the ownership of the set.
    	-- ----
    	update schemadoc.sl_set
    			set set_origin = p_new_origin
    			where set_id = p_set_id;

    	-- ----
    	-- On the new origin, delete the obsolete setsync information
    	-- and the subscription.
    	-- ----
    	if v_local_node_id = p_new_origin then
    		delete from schemadoc.sl_setsync
    				where ssy_setid = p_set_id;
    	else
    		if v_local_node_id <> p_old_origin then
    			--
    			-- On every other node, change the setsync so that it will
    			-- pick up from the new origins last known sync.
    			--
    			delete from schemadoc.sl_setsync
    					where ssy_setid = p_set_id;
    			select coalesce(max(ev_seqno), 0) into v_last_sync
    					from schemadoc.sl_event
    					where ev_origin = p_new_origin
    						and ev_type = 'SYNC';
    			if v_last_sync > 0 then
    				insert into schemadoc.sl_setsync
    						(ssy_setid, ssy_origin, ssy_seqno,
    						ssy_minxid, ssy_maxxid, ssy_xip, ssy_action_list)
    						select p_set_id, p_new_origin, v_last_sync,
    						ev_minxid, ev_maxxid, ev_xip, NULL
    						from schemadoc.sl_event
    						where ev_origin = p_new_origin
    							and ev_seqno = v_last_sync;
    			else
    				insert into schemadoc.sl_setsync
    						(ssy_setid, ssy_origin, ssy_seqno,
    						ssy_minxid, ssy_maxxid, ssy_xip, ssy_action_list)
    						values (p_set_id, p_new_origin, '0',
    						'0', '0', '', NULL);
    			end if;
    		end if;
    	end if;
    	delete from schemadoc.sl_subscribe
    			where sub_set = p_set_id
    			and sub_receiver = p_new_origin;

    	-- Regenerate sl_listen since we revised the subscriptions
    	perform schemadoc.RebuildListenEntries();

    	-- ----
    	-- If we are the new or old origin, we have to
    	-- put all the tables into altered state again.
    	-- ----
    	if v_local_node_id = p_old_origin or v_local_node_id = p_new_origin then
    		for v_tab_row in select tab_id from schemadoc.sl_table
    				where tab_set = p_set_id
    				order by tab_id
    		loop
    			perform schemadoc.alterTableForReplication(v_tab_row.tab_id);
    		end loop;
    	end if;

    	return p_set_id;
    end;

## Function: rebuildlistenentries( )

### Returns: integer

### Language: PLPGSQL

RebuildListenEntries(p_provider, p_receiver) Invoked by various subscription and path modifying functions, this rewrites the sl_listen entries, adding in all the ones required to allow communications between nodes in the Slony-I cluster.

    declare
    	v_row			record;
    	v_row2			record;
    	v_row3			record;
    	v_origin		int4;
    	v_receiver		int4;
    	v_done			boolean;

    begin
    	-- 0.  Drop out listens
    	delete from schemadoc.sl_listen;

    	-- 1.  Add listens pointed out by subscriptions - sl_listen
    	select schemadoc.storelisten(sub_provider, sub_provider, sub_receiver)
    		from schemadoc.sl_subscribe;

    	-- 2.  Add direct listens pointed out in sl_path
    	select schemadoc.storelisten(pa_server, pa_server, pa_client)
    		from schemadoc.sl_path path
    		where not exists (select true from schemadoc.sl_listen listen
    					where path.pa_server = listen.li_origin and
    					      path.pa_client = listen.li_reciever);

    	-- 3.  Iterate until we cannot iterate any more...
    	--     Add in indirect listens based on what is in sl_listen and sl_path
    	v_done := 'f';
    	while not v_done loop
    		select schemadoc.storelisten(li_origin,pa_server,pa_client)
    			from schemadoc.sl_path path, schemadoc.sl_listen listen
    			where
    				li_reciever = pa_server
    				and not exists (select true from schemadoc.sl_listen listen2
    					where listen2.li_origin = listen.origin and
    					      listen2.li_reciever = path.pa_client);

    	end loop;
    end;

## Function: sequencelastvalue( text )

### Returns: bigint

### Language: PLPGSQL

    declare
    	p_seqname	alias for $1;
    	v_seq_row	record;
    begin
    	for v_seq_row in execute 'select last_value from ' || p_seqname
    	loop
    		return v_seq_row.last_value;
    	end loop;

    	-- not reached
    end;

## Function: sequencesetvalue( integer, integer, bigint, bigint )

### Returns: integer

### Language: PLPGSQL

sequenceSetValue (seq_id, seq_origin, ev_seqno, last_value) Set sequence seq_id to have new value last_value.

    declare
    	p_seq_id			alias for $1;
    	p_seq_origin		alias for $2;
    	p_ev_seqno			alias for $3;
    	p_last_value		alias for $4;
    	v_fqname			text;
    begin
    	-- ----
    	-- Get the sequences fully qualified name
    	-- ----
    	select "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			"pg_catalog".quote_ident(PGC.relname) into v_fqname
    		from schemadoc.sl_sequence SQ,
    			"pg_catalog".pg_class PGC, "pg_catalog".pg_namespace PGN
    		where SQ.seq_id = p_seq_id
    			and SQ.seq_reloid = PGC.oid
    			and PGC.relnamespace = PGN.oid;
    	if not found then
    		raise exception 'Slony-I: sequence % not found', p_seq_id;
    	end if;

    	-- ----
    	-- Update it to the new value
    	-- ----
    	execute 'select setval(''' || v_fqname ||
    			''', ''' || p_last_value || ''')';

    	insert into schemadoc.sl_seqlog
    			(seql_seqid, seql_origin, seql_ev_seqno, seql_last_value)
    			values (p_seq_id, p_seq_origin, p_ev_seqno, p_last_value);

    	return p_seq_id;
    end;

## Function: setaddsequence( integer, integer, text, text )

### Returns: bigint

### Language: PLPGSQL

setAddSequence (set_id, seq_id, seq_fqname, seq_comment) On the origin node for set set_id, add sequence seq_fqname to the replication set, and raise SET_ADD_SEQUENCE to cause this to replicate to subscriber nodes.

    declare
    	p_set_id			alias for $1;
    	p_seq_id			alias for $2;
    	p_fqname			alias for $3;
    	p_seq_comment		alias for $4;
    	v_set_origin		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that we are the origin of the set
    	-- ----
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_set_id;
    	if not found then
    		raise exception 'Slony-I: setAddSequence(): set % not found', p_set_id;
    	end if;
    	if v_set_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: setAddSequence(): set % has remote origin', p_set_id;
    	end if;

    	if exists (select true from schemadoc.sl_subscribe
    			where sub_set = p_set_id)
    	then
    		raise exception 'Slony-I: cannot add sequence to currently subscribed set %',
    				p_set_id;
    	end if;

