Of course, the geqo_threshold can be changed so that the geqo be performed in queries that have less than 12 tables. However, we aim to test the GEQO algorithm in conditions where the standard algorithm (dynamic programming) has a high cost to calculate the query plan.
--
Tarcizio Bini
2008/5/28 Tom Lane <tgl@xxxxxxxxxxxxx>:
tarcizioab@xxxxxxxxxxxx writes:See
> I'm using the TPC-H Benchmark for testing of performance in PostgreSQL.
> But it is composed of only 8 tables, which is not enough to call the GEQO
> algorithm.
http://www.postgresql.org/docs/8.3/static/runtime-config-query.html#RUNTIME-CONFIG-QUERY-GEQO
particularly geqo_threshold.
regards, tom lane
