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Re: Query planning around one key of a multi-column index - Mailing list pgsql-admin

From Wells Oliver
Subject Re: Query planning around one key of a multi-column index
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Msg-id CAOC+FBWzn-TK99tZNP4s=HkFk1qWr6QXGnqDarLCKrBK5g_tXA@mail.gmail.com
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In response to Re: Query planning around one key of a multi-column index  (Craig James <cjames@emolecules.com>)
Responses Re: Query planning around one key of a multi-column index
Re: Query planning around one key of a multi-column index
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But so are you guys!

Thanks, this is helpful.

Is it really always true that querying off any column that's not the first column of a multi-column index will NOT use that index?


On Wed, Dec 18, 2019 at 7:02 PM Craig James <cjames@emolecules.com> wrote:

On Wed, Dec 18, 2019 at 4:43 PM Wells Oliver <wells.oliver@gmail.com> wrote:
I've been using PG now for so many years and I don't have a solid concrete answer on this in my head, and I feel like I should: if I have a table with a multi-column index and I query on one of those columns (or some subset of those columns), will it use that index?

Is there more reading on this topic? I've always felt it's a little more complicated but I'm not quite sure.

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Craig A. James
Chief Technology Officer
eMolecules, Inc.
3430 Carmel Mountain Road, Suite 250
San Diego, CA 92121
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