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Re: checking for a NULL date in a partitioned table kills performance - Mailing list pgsql-admin

From David G. Johnston
Subject Re: checking for a NULL date in a partitioned table kills performance
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Msg-id CAKFQuwZKTiS5b_Loe21p9rFBzR5XriHODPeocP40QAECTHEMkA@mail.gmail.com
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In response to Re: checking for a NULL date in a partitioned table kills performance  (Sbob <sbob@quadratum-braccas.com>)
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On Thu, Aug 22, 2024 at 4:32 PM Sbob <sbob@quadratum-braccas.com> wrote:

29 million of the 32 million rows in the table have NULL for contract_date


Your expectation that this query should use an index is flawed.  Indexes are for highly selective queries.  Finding nulls on that table is not selective.

David J.

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