    	-- ----
    	-- Add the sequence to the set and generate the SET_ADD_SEQUENCE event
    	-- ----
    	perform schemadoc.setAddSequence_int(p_set_id, p_seq_id, p_fqname,
    			p_seq_comment);
    	return  schemadoc.createEvent('_schemadoc', 'SET_ADD_SEQUENCE',
    			p_set_id, p_seq_id, p_fqname, p_seq_comment);
    end;

## Function: setaddsequence_int( integer, integer, text, text )

### Returns: integer

### Language: PLPGSQL

setAddSequence_int (set_id, seq_id, seq_fqname, seq_comment) This processes the SET_ADD_SEQUENCE event. On remote nodes that subscribe to set_id, add the sequence to the replication set.

    declare
    	p_set_id			alias for $1;
    	p_seq_id			alias for $2;
    	p_fqname			alias for $3;
    	p_seq_comment		alias for $4;
    	v_local_node_id		int4;
    	v_set_origin		int4;
    	v_sub_provider		int4;
    	v_relkind			char;
    	v_seq_reloid		oid;
    	v_sync_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- For sets with a remote origin, check that we are subscribed
    	-- to that set. Otherwise we ignore the sequence because it might
    	-- not even exist in our database.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_set_id;
    	if not found then
    		raise exception 'Slony-I: setAddSequence_int(): set % not found',
    				p_set_id;
    	end if;
    	if v_set_origin != v_local_node_id then
    		select sub_provider into v_sub_provider
    				from schemadoc.sl_subscribe
    				where sub_set = p_set_id
    				and sub_receiver = schemadoc.getLocalNodeId('_schemadoc');
    		if not found then
    			return 0;
    		end if;
    	end if;

    	-- ----
    	-- Get the sequences OID and check that it is a sequence
    	-- ----
    	select PGC.oid, PGC.relkind into v_seq_reloid, v_relkind
    			from "pg_catalog".pg_class PGC, "pg_catalog".pg_namespace PGN
    			where PGC.relnamespace = PGN.oid
    			and p_fqname = "pg_catalog".quote_ident(PGN.nspname) ||
    					'.' || "pg_catalog".quote_ident(PGC.relname);
    	if not found then
    		raise exception 'Slony-I: setAddSequence_int(): sequence % not found',
    				p_fqname;
    	end if;
    	if v_relkind != 'S' then
    		raise exception 'Slony-I: setAddSequence_int(): % is not a sequence',
    				p_fqname;
    	end if;

    	-- ----
    	-- Add the sequence to sl_sequence
    	-- ----
    	insert into schemadoc.sl_sequence
    			(seq_id, seq_reloid, seq_set, seq_comment) values
    			(p_seq_id, v_seq_reloid, p_set_id, p_seq_comment);

    	-- ----
    	-- On the set origin, fake a sl_seqlog row for the last sync event
    	-- ----
    	if v_set_origin = v_local_node_id then
    		for v_sync_row in select coalesce (max(ev_seqno), 0) as ev_seqno
    				from schemadoc.sl_event
    				where ev_origin = v_local_node_id
    					and ev_type = 'SYNC'
    		loop
    			insert into schemadoc.sl_seqlog
    					(seql_seqid, seql_origin, seql_ev_seqno,
    					seql_last_value) values
    					(p_seq_id, v_local_node_id, v_sync_row.ev_seqno,
    					schemadoc.sequenceLastValue(p_fqname));
    		end loop;
    	end if;

    	return p_seq_id;
    end;

## Function: setaddtable( integer, integer, text, name, text )

### Returns: bigint

### Language: PLPGSQL

setAddTable (set_id, tab_id, tab_fqname, tab_idxname, tab_comment) Add table tab_fqname to replication set on origin node, and generate SET_ADD_TABLE event to allow this to propagate to other nodes. Note that the table id, tab_id, must be unique ACROSS ALL SETS.

    declare
    	p_set_id			alias for $1;
    	p_tab_id			alias for $2;
    	p_fqname			alias for $3;
    	p_tab_idxname		alias for $4;
    	p_tab_comment		alias for $5;
    	v_set_origin		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that we are the origin of the set
    	-- ----
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_set_id;
    	if not found then
    		raise exception 'Slony-I: setAddTable(): set % not found', p_set_id;
    	end if;
    	if v_set_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: setAddTable(): set % has remote origin', p_set_id;
    	end if;

    	if exists (select true from schemadoc.sl_subscribe
    			where sub_set = p_set_id)
    	then
    		raise exception 'Slony-I: cannot add table to currently subscribed set %',
    				p_set_id;
    	end if;

    	-- ----
    	-- Add the table to the set and generate the SET_ADD_TABLE event
    	-- ----
    	perform schemadoc.setAddTable_int(p_set_id, p_tab_id, p_fqname,
    			p_tab_idxname, p_tab_comment);
    	return  schemadoc.createEvent('_schemadoc', 'SET_ADD_TABLE',
    			p_set_id, p_tab_id, p_fqname,
    			p_tab_idxname, p_tab_comment);
    end;

## Function: setaddtable_int( integer, integer, text, name, text )

### Returns: integer

### Language: PLPGSQL

setAddTable_int (set_id, tab_id, tab_fqname, tab_idxname, tab_comment) This function processes the SET_ADD_TABLE event on remote nodes, adding a table to replication if the remote node is subscribing to its replication set.

    declare
    	p_set_id			alias for $1;
    	p_tab_id			alias for $2;
    	p_fqname			alias for $3;
    	p_tab_idxname		alias for $4;
    	p_tab_comment		alias for $5;
    	v_local_node_id		int4;
    	v_set_origin		int4;
    	v_sub_provider		int4;
    	v_relkind			char;
    	v_tab_reloid		oid;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- For sets with a remote origin, check that we are subscribed
    	-- to that set. Otherwise we ignore the table because it might
    	-- not even exist in our database.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_set_id;
    	if not found then
    		raise exception 'Slony-I: setAddTable_int(): set % not found',
    				p_set_id;
    	end if;
    	if v_set_origin != v_local_node_id then
    		select sub_provider into v_sub_provider
    				from schemadoc.sl_subscribe
    				where sub_set = p_set_id
    				and sub_receiver = schemadoc.getLocalNodeId('_schemadoc');
    		if not found then
    			return 0;
    		end if;
    	end if;

