Re: Index Scans become Seq Scans after VACUUM ANALYSE - Mailing list pgsql-hackers

From Thomas Lockhart
Subject Re: Index Scans become Seq Scans after VACUUM ANALYSE
Date
Msg-id 3CBEE364.CB82408A@fourpalms.org
Whole thread Raw
In response to Re: Index Scans become Seq Scans after VACUUM ANALYSE  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
...
> My one most important experience (I've had more than one) with this whole topic
> is DMN's music database, when PostgreSQL uses the index, the query executes in
> a fraction of a second. When "enable_seqscan=true" PostgreSQL refuses to use
> the index, and the query takes a about a minute. No matter how much I analyze,
> I have to disable sequential scan for the system to work correctly.

How about contributing the data and a query? We've all got things that
we would like to change or adjust in the PostgreSQL feature set. If you
can't contribute code, how about organizing some choice datasets for
testing purposes? If the accumulated set is too big for postgresql.org
(probably not, but...) I can host them on my machine.

Most folks seem to not have to manipulate the optimizer to get good
results nowadays. So to make more progress we need to have test cases...
                      - Thomas


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