From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavel Stehule <pavel.stehule@gmail.com>
cc: Ram Pratap Maurya <ram.maurya@lavainternational.in>,
        PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: BUG #17059: postgresql 13 version problem related to query.
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Comments: In-reply-to Pavel Stehule <pavel.stehule@gmail.com>
	message dated "Tue, 15 Jun 2021 21:42:05 +0200"
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Date: Tue, 15 Jun 2021 15:54:35 -0400
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Pavel Stehule <pavel.stehule@gmail.com> writes:
> út 15. 6. 2021 v 21:36 odesílatel Ram Pratap Maurya <
> ram.maurya@lavainternational.in> napsal:
>> Postgresql-12 :
>> ->  Index Scan using retailer_code_12390127_idx
>> on tretailer_mst retailerlist  (cost=0.42..5468.67 rows=146923 width=25)
>> (actual time=0.018..180.502 rows=144211 loops=1)
>>
>> Postgresql-13
>> ->  Index Scan using
>> retailer_code_12390127_idx on tretailer_mst retailerlist  (cost=0.38..0.59
>> rows=1 width=684) (actual time=0.028..928.347 rows=221068 loops=1)

There seem to be rather serious discrepancies between rowcount estimates
and reality on the v13 installation.  Maybe an ANALYZE would help.

I'm also wondering why auto-analyze hasn't come along and improved
the situation.

			regards, tom lane