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Re: Using system tables directly takes many hours, using temp tables with no indexes takes a few seconds for geometry_columns view. - Mailing list pgsql-performance

From Justin Pryzby
Subject Re: Using system tables directly takes many hours, using temp tables with no indexes takes a few seconds for geometry_columns view.
Date
Msg-id 20220323131921.GR28503@telsasoft.com
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In response to Using system tables directly takes many hours, using temp tables with no indexes takes a few seconds for geometry_columns view.  (Lars Aksel Opsahl <Lars.Opsahl@nibio.no>)
Responses Re: Using system tables directly takes many hours, using temp tables with no indexes takes a few seconds for geometry_columns view.  (Lars Aksel Opsahl <Lars.Opsahl@nibio.no>)
Re: Using system tables directly takes many hours, using temp tables with no indexes takes a few seconds for geometry_columns view.  (Lars Aksel Opsahl <Lars.Opsahl@nibio.no>)
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On Wed, Mar 23, 2022 at 09:44:09AM +0000, Lars Aksel Opsahl wrote:
> Why is temp tables with no indexes much faster system tables with indexes ?

I think the "temp table" way is accidentally faster due to having no
statistics, not because it has no indexes.  If you run ANALYZE, you may hit the
same issue (or, maybe you just need to VACUUM ANALYZE your system catalogs).

-- 
Justin

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