If you are working with Postgres version >= 8.4, you should look at the WITH RECURSIVE (called recursive CTEs) feature:
http://www.postgresql.org/docs/8.4/static/queries-with.html Regards, On Thu, Mar 31, 2011 at 12:19 PM, salah jubeh <s_ju...@yahoo.com> wrote: > > > Hello, > > I have written this function which is simply returns the entities which > depends on a certain entity. It works fine if the dependency tree is not > long. However, If I have an entity which are linked to many other entities I > get > > stack depth limit exceeded > HINT: Increase the configuration parameter "max_stack_depth", after > ensuring the platform's stack depth limit is adequate. > > I wrote this function to know exactly what are the tables, views that will > be doped if I use cascade option. I want to get around this issue without > changing the server configuration > > > CREATE OR REPLACE FUNCTION dependon(var text) > RETURNS SETOF text AS > $BODY$ > DECLARE > node record; > child_node record; > BEGIN > > FOR node IN -- For inheritance > SELECT objid::regclass::text as relname > FROM pg_catalog.pg_depend > WHERE refobjid = $1::regclass::oid AND deptype ='n' AND classid > ='pg_class'::regclass > UNION > -- For rewrite rules > SELECT ev_class::regclass::text as relname > FROM pg_rewrite WHERE oid IN ( SELECT objid FROM > pg_catalog.pg_depend > WHERE refobjid = $1::regclass::oid AND deptype ='n') > UNION > -- For constraints (Forign keys) > SELECT conrelid::regclass::text as relname > FROM pg_constraint WHERE oid in (SELECT objid FROM > pg_catalog.pg_depend > WHERE refobjid = $1::regclass::oid AND deptype ='n') > > LOOP > > RETURN NEXT node.relname; > FOR child_node IN SELECT * FROM dependon(node.relname) > LOOP > RETURN NEXT child_node.dependon; > END LOOP; > > END LOOP; > END > $BODY$ > LANGUAGE 'plpgsql' > > Regards > > -- Gurjeet Singh EnterpriseDB Corporation The Enterprise PostgreSQL Company
