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Re: Should we optimize the `ORDER BY random() LIMIT x` case? - Mailing list pgsql-hackers

From Nico Williams
Subject Re: Should we optimize the `ORDER BY random() LIMIT x` case?
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Msg-id aCezOeKRnvVUHml1@ubby
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In response to Re: Should we optimize the `ORDER BY random() LIMIT x` case?  (Tom Lane <tgl@sss.pgh.pa.us>)
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On Fri, May 16, 2025 at 09:01:50AM -0400, Tom Lane wrote:
> Seems to me the obvious answer is to extend TABLESAMPLE (or at least, some
> of the tablesample methods) to allow it to work on a subquery.

The key here is that we need one bit of state between rows: the count of
rows seen so far.

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