Re: Inheritance, unique keys and performance - Mailing list pgsql-performance

From Tom Lane
Subject Re: Inheritance, unique keys and performance
Date
Msg-id 7212.1200250003@sss.pgh.pa.us
Whole thread Raw
In response to Re: Inheritance, unique keys and performance  ("Julian Scarfe" <julian@avbrief.com>)
List pgsql-performance
"Julian Scarfe" <julian@avbrief.com> writes:
>> Without the EXPLAIN ANALYZE output, nobody can say whether you have
>> interpreted your performance problem correctly or not.

> Fair enough, Tom.

Okay, so the "expensive function" isn't as expensive as all that ---
it seems to be adding only a few msec to the total runtime.  The
problem you've got is that you need a nestloop-with-inner-indexscan
plan type, where the inner side is an Append group (that is, an
inheritance tree) --- and 8.1 doesn't know how to create such a plan.
If you can update to 8.2 or later it should get better.

            regards, tom lane

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