    	-- ----
    	-- Get the tables OID and check that it is a real table
    	-- ----
    	select PGC.oid, PGC.relkind into v_tab_reloid, v_relkind
    			from "pg_catalog".pg_class PGC, "pg_catalog".pg_namespace PGN
    			where PGC.relnamespace = PGN.oid
    			and p_fqname = "pg_catalog".quote_ident(PGN.nspname) ||
    					'.' || "pg_catalog".quote_ident(PGC.relname);
    	if not found then
    		raise exception 'Slony-I: setAddTable(): table % not found',
    				p_fqname;
    	end if;
    	if v_relkind != 'r' then
    		raise exception 'Slony-I: setAddTable(): % is not a regular table',
    				p_fqname;
    	end if;

    	if not exists (select indexrelid
    			from "pg_catalog".pg_index PGX, "pg_catalog".pg_class PGC
    			where PGX.indrelid = v_tab_reloid
    				and PGX.indexrelid = PGC.oid
    				and PGC.relname = p_tab_idxname)
    	then
    		raise exception 'Slony-I: setAddTable(): table % has no index %',
    				p_fqname, p_tab_idxname;
    	end if;

    	-- ----
    	-- Add the table to sl_table and create the trigger on it.
    	-- ----
    	insert into schemadoc.sl_table
    			(tab_id, tab_reloid, tab_set, tab_idxname,
    			tab_altered, tab_comment) values
    			(p_tab_id, v_tab_reloid, p_set_id, p_tab_idxname,
    			false, p_tab_comment);
    	perform schemadoc.alterTableForReplication(p_tab_id);

    	return p_tab_id;
    end;

## Function: setdropsequence( integer )

### Returns: bigint

### Language: PLPGSQL

setDropSequence (seq_id) On the origin node for the set, drop sequence seq_id from replication set, and raise SET_DROP_SEQUENCE to cause this to replicate to subscriber nodes.

    declare
    	p_seq_id		alias for $1;
    	v_set_id		int4;
    	v_set_origin		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Determine set id for this sequence
    	-- ----
    	select seq_set into v_set_id from schemadoc.sl_sequence where seq_id = p_seq_id;

    	-- ----
    	-- Ensure sequence exists
    	-- ----
    	if not found then
    		raise exception 'Slony-I: setDropSequence_int(): sequence % not found',
    			p_seq_id;
    	end if;

    	-- ----
    	-- Check that we are the origin of the set
    	-- ----
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = v_set_id;
    	if not found then
    		raise exception 'Slony-I: setDropSequence(): set % not found', v_set_id;
    	end if;
    	if v_set_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: setDropSequence(): set % has remote origin', v_set_id;
    	end if;

    	-- ----
    	-- Add the sequence to the set and generate the SET_ADD_SEQUENCE event
    	-- ----
    	perform schemadoc.setDropSequence_int(p_seq_id);
    	return  schemadoc.createEvent('_schemadoc', 'SET_DROP_SEQUENCE',
    			p_seq_id);
    end;

## Function: setdropsequence_int( integer )

### Returns: integer

### Language: PLPGSQL

setDropSequence_int (seq_id) This processes the SET_DROP_SEQUENCE event. On remote nodes that subscribe to the set containing sequence seq_id, drop the sequence from the replication set.

    declare
    	p_seq_id		alias for $1;
    	v_set_id		int4;
    	v_local_node_id		int4;
    	v_set_origin		int4;
    	v_sub_provider		int4;
    	v_relkind			char;
    	v_sync_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Determine set id for this sequence
    	-- ----
    	select seq_set into v_set_id from schemadoc.sl_sequence where seq_id = p_seq_id;

    	-- ----
    	-- Ensure sequence exists
    	-- ----
    	if not found then
    		return 0;
    	end if;

    	-- ----
    	-- For sets with a remote origin, check that we are subscribed
    	-- to that set. Otherwise we ignore the sequence because it might
    	-- not even exist in our database.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = v_set_id;
    	if not found then
    		raise exception 'Slony-I: setDropSequence_int(): set % not found',
    				v_set_id;
    	end if;
    	if v_set_origin != v_local_node_id then
    		select sub_provider into v_sub_provider
    				from schemadoc.sl_subscribe
    				where sub_set = v_set_id
    				and sub_receiver = schemadoc.getLocalNodeId('_schemadoc');
    		if not found then
    			return 0;
    		end if;
    	end if;

    	-- ----
    	-- drop the sequence from sl_sequence, sl_seqlog
    	-- ----
    	delete from schemadoc.sl_seqlog where seql_seqid = p_seq_id;
    	delete from schemadoc.sl_sequence where seq_id = p_seq_id;

    	return p_seq_id;
    end;

## Function: setdroptable( integer )

### Returns: bigint

### Language: PLPGSQL

setDropTable (tab_id) Drop table tab_id from set on origin node, and generate SET_DROP_TABLE event to allow this to propagate to other nodes.

    declare
    	p_tab_id		alias for $1;
    	v_set_id		int4;
    	v_set_origin		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

            -- ----
    	-- Determine the set_id
            -- ----
    	select tab_set into v_set_id from schemadoc.sl_table where tab_id = p_tab_id;

    	-- ----
    	-- Ensure table exists
    	-- ----
    	if not found then
    		raise exception 'Slony-I: setDropTable_int(): table % not found',
    			p_tab_id;
    	end if;

    	-- ----
    	-- Check that we are the origin of the set
    	-- ----
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = v_set_id;
    	if not found then
    		raise exception 'Slony-I: setDropTable(): set % not found', v_set_id;
    	end if;
    	if v_set_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: setDropTable(): set % has remote origin', v_set_id;
    	end if;

    	-- ----
    	-- Drop the table from the set and generate the SET_ADD_TABLE event
    	-- ----
    	perform schemadoc.setDropTable_int(p_tab_id);
    	return  schemadoc.createEvent('_schemadoc', 'SET_DROP_TABLE', p_tab_id);
    end;

## Function: setdroptable_int( integer )

### Returns: integer

### Language: PLPGSQL

setDropTable_int (tab_id) This function processes the SET_DROP_TABLE event on remote nodes, dropping a table from replication if the remote node is subscribing to its replication set.

    declare
    	p_tab_id		alias for $1;
    	v_set_id		int4;
    	v_local_node_id		int4;
    	v_set_origin		int4;
    	v_sub_provider		int4;
    	v_tab_reloid		oid;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

            -- ----
    	-- Determine the set_id
            -- ----
    	select tab_set into v_set_id from schemadoc.sl_table where tab_id = p_tab_id;

    	-- ----
    	-- Ensure table exists
    	-- ----
    	if not found then
    		return 0;
    	end if;

