Re: Row pattern recognition

> Hi Ishii-san,
>
> While reviewing the code, I noticed a potential improvement
> in 'register_reduced_frame_map()':
>
> diff --git a/src/backend/executor/nodeWindowAgg.c
> b/src/backend/executor/nodeWindowAgg.c
> index 5185ad40237..3a71c279945 100644
> --- a/src/backend/executor/nodeWindowAgg.c
> +++ b/src/backend/executor/nodeWindowAgg.c
> @@ -4770,7 +4770,7 @@ register_reduced_frame_map(WindowAggState *winstate,
> int64 pos, int val)
> if (pos < 0)
> elog(ERROR, "wrong pos: " INT64_FORMAT, pos);
>
> - if (pos > winstate->alloc_sz - 1)
> + while (pos > winstate->alloc_sz - 1)
> {
> realloc_sz = winstate->alloc_sz * 2;
>
> In practice, 'pos' is always sequential (0, 1, 2, ...),
> so the current 'if' works fine - doubling once is always
> sufficient for +1 increment.
>
> However, using 'while' would be more defensive, handling
> any theoretical case where 'pos' might jump by more than
> 2x the current size.
>
> It's a trivial change with no functional impact on normal
> operation, but makes the code more robust.
>
> What do you think?

Looks good improvement to me. Will merge into v41.

Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
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