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Re: Unexpected table size usage for small composite arrays - Mailing list pgsql-hackers

From David G. Johnston
Subject Re: Unexpected table size usage for small composite arrays
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Msg-id CAKFQuwY47deTv+txZvETGmtsdHUUDQ0aD3y3W1OMLDPrTcGTvA@mail.gmail.com
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In response to Re: Unexpected table size usage for small composite arrays  ("David G. Johnston" <david.g.johnston@gmail.com>)
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On Tue, Oct 22, 2024 at 4:42 PM David G. Johnston <david.g.johnston@gmail.com> wrote:
On Tue, Oct 22, 2024 at 4:40 PM Erik Sjoblom <sjoblom65@gmail.com> wrote:
I hear what you are saying Tom and what I have read says that it would take 24 + 12 x N bytes for the array.

Whatever you are reading, or your interpretation of it, is flawed.

Since you are posting to -hackers anyway (not that figuring this out from the user-facing documentation seems easy if possible at all...) here is what Tom is referring to.

https://github.com/postgres/postgres/blob/a0bff38d133ac95fb56bbd868a128bba95ec46c9/src/include/access/htup_details.h#L54

David J.

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