On Thu, 2009-11-26 at 05:01 +0100, Pavel Stehule wrote: > It working like: > > 1. EXECUTE SELECT 0 FROM generate_series(1,...); > 2. STORE RESULT TO TABLE zero; > 3. EXECUTE SELECT 1/i FROM zero; > 4. STORE RESULT TO TABLE tmp; > > Problem is in seq execution. Result is stored to destination after > execution - so any materialisation is necessary, >
My example showed that steps 3 and 4 are not executed sequentially, but are executed together. If 3 was executed entirely before 4, then the statement: insert into tmp select 1/i from zero; would have to read the whole table "zero" before an error is encountered. However, the statement errors immediately, showing that steps 3 and 4 are pipelined. Regards, Jeff Davis -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers