fx TATEISHI KOJI wrote: > Issuing exactly the same query as PostgreSQL 8.2.21 and PostgreSQL 9.3.2 will > slow the > response by 6.4 ms on average. > What could be the cause? > Measurement method is as follows. > ・ PostgreSQL 8.2.21 installation > ★Measurement > ・ Export DUMP of PostgreSQL 8.2.21 > ・ PostgreSQL 8.2.21 uninstallation > ・ PostgreSQL 9.3.2 installation > ・ Dump import > ★Measurement
It is impossible to answer this with certainty without EXPLAIN (ANALYZE, BUFFERS) output, but my first guess is that the statistics on the 9.3 installation are not up to date. ANALYZE all involved tables, then try again and see if the performance degradation has vanished. If not, start studying the execution plans. Are the parameters in postgresql.conf set the same? Yours, Laurenz Albe -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
