From: Tom Lane <tgl@sss.pgh.pa.us>
To: Justin Pryzby <pryzby@telsasoft.com>
cc: Semen Yefimenko <semen.yefimenko@gmail.com>,
        Vijaykumar Jain <vijaykumarjain.github@gmail.com>,
        pgsql-performance@lists.postgresql.org
Subject: Re: Very slow Query compared to Oracle / SQL - Server
In-reply-to: <20210507161551.GT27406@telsasoft.com>
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Comments: In-reply-to Justin Pryzby <pryzby@telsasoft.com>
	message dated "Fri, 07 May 2021 11:15:51 -0500"
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Date: Fri, 07 May 2021 12:28:42 -0400
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Justin Pryzby <pryzby@telsasoft.com> writes:
> On Fri, May 07, 2021 at 05:57:19PM +0200, Semen Yefimenko wrote:
>> For testing purposes I set up a separate postgres 13.2 instance on windows.
>> To my surprise, it works perfectly fine. Also indexes, have about 1/4 of
>> the size they had on 12.6.

> In pg13, indexes are de-duplicated by default.
> But I suspect the performance is better because data was reload, and the
> smaller indexes are a small, additional benefit.

Index bloat is often a consequence of inadequate vacuuming.  You might
need to dial up autovacuum's aggressiveness to keep their sizes in check.

			regards, tom lane