Date: Wed, 04 Feb 2026 19:22:22 +0900 (JST)
Message-Id: <20260204.192222.892684621512920290.ishii@postgresql.org>
To: assam258@gmail.com
Cc: jacob.champion@enterprisedb.com, david.g.johnston@gmail.com,
 vik@postgresfriends.org, er@xs4all.nl, peter@eisentraut.org,
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Subject: Re: Row pattern recognition
From: Tatsuo Ishii <ishii@postgresql.org>
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Hi Henson,

> Therefore, I believe it only makes sense to add explicit initialization
> for nfaStatesActive and nfaContextsActive, since these are the only two
> that release_partition() also explicitly resets.

That makes sense.

> Adding explicit
> initialization for all the cumulative statistics would be misleading,
> as it might suggest they get reset somewhere (which they don't).
> 
> ## Proposal for consistency
> 
> For consistency with release_partition(), I can add just the two
> per-partition counter initializations to ExecInitWindowAgg():
> 
>   /* Initialize NFA free lists for row pattern matching */
>   winstate->nfaContext = NULL;
>   winstate->nfaContextTail = NULL;
>   winstate->nfaContextFree = NULL;
>   winstate->nfaStateFree = NULL;
>   winstate->nfaLastProcessedRow = -1;
>   winstate->nfaStatesActive = 0;        // Add this
>   winstate->nfaContextsActive = 0;      // Add this
> 
> This would make both ExecInitWindowAgg() and release_partition()
> initialize the same set of per-partition NFA fields, making the code
> more uniform and easier to review. The cumulative statistics fields
> remain omitted in both functions, which correctly reflects that they
> are never reset.
> 
> Functionally, this change makes no difference since palloc0() already
> zeros these fields, but it improves code consistency and makes the
> per-partition vs. query-wide distinction clearer.
> 
> Would you like me to include this change in the next patch?

Yes, please.

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