add_empty_table_to_replication(integer, integer, text, text, text, text)

Slony-I 2.0.4 Documentation
Prev | Fast Backward | Chapter 1. Schema schemadoc | Fast Forward | Next

# 1.19. add_empty_table_to_replication(integer, integer, text, text, text, text)

Function Properties

Language: PLPGSQL

Return Type: bigint

Verify that a table is empty, and add it to replication. tab_idxname is optional - if NULL, then we use the primary key.

    declare
      p_set_id alias for $1;
      p_tab_id alias for $2;
      p_nspname alias for $3;
      p_tabname alias for $4;
      p_idxname alias for $5;
      p_comment alias for $6;

      prec record;
      v_origin int4;
      v_isorigin boolean;
      v_fqname text;
      v_query text;
      v_rows integer;
      v_idxname text;

    begin
    -- Need to validate that the set exists; the set will tell us if this is the origin
      select set_origin into v_origin from sl_set where set_id = p_set_id;
      if not found then
    	raise exception 'add_empty_table_to_replication: set % not found!', p_set_id;
      end if;

    -- Need to be aware of whether or not this node is origin for the set
       v_isorigin := ( v_origin = getLocalNodeId('_schemadoc') );

       v_fqname := '"' || p_nspname || '"."' || p_tabname || '"';
    -- Take out a lock on the table
       v_query := 'lock ' || v_fqname || ';';
       execute v_query;

       if v_isorigin then
    	-- On the origin, verify that the table is empty, failing if it has any tuples
            v_query := 'select 1 as tuple from ' || v_fqname || ' limit 1;';
    	execute v_query into prec;
            GET DIAGNOSTICS v_rows = ROW_COUNT;
    	if v_rows = 0 then
    		raise notice 'add_empty_table_to_replication: table % empty on origin - OK', v_fqname;
    	else
    		raise exception 'add_empty_table_to_replication: table % contained tuples on origin node %', v_fqname, v_origin;
    	end if;
       else
    	-- On other nodes, TRUNCATE the table
            v_query := 'truncate ' || v_fqname || ';';
    	execute v_query;
       end if;
    -- If p_idxname is NULL, then look up the PK index, and RAISE EXCEPTION if one does not exist
       if p_idxname is NULL then
    	select c2.relname into prec from pg_catalog.pg_index i, pg_catalog.pg_class c1, pg_catalog.pg_class c2, pg_catalog.pg_namespace n where i.indrelid = c1.oid and i.indexrelid = c2.oid and c1.relname = p_tabname and i.indisprimary and n.nspname = p_nspname and n.oid = c1.relnamespace;
    	if not found then
    		raise exception 'add_empty_table_to_replication: table % has no primary key and no candidate specified!', v_fqname;
    	else
    		v_idxname := prec.relname;
    	end if;
       else
    	v_idxname := p_idxname;
       end if;
       return setAddTable_int(p_set_id, p_tab_id, v_fqname, v_idxname, p_comment);
    end

Prev | Home | Next
Table: `sl_table` | Up | add_missing_table_field(text, text, text, text)