From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
cc: Pg Docs <pgsql-docs@lists.postgresql.org>,
        Edson Richter <edsonrichter@hotmail.com>
Subject: Re: Partitioning docs (was Re: Range partitioning and overlap)
In-reply-to: <417734.1605323748@sss.pgh.pa.us>
References: 
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 <398613.1605301084@sss.pgh.pa.us> <414580.1605320014@sss.pgh.pa.us>
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 <417734.1605323748@sss.pgh.pa.us>
Comments: In-reply-to Tom Lane <tgl@sss.pgh.pa.us>
	message dated "Fri, 13 Nov 2020 22:15:48 -0500"
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Date: Sat, 14 Nov 2020 13:11:29 -0500
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I wrote:
> "David G. Johnston" <david.g.johnston@gmail.com> writes:
>> I am curious as to your thoughts on unique indexes and whether/how to
>> better incorporate advice regarding the use of ON CONFLICT with
>> partitioning [1] vis-a-vis the overview's claim of:
>> "The partitioning substitutes for leading columns of indexes, reducing
>> index size and making it more likely that the heavily-used parts of the
>> indexes fit in memory" [2]

> Possibly a better way to write that claim is that partitioning can
> substitute for the upper levels of a huge index, rather than "leading
> columns" per se.  That way of looking at it is still sensible when
> a partition covers more than one value of the key column.

I changed it like that and pushed.

			regards, tom lane