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From: David Rowley <dgrowleyml@gmail.com>
Date: Tue, 24 Mar 2026 13:12:17 +1300
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 <CAApHDvrSSeLNWzQWWcLfZKWwHd=XocVs3abmTmvaSD_sx-dkNQ@mail.gmail.com>
Subject: Re: Fix "could not find memoization table entry"
To: Tender Wang <tndrwang@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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On Mon, 23 Mar 2026 at 19:30, Tender Wang <tndrwang@gmail.com> wrote:
> Recently, I encountered an error: could not find memoization table

> The hkeys returned by datum_image_hash() are different, so we can't
> find the entry in the hash table.
>
> In the datum_image_hash(), if typByVal is true, calling
> result = hash_bytes((unsigned char *) &value, sizeof(Datum));
>
> I think we should use typLen here, not sizeof(Datum).
> I tried this way and didn't encounter any errors again.

The Datum values should be the same. You can't just compare the lowest
attlen bytes of a Datum.

It looks to me like the bug is in hash_numeric(). Seems like it has no
idea what type it's meant to return. hash_numeric_extended() doesn't
seem to be much better.

Do you still get the ERROR after patching with the attached?

David

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