Re: btree_gist: Fix NaN handling in float4 and float8 opclasses

Ewan Young <kdbase(dot)hack(at)gmail(dot)com> 于2026年6月17日周三 16:40写道：
>
> Hi,
>
> A GiST index on a float4/float8 column (via btree_gist) can silently
> omit rows containing NaN, returning different results from a sequential
> scan:
>
> CREATE EXTENSION btree_gist;
> CREATE TABLE t (a float8);
> INSERT INTO t SELECT 1 FROM generate_series(1, 1000);
> INSERT INTO t SELECT 'NaN' FROM generate_series(1, 1000);
> CREATE INDEX ON t USING gist (a);
>
> SET enable_seqscan = on;
> SELECT count(*) FROM t WHERE a = 'NaN'; -- 1000
> SET enable_seqscan = off;
> SELECT count(*) FROM t WHERE a = 'NaN'; -- 0 (wrong)
>

It seems the issue you reported is the same as [1].
Please double-check.

[1] https://www.postgresql.org/message-id/19501-3bff3bbc97f1e7c9%40postgresql.org

--
Thanks,
Tender Wang