Mark Rostron <mrostron@xxxxxxx> writes: > This message is a request for information about the "initplan" operation in explain plan. An initplan is a sub-SELECT that only needs to be executed once because it has no dependency on the immediately surrounding query level. The cases you show here are from sub-SELECTs like this: (select min(wu_id) from work_active limit 1) which yields a value that's independent of anything in the outer query. If there were an outer reference in there, you'd get a SubPlan instead, because the subquery would need to be done over again for each row of the outer query. BTW, adding LIMIT 1 to an aggregate query is pretty pointless. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
