Re: BUG: pg_stat_statements query normalization issues with combined queries
Fabien COELHO <coelho@cri.ensmp.fr>
From: Fabien COELHO <coelho@cri.ensmp.fr>
To: PostgreSQL Developers <pgsql-hackers@postgresql.org>
Date: 2016-12-20T09:55:08Z
Lists: pgsql-hackers
>> I was expecting the 2 combined queries either to be separated in individual
>> queries "SELECT data FROM Stuff WHERE id = ?" or in one large queries with
>> three ?, but not the above result...
>
> Oops, I forgot the attachement, see repeat script on 9.6.1
After some quick investigation, I concluded that the issue is that the
whole combined query string is used instead of the part refering to the
actual query being processed.
As a result:
- the full un-normalized string is used for both BEGIN & COMMIT
=> n shared entries, one for each actual query, begin & commit are mixed together
- the fist-part only normalized string is used for each SELECT
=> 1 shared entry with "query" is the first partially
normalied encountered combined query
--
Fabien.
Commits
-
Teach contrib/pg_stat_statements to handle multi-statement commands better.
- 83f2061dd037 10.0 landed
-
Change representation of statement lists, and add statement location info.
- ab1f0c822571 10.0 landed
-
Revert my bad decision of about a year ago to make PortalDefineQuery
- 1591fcbec77f 8.4.0 cited