Hi,
During query tuning, users may want to check if GEQO is used or not
to generate a plan. However, users can not know it by simply counting
the number of tables that appear in SQL. I know we can know it by
enabling GEQO_DEBUG flag, but it needs recompiling, so I think it is
inconvenient.
So, I would like to propose to add a debug level message that shows
when PostgreSQL use GEQO. That enables users to easily see it by
just changing log_min_messages.
Use cases are as follows:
- When investigating about the result of planning, user can determine
whether the plan is chosen by the standard planning or GEQO.
- When tuning PostgreSQL, user can determine the suitable value of
geqo_threshold parameter.
Best regards.
--
KAWAMOTO Masaya <kawamoto@sraoss.co.jp>
SRA OSS, Inc. Japan