Re: pgsql: Introduce hash_search_with_hash_value() function

On Wed, Aug 7, 2024 at 1:34 PM Pavel Stehule <pavel.stehule@gmail.com> wrote:
> st 7. 8. 2024 v 12:22 odesílatel Alexander Korotkov <aekorotkov@gmail.com> napsal:
>> Thank you.
>> Please see 40064a8ee1 takes special efforts to match HTAB hash
>> function to syscache hash function.  By default, their hash values
>> don't match and you can't simply use syscache hash value to search
>> HTAB.  This probably should be mentioned in the header comment of
>> hash_seq_init_with_hash_value().
>
>
> yes, enhancing doc should be great + maybe assert

Please check the patch, which adds a caveat to the function header
comment.  I don't particularly like an assert here, because there
could be use-cases besides syscache callbacks, which could legally use
default hash function.

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Regards,
Alexander Korotkov
Supabase