Re: json/jsonb cleanup + FmgrInfo caching

On Sun, Oct 18, 2026 at 12:32 PM Manu <manuelreyesbravo(at)gmail(dot)com> wrote:
>
> shihao zhong <zhong950419(at)gmail(dot)com> writes:
> > Named composite types still have the problem. ALTER TYPE can add a
> > timestamptz after the index is built.
>
> I measured this on 18.6, 19rc1 and master, and it is broader than a mutable
> attribute: a pure structural change does it too, with no mutable type and no
> GUC. Adding a plain int attribute is enough.
>
> CREATE TYPE c1 AS (x int);
> CREATE TABLE t1 (v c1);
> INSERT INTO t1 VALUES (row(1));
> CREATE INDEX t1_i ON t1 ((json_array(v returning jsonb)));
> ALTER TYPE c1 ADD ATTRIBUTE y int;
> SELECT count(*) FROM t1
> WHERE json_array(v returning jsonb) =
> json_array(row(1, null)::c1 returning jsonb);
>
> The index scan returns 0 and a seq scan returns 1; REINDEX restores 1, so the

The attached patch should resolve these issues.

Note that float8out and float4out are considered immutable for PG19,
we can only change this in PG20.
see https://www.postgresql.org/message-id/19644-d6db3fb5e5ad92f4%40postgresql.org

--
jian
https://www.enterprisedb.com/