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From: Matheus Alcantara <[email protected]>
To: Ilia Evdokimov <[email protected]>
To: Tatsuya Kawata <[email protected]>
To: David Geier <[email protected]>
Cc: Chengpeng Yan <[email protected]>
Cc: [email protected] <[email protected]>
Subject: Re: Hash-based MCV matching for large IN-lists
Date: Tue, 24 Feb 2026 16:32:15 -0300
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
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	<CAHza6qdAH99C0xa27YDTixiNVFa99j90QYquUPAxL0JwahmggA@mail.gmail.com>
	<[email protected]>

Hi, thanks for working on this!

On Wed Feb 18, 2026 at 9:48 AM -03, Ilia Evdokimov wrote:
> I've fixed all the comments raised above and updated the v5 patch.
>

Here are some comments regarding v5 patch:

On scalararraysel() we have:

+				ReleaseVariableStats(vardata);
+
+				if (s1 >= 0.0)
+					return s1;

I'm wondering if we also should call ReleaseVariableStats() on the early
return?

+					if (!useOr && elem_nulls[i])
+					{
+						pfree(elem_values);
+						pfree(elem_nulls);
+						pfree(elem_const);
+
+						return (Selectivity) 0.0;
+					}

------------------

On scalararray_mcv_hash_match() free_attstatsslot() is called only on
if (have_mcvs && OidIsValid(hashLeft) && OidIsValid(hashRight)),
perhaps it should be moved outside the if condition?

+	if (have_mcvs && OidIsValid(hashLeft) && OidIsValid(hashRight))
+	{
+       ...

+		MCVHashTable_destroy(hashTable);
+		free_attstatsslot(&sslot);
+	}
+
+	return selec;


------------------

typo: "all elements are const"

+ *              array is NULL if all elemnets is const.

------------------

It's worth adding on scalararray_mcv_hash_match() an early return when
num_elems == 0? I imagine that this can happens, e.g "WHERE a =
ANY(array[]::int[]);". In this case the function should still execute
completely?

--
Matheus Alcantara
EDB: https://www.enterprisedb.com

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