    	-- ----
    	-- For sets with a remote origin, check that we are subscribed
    	-- to that set. Otherwise we ignore the table because it might
    	-- not even exist in our database.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = v_set_id;
    	if not found then
    		raise exception 'Slony-I: setDropTable_int(): set % not found',
    				v_set_id;
    	end if;
    	if v_set_origin != v_local_node_id then
    		select sub_provider into v_sub_provider
    				from schemadoc.sl_subscribe
    				where sub_set = v_set_id
    				and sub_receiver = schemadoc.getLocalNodeId('_schemadoc');
    		if not found then
    			return 0;
    		end if;
    	end if;

    	-- ----
    	-- Drop the table from sl_table and drop trigger from it.
    	-- ----
    	perform schemadoc.alterTableRestore(p_tab_id);
    	perform schemadoc.tableDropKey(p_tab_id);
    	delete from schemadoc.sl_table where tab_id = p_tab_id;
    	return p_tab_id;
    end;

## Function: setmovesequence( integer, integer )

### Returns: bigint

### Language: PLPGSQL

    declare
    	p_seq_id			alias for $1;
    	p_new_set_id		alias for $2;
    	v_old_set_id		int4;
    	v_origin			int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Get the sequences current set
    	-- ----
    	select seq_set into v_old_set_id from schemadoc.sl_sequence
    			where seq_id = p_seq_id;
    	if not found then
    		raise exception 'Slony-I: sequence %d not found', p_seq_id;
    	end if;

    	-- ----
    	-- Check that both sets exist and originate here
    	-- ----
    	if p_new_set_id = v_old_set_id then
    		raise exception 'Slony-I: set ids cannot be identical';
    	end if;
    	select set_origin into v_origin from schemadoc.sl_set
    			where set_id = p_new_set_id;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_new_set_id;
    	end if;
    	if v_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_new_set_id;
    	end if;

    	select set_origin into v_origin from schemadoc.sl_set
    			where set_id = v_old_set_id;
    	if not found then
    		raise exception 'Slony-I: set % not found', v_old_set_id;
    	end if;
    	if v_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				v_old_set_id;
    	end if;

    	-- ----
    	-- Check that both sets are subscribed by the same set of nodes
    	-- ----
    	if exists (select true from schemadoc.sl_subscribe SUB1
    				where SUB1.sub_set = p_new_set_id
    				and SUB1.sub_receiver not in (select SUB2.sub_receiver
    						from schemadoc.sl_subscribe SUB2
    						where SUB2.sub_set = v_old_set_id))
    	then
    		raise exception 'Slony-I: subscriber lists of set % and % are different',
    				p_new_set_id, v_old_set_id;
    	end if;

    	if exists (select true from schemadoc.sl_subscribe SUB1
    				where SUB1.sub_set = v_old_set_id
    				and SUB1.sub_receiver not in (select SUB2.sub_receiver
    						from schemadoc.sl_subscribe SUB2
    						where SUB2.sub_set = p_new_set_id))
    	then
    		raise exception 'Slony-I: subscriber lists of set % and % are different',
    				v_old_set_id, p_new_set_id;
    	end if;

    	-- ----
    	-- Change the set the sequence belongs to
    	-- ----
    	perform schemadoc.setMoveSequence_int(p_seq_id, p_new_set_id);
    	return  schemadoc.createEvent('_schemadoc', 'SET_MOVE_SEQUENCE',
    			p_seq_id, p_new_set_id);
    end;

## Function: setmovesequence_int( integer, integer )

### Returns: integer

### Language: PLPGSQL

    declare
    	p_seq_id			alias for $1;
    	p_new_set_id		alias for $2;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Move the sequence to the new set
    	-- ----
    	update schemadoc.sl_sequence
    			set seq_set = p_new_set_id
    			where seq_id = p_seq_id;

    	return p_seq_id;
    end;

## Function: setmovetable( integer, integer )

### Returns: bigint

### Language: PLPGSQL

This processes the SET_MOVE_TABLE event. The table is moved to the destination set.

    declare
    	p_tab_id			alias for $1;
    	p_new_set_id		alias for $2;
    	v_old_set_id		int4;
    	v_origin			int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Get the tables current set
    	-- ----
    	select tab_set into v_old_set_id from schemadoc.sl_table
    			where tab_id = p_tab_id;
    	if not found then
    		raise exception 'Slony-I: table %d not found', p_tab_id;
    	end if;

    	-- ----
    	-- Check that both sets exist and originate here
    	-- ----
    	if p_new_set_id = v_old_set_id then
    		raise exception 'Slony-I: set ids cannot be identical';
    	end if;
    	select set_origin into v_origin from schemadoc.sl_set
    			where set_id = p_new_set_id;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_new_set_id;
    	end if;
    	if v_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_new_set_id;
    	end if;

    	select set_origin into v_origin from schemadoc.sl_set
    			where set_id = v_old_set_id;
    	if not found then
    		raise exception 'Slony-I: set % not found', v_old_set_id;
    	end if;
    	if v_origin != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: set % does not originate on local node',
    				v_old_set_id;
    	end if;

    	-- ----
    	-- Check that both sets are subscribed by the same set of nodes
    	-- ----
    	if exists (select true from schemadoc.sl_subscribe SUB1
    				where SUB1.sub_set = p_new_set_id
    				and SUB1.sub_receiver not in (select SUB2.sub_receiver
    						from schemadoc.sl_subscribe SUB2
    						where SUB2.sub_set = v_old_set_id))
    	then
    		raise exception 'Slony-I: subscriber lists of set % and % are different',
    				p_new_set_id, v_old_set_id;
    	end if;

    	if exists (select true from schemadoc.sl_subscribe SUB1
    				where SUB1.sub_set = v_old_set_id
    				and SUB1.sub_receiver not in (select SUB2.sub_receiver
    						from schemadoc.sl_subscribe SUB2
    						where SUB2.sub_set = p_new_set_id))
    	then
    		raise exception 'Slony-I: subscriber lists of set % and % are different',
    				v_old_set_id, p_new_set_id;
    	end if;

    	-- ----
    	-- Change the set the table belongs to
    	-- ----
    	perform schemadoc.createEvent('_schemadoc', 'SYNC', NULL);
    	perform schemadoc.setMoveTable_int(p_tab_id, p_new_set_id);
    	return  schemadoc.createEvent('_schemadoc', 'SET_MOVE_TABLE',
    			p_tab_id, p_new_set_id);
    end;

## Function: setmovetable_int( integer, integer )

### Returns: integer

### Language: PLPGSQL

    declare
    	p_tab_id			alias for $1;
    	p_new_set_id		alias for $2;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Move the table to the new set
    	-- ----
    	update schemadoc.sl_table
    			set tab_set = p_new_set_id
    			where tab_id = p_tab_id;

    	return p_tab_id;
    end;

## Function: setsessionrole( name, text )

### Returns: text

### Language: C

not yet documented

    _Slony_I_setSessionRole

## Function: slonyversion( )

### Returns: text

### Language: PLPGSQL

Returns the version number of the slony schema

    begin
    	return ''	|| schemadoc.slonyVersionMajor() || '.'
    				|| schemadoc.slonyVersionMinor() || '.'
    				|| schemadoc.slonyVersionPatchlevel();
    end;

## Function: slonyversionmajor( )

### Returns: integer

### Language: PLPGSQL

Returns the major version number of the slony schema

    begin
    	return 1;
    end;

## Function: slonyversionminor( )

### Returns: integer

### Language: PLPGSQL

Returns the minor version number of the slony schema

    begin
    	return 1;
    end;

## Function: slonyversionpatchlevel( )

### Returns: integer

### Language: PLPGSQL

Returns the version patch level of the slony schema

    begin
    	return 0;
    end;

## Function: storelisten( integer, integer, integer )

### Returns: bigint

### Language: PLPGSQL

FUNCTION storeListen (li_origin, li_provider, li_receiver) generate STORE_LISTEN event, indicating that receiver node li_receiver listens to node li_provider in order to get messages coming from node li_origin.

    declare
    	p_li_origin		alias for $1;
    	p_li_provider	alias for $2;
    	p_li_receiver	alias for $3;
    begin
    	perform schemadoc.storeListen_int (p_li_origin, p_li_provider, p_li_receiver);
    	return  schemadoc.createEvent ('_schemadoc', 'STORE_LISTEN',
    			p_li_origin, p_li_provider, p_li_receiver);
    end;

## Function: storelisten_int( integer, integer, integer )

### Returns: integer

### Language: PLPGSQL

FUNCTION storeListen_int (li_origin, li_provider, li_receiver) Process STORE_LISTEN event, indicating that receiver node li_receiver listens to node li_provider in order to get messages coming from node li_origin.

    declare
    	p_li_origin		alias for $1;
    	p_li_provider	alias for $2;
    	p_li_receiver	alias for $3;
    	v_exists		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	select 1 into v_exists
    			from schemadoc.sl_listen
    			where li_origin = p_li_origin
    			and li_provider = p_li_provider
    			and li_receiver = p_li_receiver;
    	if not found then
    		-- ----
    		-- In case we receive STORE_LISTEN events before we know
    		-- about the nodes involved in this, we generate those nodes
    		-- as pending.
    		-- ----
    		if not exists (select 1 from schemadoc.sl_node
    						where no_id = p_li_origin) then
    			perform schemadoc.storeNode_int (p_li_origin, '<event pending>');
    		end if;
    		if not exists (select 1 from schemadoc.sl_node
    						where no_id = p_li_provider) then
    			perform schemadoc.storeNode_int (p_li_provider, '<event pending>');
    		end if;
    		if not exists (select 1 from schemadoc.sl_node
    						where no_id = p_li_receiver) then
    			perform schemadoc.storeNode_int (p_li_receiver, '<event pending>');
    		end if;

    		insert into schemadoc.sl_listen
    				(li_origin, li_provider, li_receiver) values
    				(p_li_origin, p_li_provider, p_li_receiver);
    	end if;

    	return 0;
    end;

## Function: storenode( integer, text )

### Returns: bigint

### Language: PLPGSQL

no_id - Node ID # no_comment - Human-oriented comment Generate the STORE_NODE event for node no_id

    declare
    	p_no_id			alias for $1;
    	p_no_comment	alias for $2;
    begin
    	perform schemadoc.storeNode_int (p_no_id, p_no_comment);
    	return  schemadoc.createEvent('_schemadoc', 'STORE_NODE',
    									p_no_id, p_no_comment);
    end;

## Function: storenode_int( integer, text )

### Returns: integer

### Language: PLPGSQL

no_id - Node ID # no_comment - Human-oriented comment Internal function to process the STORE_NODE event for node no_id

    declare
    	p_no_id			alias for $1;
    	p_no_comment	alias for $2;
    	v_old_row		record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check if the node exists
    	-- ----
    	select * into v_old_row
    			from schemadoc.sl_node
    			where no_id = p_no_id
    			for update;
    	if found then
    		-- ----
    		-- Node exists, update the existing row.
    		-- ----
    		update schemadoc.sl_node
    				set no_comment = p_no_comment
    				where no_id = p_no_id;
    	else
    		-- ----
    		-- New node, insert the sl_node row
    		-- ----
    		insert into schemadoc.sl_node
    				(no_id, no_active, no_comment) values
    				(p_no_id, 'f', p_no_comment);
    	end if;

    	return p_no_id;
    end;

## Function: storepath( integer, integer, text, integer )

### Returns: bigint

### Language: PLPGSQL

FUNCTION storePath (pa_server, pa_client, pa_conninfo, pa_connretry) Generate the STORE_PATH event indicating that node pa_client can access node pa_server using DSN pa_conninfo

    declare
    	p_pa_server		alias for $1;
    	p_pa_client		alias for $2;
    	p_pa_conninfo	alias for $3;
    	p_pa_connretry	alias for $4;
    begin
    	perform schemadoc.storePath_int(p_pa_server, p_pa_client,
    			p_pa_conninfo, p_pa_connretry);
    	return  schemadoc.createEvent('_schemadoc', 'STORE_PATH',
    			p_pa_server, p_pa_client, p_pa_conninfo, p_pa_connretry);
    end;

## Function: storepath_int( integer, integer, text, integer )

### Returns: integer

### Language: PLPGSQL

FUNCTION storePath (pa_server, pa_client, pa_conninfo, pa_connretry) Process the STORE_PATH event indicating that node pa_client can access node pa_server using DSN pa_conninfo

    declare
    	p_pa_server		alias for $1;
    	p_pa_client		alias for $2;
    	p_pa_conninfo	alias for $3;
    	p_pa_connretry	alias for $4;
    	v_dummy			int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check if the path already exists
    	-- ----
    	select 1 into v_dummy
    			from schemadoc.sl_path
    			where pa_server = p_pa_server
    			and pa_client = p_pa_client
    			for update;
    	if found then
    		-- ----
    		-- Path exists, update pa_conninfo
    		-- ----
    		update schemadoc.sl_path
    				set pa_conninfo = p_pa_conninfo,
    					pa_connretry = p_pa_connretry
    				where pa_server = p_pa_server
    				and pa_client = p_pa_client;
    	else
    		-- ----
    		-- New path
    		--
    		-- In case we receive STORE_PATH events before we know
    		-- about the nodes involved in this, we generate those nodes
    		-- as pending.
    		-- ----
    		if not exists (select 1 from schemadoc.sl_node
    						where no_id = p_pa_server) then
    			perform schemadoc.storeNode_int (p_pa_server, '<event pending>');
    		end if;
    		if not exists (select 1 from schemadoc.sl_node
    						where no_id = p_pa_client) then
    			perform schemadoc.storeNode_int (p_pa_client, '<event pending>');
    		end if;
    		insert into schemadoc.sl_path
    				(pa_server, pa_client, pa_conninfo, pa_connretry) values
    				(p_pa_server, p_pa_client, p_pa_conninfo, p_pa_connretry);
    	end if;

