Hi, That's my solution candidate: CREATE OR REPLACE FUNCTION isnotempty() RETURNS boolean AS ' SELECT (count(*) = 1) FROM (SELECT osm_id FROM planet_osm_point LIMIT 1 OFFSET 100000) tmp ' LANGUAGE SQL; Yours, Stefan 2011/5/28 Stefan Keller <sfkeller@xxxxxxxxx>: > Hi, > > Iâd like to monitor a table in a read-only Postgres database by > writing a PL/pgSQL function. > The database gets periodically overwritten by a mirroring loading process. > The success criteria is, that the table contains at least some records > (actually at least more than 100000). > > The first idea which comes to oneâs mind is probably a count(*): > > SELECT CASE WHEN (count(*) > 10000) THEN 'yes' ELSE 'no' END > FROM planet_osm_point; > > But my goal is to consume as few Postgres server resources as possible. > So my idea is to retrieve an arbitrary record, like this: > > SELECT CASE WHEN (osm_id::text > '') THEN 'yes' ELSE 'no' END > FROM planet_osm_point LIMIT 1 OFFSET 1000000; > > Is there anyone having an even better Âbetter idea? > > Yours, Stefan > -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
