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Re: PostgreSQL does not choose my indexes well - Mailing list pgsql-performance

From	David G. Johnston
Subject	Re: PostgreSQL does not choose my indexes well
Date	April 23, 2020 23:36:15
Msg-id	CAKFQuwbNs3Avhz0vXU3uabymEoxWsXH9bhCiMWDSkhuPt5-mHg@mail.gmail.com Whole thread Raw
In response to	Re: PostgreSQL does not choose my indexes well (Tom Lane <tgl@sss.pgh.pa.us>)
Responses	Re: PostgreSQL does not choose my indexes well
List	pgsql-performance

On Thu, Apr 23, 2020 at 1:33 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:

I find the apparently
unnecessary cast in the partial-index predicate to be suspicious ---
maybe that's blocking matching to the WHERE clause?

I noticed that too...I suspect its related to the ANALYZE result:

Index Scan using idx_tabla_entidad on entidad (cost=0.56..51121.41

rows=1405216 width=20) (actual time=0.037..242.609 rows=1409985 loops=1)
Index Cond: ((cod_tabla)::bigint = 4)

Since the index condition ended up cast to bigint the OP probably wrote the predicate to match.

David J.

From: Tom Lane
Date: 23 April 2020, 23:33:07
Subject: Re: PostgreSQL does not choose my indexes well

From: Tom Lane
Date: 23 April 2020, 23:45:42
Subject: Re: PostgreSQL does not choose my indexes well