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	return 0;
    end;

## Function: storeset( integer, text )

### Returns: bigint

### Language: PLPGSQL

Generate STORE_SET event for set set_id with human readable comment set_comment

    declare
    	p_set_id			alias for $1;
    	p_set_comment		alias for $2;
    	v_local_node_id		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');

    	insert into schemadoc.sl_set
    			(set_id, set_origin, set_comment) values
    			(p_set_id, v_local_node_id, p_set_comment);

    	return schemadoc.createEvent('_schemadoc', 'STORE_SET',
    			p_set_id, v_local_node_id, p_set_comment);
    end;

## Function: storeset_int( integer, integer, text )

### Returns: integer

### Language: PLPGSQL

storeSet_int (set_id, set_origin, set_comment) Process the STORE_SET event, indicating the new set with given ID, origin node, and human readable comment.

    declare
    	p_set_id			alias for $1;
    	p_set_origin		alias for $2;
    	p_set_comment		alias for $3;
    	v_dummy				int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	select 1 into v_dummy
    			from schemadoc.sl_set
    			where set_id = p_set_id
    			for update;
    	if found then
    		update schemadoc.sl_set
    				set set_comment = p_set_comment
    				where set_id = p_set_id;
    	else
    		if not exists (select 1 from schemadoc.sl_node
    						where no_id = p_set_origin) then
    			perform schemadoc.storeNode_int (p_set_origin, '<event pending>');
    		end if;
    		insert into schemadoc.sl_set
    				(set_id, set_origin, set_comment) values
    				(p_set_id, p_set_origin, p_set_comment);
    	end if;

    	return p_set_id;
    end;

## Function: storetrigger( integer, name )

### Returns: bigint

### Language: PLPGSQL

storeTrigger (trig_tabid, trig_tgname) Submits STORE_TRIGGER event to indicate that trigger trig_tgname on replicated table trig_tabid will NOT be disabled.

    declare
    	p_trig_tabid		alias for $1;
    	p_trig_tgname		alias for $2;
    begin
    	perform schemadoc.storeTrigger_int(p_trig_tabid, p_trig_tgname);
    	return  schemadoc.createEvent('_schemadoc', 'STORE_TRIGGER',
    			p_trig_tabid, p_trig_tgname);
    end;

## Function: storetrigger_int( integer, name )

### Returns: integer

### Language: PLPGSQL

storeTrigger_int (trig_tabid, trig_tgname) Processes STORE_TRIGGER event to make sure that trigger trig_tgname on replicated table trig_tabid is NOT disabled.

    declare
    	p_trig_tabid		alias for $1;
    	p_trig_tgname		alias for $2;
    	v_tab_altered		boolean;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Get the current table status (altered or not)
    	-- ----
    	select tab_altered into v_tab_altered
    			from schemadoc.sl_table where tab_id = p_trig_tabid;
    	if not found then
    		-- ----
    		-- Not found is no hard error here, because that might
    		-- mean that we are not subscribed to that set
    		-- ----
    		return 0;
    	end if;

    	-- ----
    	-- If the table is modified for replication, restore the original state
    	-- ----
    	if v_tab_altered then
    		perform schemadoc.alterTableRestore(p_trig_tabid);
    	end if;

    	-- ----
    	-- Make sure that an entry for this trigger exists
    	-- ----
    	delete from schemadoc.sl_trigger
    			where trig_tabid = p_trig_tabid
    			  and trig_tgname = p_trig_tgname;
    	insert into schemadoc.sl_trigger (
    				trig_tabid, trig_tgname
    			) values (
    				p_trig_tabid, p_trig_tgname
    			);

    	-- ----
    	-- Put the table back into replicated state if it was
    	-- ----
    	if v_tab_altered then
    		perform schemadoc.alterTableForReplication(p_trig_tabid);
    	end if;

    	return p_trig_tabid;
    end;

## Function: subscribeset( integer, integer, integer, boolean )

### Returns: bigint

### Language: PLPGSQL

subscribeSet (sub_set, sub_provider, sub_receiver, sub_forward) Makes sure that the receiver is not the provider, then stores the subscription, and publishes the SUBSCRIBE_SET event to other nodes.

    declare
    	p_sub_set			alias for $1;
    	p_sub_provider		alias for $2;
    	p_sub_receiver		alias for $3;
    	p_sub_forward		alias for $4;
    	v_set_origin		int4;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that this is called on the receiver node
    	-- ----
    	if p_sub_receiver != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: subscribeSet() must be called on receiver';
    	end if;

    	-- ----
    	-- Check that the origin and provider of the set are remote
    	-- ----
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_sub_set;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_sub_set;
    	end if;
    	if v_set_origin = p_sub_receiver then
    		raise exception
    				'Slony-I: set origin and receiver cannot be identical';
    	end if;
    	if p_sub_receiver = p_sub_provider then
    		raise exception
    				'Slony-I: set provider and receiver cannot be identical';
    	end if;

    	-- ----
    	-- Call the internal procedure to store the subscription
    	-- ----
    	perform schemadoc.subscribeSet_int(p_sub_set, p_sub_provider,
    			p_sub_receiver, p_sub_forward);

    	-- ----
    	-- Submit listen management events
    	-- ----
    	perform schemadoc.GenerateListensOnSubscribe(p_sub_provider, p_sub_receiver);

    	-- ----
    	-- Create the SUBSCRIBE_SET event
    	-- ----
    	return  schemadoc.createEvent('_schemadoc', 'SUBSCRIBE_SET',
    			p_sub_set, p_sub_provider, p_sub_receiver,
    			case p_sub_forward when true then 't' else 'f' end);
    end;

## Function: subscribeset_int( integer, integer, integer, boolean )

### Returns: integer

### Language: PLPGSQL

subscribeSet_int (sub_set, sub_provider, sub_receiver, sub_forward) Internal actions for subscribing receiver sub_receiver to subscription set sub_set.

