Re: Index no longer being used, destroying and recreating it restores use. - Mailing list pgsql-general

From Tom Lane
Subject Re: Index no longer being used, destroying and recreating it restores use.
Date
Msg-id 1251078.1591289012@sss.pgh.pa.us
Whole thread Raw
In response to Index no longer being used, destroying and recreating it restores use.  (Koen De Groote <kdg.dev@gmail.com>)
Responses Re: Index no longer being used, destroying and recreating it restoresuse.  (Adrian Klaver <adrian.klaver@aklaver.com>)
List pgsql-general
Koen De Groote <kdg.dev@gmail.com> writes:
> I've got a table with about 30 million rows and a particular index that up
> until recently was actively being used.
> And then it stopped being used and the query that the index was made for,
> is now doing sequential scans.
> Deleting the index and creating it again, seems to fix the problem. The new
> index, which is identical in composition, is being used and the query in
> question no longer uses sequential scans.

It's possible that the index had bloated to the point where the planner
thought it was cheaper to use a seqscan.  Did you make a note of the
cost estimates for the different plans?

            regards, tom lane



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