Let's say you have one partitioned table, "tbl_p", partitioned according to the PK "p_pk". I have made something similar with triggers, basing myself on the manual for making partitioned tables. According to the manual, optimizer searches the CHECKs of the partitions to determine which table(s) to use (if applicable).
So if one has CHECKs of kind "p_pk = some number", queries like "SELECT * from tbl_p where p_pk = 1" will only be searched in the appropriate table. One can check this with EXPLAIN. So far so good. Now, if one takes a subquery for "1", the optimizer evaluates it first (let's say to "1"), but then searches for it (sequentially) in every partition, which, for large partitions, can be very time-consuming and goes beyond the point of partitioning. Is this normal, or am I missing something? Kind regards, Davor -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