    declare
    	p_sub_set			alias for $1;
    	p_sub_provider		alias for $2;
    	p_sub_receiver		alias for $3;
    	p_sub_forward		alias for $4;
    	v_set_origin		int4;
    	v_sub_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Provider change is only allowed for active sets
    	-- ----
    	if p_sub_receiver = schemadoc.getLocalNodeId('_schemadoc') then
    		select sub_active into v_sub_row from schemadoc.sl_subscribe
    				where sub_set = p_sub_set
    				and sub_receiver = p_sub_receiver;
    		if found then
    			if not v_sub_row.sub_active then
    				raise exception 'Slony-I: set % is not active, cannot change provider',
    						p_sub_set;
    			end if;
    		end if;
    	end if;

    	-- ----
    	-- Try to change provider and/or forward for an existing subscription
    	-- ----
    	update schemadoc.sl_subscribe
    			set sub_provider = p_sub_provider,
    				sub_forward = p_sub_forward
    			where sub_set = p_sub_set
    			and sub_receiver = p_sub_receiver;
    	if found then
    		return p_sub_set;
    	end if;

    	-- ----
    	-- Not found, insert a new one
    	-- ----
    	if not exists (select true from schemadoc.sl_path
    			where pa_server = p_sub_provider
    			and pa_client = p_sub_receiver)
    	then
    		insert into schemadoc.sl_path
    				(pa_server, pa_client, pa_conninfo, pa_connretry)
    				values
    				(p_sub_provider, p_sub_receiver,
    				'<event pending>', 10);
    	end if;
    	insert into schemadoc.sl_subscribe
    			(sub_set, sub_provider, sub_receiver, sub_forward, sub_active)
    			values (p_sub_set, p_sub_provider, p_sub_receiver,
    				p_sub_forward, false);

    	-- ----
    	-- If the set origin is here, then enable the subscription
    	-- ----
    	select set_origin into v_set_origin
    			from schemadoc.sl_set
    			where set_id = p_sub_set;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_sub_set;
    	end if;

    	if v_set_origin = schemadoc.getLocalNodeId('_schemadoc') then
    		perform schemadoc.createEvent('_schemadoc', 'ENABLE_SUBSCRIPTION',
    				p_sub_set, p_sub_provider, p_sub_receiver,
    				case p_sub_forward when true then 't' else 'f' end);
    		perform schemadoc.enableSubscription(p_sub_set,
    				p_sub_provider, p_sub_receiver);
    	end if;

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	return p_sub_set;
    end;

## Function: tableaddkey( text )

### Returns: text

### Language: PLPGSQL

tableAddKey (tab_fqname) - if the table has not got a column of the form _Slony-I_<clustername>_rowID, then add it as a bigint, defaulted to nextval() for a sequence created for the cluster.

    declare
    	p_tab_fqname	alias for $1;
    	v_attkind		text default '';
    	v_attrow		record;
    	v_have_serial	bool default 'f';
    begin
    	--
    	-- Loop over the attributes of this relation
    	-- and add a "v" for every user column, and a "k"
    	-- if we find the Slony-I special serial column.
    	--
    	for v_attrow in select PGA.attnum, PGA.attname
    			from "pg_catalog".pg_class PGC,
    			    "pg_catalog".pg_namespace PGN,
    				"pg_catalog".pg_attribute PGA
    			where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			    "pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    				and PGN.oid = PGC.relnamespace
    				and PGA.attrelid = PGC.oid
    				and not PGA.attisdropped
    				and PGA.attnum > 0
    			order by attnum
    	loop
    		if v_attrow.attname = '_Slony-I_schemadoc_rowID' then
    		    v_attkind := v_attkind || 'k';
    			v_have_serial := 't';
    		else
    			v_attkind := v_attkind || 'v';
    		end if;
    	end loop;

    	--
    	-- A table must have at least one attribute, so not finding
    	-- anything means the table does not exist.
    	--
    	if not found then
    		raise exception 'Slony-I: table % not found', p_tab_fqname;
    	end if;

    	--
    	-- If it does not have the special serial column, we
    	-- have to add it. This will be only half way done.
    	-- The function to add the table to the set must finish
    	-- these definitions with NOT NULL and UNIQUE after
    	-- updating all existing rows.
    	--
    	if not v_have_serial then
    		execute 'lock table ' || p_tab_fqname ||
    			' in access exclusive mode';
    		execute 'alter table only ' || p_tab_fqname ||
    			' add column "_Slony-I_schemadoc_rowID" bigint;';
    		execute 'alter table only ' || p_tab_fqname ||
    			' alter column "_Slony-I_schemadoc_rowID" ' ||
    			' set default "pg_catalog".nextval(''schemadoc.sl_rowid_seq'');';

    		v_attkind := v_attkind || 'k';
    	end if;

    	--
    	-- Return the resulting Slony-I attkind
    	--
    	return v_attkind;
    end;

## Function: tabledropkey( integer )

### Returns: integer

### Language: PLPGSQL

tableDropKey (tab_id) If the specified table has a column "_Slony-I_<clustername>_rowID", then drop it.

    declare
    	p_tab_id		alias for $1;
    	v_tab_fqname	text;
    	v_tab_oid		oid;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Construct the tables fully qualified name and get its oid
    	-- ----
    	select "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    				"pg_catalog".quote_ident(PGC.relname),
    				PGC.oid into v_tab_fqname, v_tab_oid
    			from schemadoc.sl_table T,
    				"pg_catalog".pg_class PGC,
    				"pg_catalog".pg_namespace PGN
    			where T.tab_id = p_tab_id
    				and T.tab_reloid = PGC.oid
    				and PGC.relnamespace = PGN.oid;
    	if not found then
    		raise exception 'Slony-I: table with ID % not found', p_tab_id;
    	end if;

    	-- ----
    	-- Drop the special serial ID column if the table has it
    	-- ----
    	if exists (select true from "pg_catalog".pg_attribute
    			where attrelid = v_tab_oid
    				and attname = '_Slony-I_schemadoc_rowID')
    	then
    		execute 'lock table ' || v_tab_fqname ||
    				' in access exclusive mode';
    		execute 'alter table ' || v_tab_fqname ||
    				' drop column "_Slony-I_schemadoc_rowID"';
    	end if;

    	return p_tab_id;
    end;

## Function: tablehasserialkey( text )

### Returns: boolean

### Language: PLPGSQL

tableHasSerialKey (tab_fqname) Checks if a table has our special serial key column that is used if the table has no natural unique constraint.

    declare
    	p_tab_fqname	alias for $1;
    	v_attnum		int2;
    begin
    	select PGA.attnum into v_attnum
    			from "pg_catalog".pg_class PGC,
    				"pg_catalog".pg_namespace PGN,
    				"pg_catalog".pg_attribute PGA
    			where "pg_catalog".quote_ident(PGN.nspname) || '.' ||
    				"pg_catalog".quote_ident(PGC.relname) = p_tab_fqname
    				and PGC.relnamespace = PGN.oid
    				and PGA.attrelid = PGC.oid
    				and PGA.attname = '_Slony-I_schemadoc_rowID'
    				and not PGA.attisdropped;
    	return found;
    end;

## Function: terminatenodeconnections( name )

### Returns: integer

### Language: C

terminates connections to the node and terminates the process

    _Slony_I_terminateNodeConnections

## Function: uninstallnode( )

### Returns: integer

### Language: PLPGSQL

Reset the whole database to standalone by removing the whole replication system.

    declare
    	v_tab_row		record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- This is us ... time for suicide! Restore all tables to
    	-- their original status.
    	-- ----
    	for v_tab_row in select * from schemadoc.sl_table loop
    		perform schemadoc.alterTableRestore(v_tab_row.tab_id);
    		perform schemadoc.tableDropKey(v_tab_row.tab_id);
    	end loop;

    	raise notice 'Slony-I: Please drop schema "_schemadoc"';
    	return 0;
    end;

## Function: unlockset( integer )

### Returns: integer

### Language: PLPGSQL

Remove the special trigger from all tables of a set that disables access to it.

    declare
    	p_set_id			alias for $1;
    	v_local_node_id		int4;
    	v_set_row			record;
    	v_tab_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that the set exists and that we are the origin
    	-- and that it is not already locked.
    	-- ----
    	v_local_node_id := schemadoc.getLocalNodeId('_schemadoc');
    	select * into v_set_row from schemadoc.sl_set
    			where set_id = p_set_id
    			for update;
    	if not found then
    		raise exception 'Slony-I: set % not found', p_set_id;
    	end if;
    	if v_set_row.set_origin <> v_local_node_id then
    		raise exception 'Slony-I: set % does not originate on local node',
    				p_set_id;
    	end if;
    	if v_set_row.set_locked isnull then
    		raise exception 'Slony-I: set % is not locked', p_set_id;
    	end if;

    	-- ----
    	-- Drop the lockedSet trigger from all tables in the set.
    	-- ----
    	for v_tab_row in select T.tab_id,
    			"pg_catalog".quote_ident(PGN.nspname) || '.' ||
    			"pg_catalog".quote_ident(PGC.relname) as tab_fqname
    			from schemadoc.sl_table T,
    				"pg_catalog".pg_class PGC, "pg_catalog".pg_namespace PGN
    			where T.tab_set = p_set_id
    				and T.tab_reloid = PGC.oid
    				and PGC.relnamespace = PGN.oid
    			order by tab_id
    	loop
    		execute 'drop trigger "_schemadoc_lockedset_' ||
    				v_tab_row.tab_id || '" on ' || v_tab_row.tab_fqname;
    	end loop;

    	-- ----
    	-- Clear out the set_locked field
    	-- ----
    	update schemadoc.sl_set
    			set set_locked = NULL
    			where set_id = p_set_id;

    	return p_set_id;
    end;

## Function: unsubscribeset( integer, integer )

### Returns: bigint

### Language: PLPGSQL

unsubscribeSet (sub_set, sub_receiver) Unsubscribe node sub_receiver from subscription set sub_set. This is invoked on the receiver node. It verifies that this does not break any chains (e.g. - where sub_receiver is a provider for another node), then restores tables, drops Slony-specific keys, drops table entries for the set, drops the subscription, and generates an UNSUBSCRIBE_SET node to publish that the node is being dropped.

    declare
    	p_sub_set			alias for $1;
    	p_sub_receiver		alias for $2;
    	v_tab_row			record;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- Check that this is called on the receiver node
    	-- ----
    	if p_sub_receiver != schemadoc.getLocalNodeId('_schemadoc') then
    		raise exception 'Slony-I: unsubscribeSet() must be called on receiver';
    	end if;

    	-- ----
    	-- Check that this does not break any chains
    	-- ----
    	if exists (select true from schemadoc.sl_subscribe
    			where sub_set = p_sub_set
    				and sub_provider = p_sub_receiver)
    	then
    		raise exception 'Slony-I: Cannot unsubscibe set % while being provider',
    				p_sub_set;
    	end if;

    	-- ----
    	-- Restore all tables original triggers and rules and remove
    	-- our replication stuff.
    	-- ----
    	for v_tab_row in select tab_id from schemadoc.sl_table
    			where tab_set = p_sub_set
    			order by tab_id
    	loop
    		perform schemadoc.alterTableRestore(v_tab_row.tab_id);
    		perform schemadoc.tableDropKey(v_tab_row.tab_id);
    	end loop;

    	-- ----
    	-- Remove the setsync status. This will also cause the
    	-- worker thread to ignore the set and stop replicating
    	-- right now.
    	-- ----
    	delete from schemadoc.sl_setsync
    			where ssy_setid = p_sub_set;

    	-- ----
    	-- Remove all sl_table and sl_sequence entries for this set.
    	-- Should we ever subscribe again, the initial data
    	-- copy process will create new ones.
    	-- ----
    	delete from schemadoc.sl_table
    			where tab_set = p_sub_set;
    	delete from schemadoc.sl_sequence
    			where seq_set = p_sub_set;

    	-- ----
    	-- Call the internal procedure to drop the subscription
    	-- ----
    	perform schemadoc.unsubscribeSet_int(p_sub_set, p_sub_receiver);

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	-- ----
    	-- Create the UNSUBSCRIBE_SET event
    	-- ----
    	return  schemadoc.createEvent('_schemadoc', 'UNSUBSCRIBE_SET',
    			p_sub_set, p_sub_receiver);
    end;

## Function: unsubscribeset_int( integer, integer )

### Returns: integer

### Language: PLPGSQL

unsubscribeSet_int (sub_set, sub_receiver) All the REAL work of removing the subscriber is done before the event is generated, so this function just has to drop the references to the subscription in sl_subscribe.

    declare
    	p_sub_set			alias for $1;
    	p_sub_receiver		alias for $2;
    begin
    	-- ----
    	-- Grab the central configuration lock
    	-- ----
    	lock table schemadoc.sl_config_lock;

    	-- ----
    	-- All the real work is done before event generation on the
    	-- subscriber.
    	-- ----
    	delete from schemadoc.sl_subscribe
    			where sub_set = p_sub_set
    				and sub_receiver = p_sub_receiver;

    	-- Rewrite sl_listen table
    	perform schemadoc.RebuildListenEntries();

    	return p_sub_set;
    end;

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