From: | "Guillaume Smet" <guillaume(dot)smet(at)gmail(dot)com> |
---|---|
To: | "pgsql-hackers list" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Suboptimal plan choice problem with 8.3RC2 |
Date: | 2008-01-22 18:52:04 |
Message-ID: | 1d4e0c10801221052j3b530ae8n33f7bfc359b1cfd5@mail.gmail.com |
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Lists: | pgsql-hackers |
Hi -hackers,
While testing RC2 on the new servers of one of our customers, I found
a query really slow on the new server which is quite fast on the old
box currently in production (production is 8.1 at the moment).
If I set enable_nestloop to off, the query is fast (the plan is
different from the 8.1 plan though).
I attached:
- the plan with regular configuration;
- the plan after disabling nested loops;
- the plan obtained with 8.1 on the current production box;
- the relevant configuration and schema of the concerned tables.
The plans are really too different to find a narrower test case so
it's the real test case.
Feel free to ask any additional information or tests.
Regards,
--
Guillaume
Attachment | Content-Type | Size |
---|---|---|
configuration-and-schema.txt | text/plain | 9.1 KB |
nested-loop-plan.txt | text/plain | 3.0 KB |
nested-loop-disabled-plan.txt | text/plain | 4.1 KB |
8.1-plan.txt | text/plain | 3.4 KB |
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