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From: David G. Johnston <[email protected]>
To: Sbob <[email protected]>
Cc: Rui DeSousa <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: checking for a NULL date in a partitioned table kills performance
Date: Thu, 22 Aug 2024 17:01:37 -0700
Message-ID: <CAKFQuwZKTiS5b_Loe21p9rFBzR5XriHODPeocP40QAECTHEMkA@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
	<[email protected]>
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	<[email protected]>

On Thu, Aug 22, 2024 at 4:32 PM Sbob <[email protected]> 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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