Re: [PROPOSAL] Detecting plan changes with plan_id in pg_stat_activity

> Good point. I will separate this patch.

I separated the pg_stat_statements patch. The patch
Introduces a secondary hash that tracks locations of
A query ( by queryid ) in the external file. The hash
remains in lockstep with the pgss_hash using a
synchronization routine. For the default
pg_stat_statements.max = 5000, this hash requires 2MB megabytes
of additional shared memory.

My testing does not show any regression for workloads
In which statements are not issues by multiple users/databases.

However, it shows good improvement, 10-15%, when there
are similar statements that are issues by multiple
users/databases/tracking levels.

Besides this improvement, this will open up the opportunity
to also track plan_id's as discussed earlier in the thread.

Thanks for the feedback.

Regards,

Sami Imseih
Amazon Web Services