Re: use of SPI by postgresImportForeignStatistics

On Fri, Jun 19, 2026 at 6:23 AM Corey Huinker <corey(dot)huinker(at)gmail(dot)com> wrote:
> Attached are two patches to remove SPI from the postgres_fdw.c, replaced by local C functions. The division into two patches is entirely for readability. Separately, each one represents a half-measure that would benefit no one. The first does the minimal changes needed to get the relation-stats to stop using SPI, and the second does the same for attribute stats, removes all vestiges of SPI from postgres_fdw.c, and adds some tests to make sure that a foreign table has the exact stats of the source loopback table.
>
> The function import_attribute_stats() is a bit parameter-happy, but that's mostly necessary. I left the non-key parameters as all type char* because that avoids even more "bool foo_isnull" parameters, and that allows the caller to not have to rework the various stat types into their corresponding C types (float, int4, float[], and the anyarrays that basically aren't cast-able by any client program anyway). I'm open to requiring the caller to use the right datatypes for some of the parameters, but as I said there is no way to "win" with the anyarrays, and even the pg_restore_attribute_stats() function falls back to type text for those.
>
> To be clear, this solves the SPI problem, but questions about the design of attribute_statistics_update() and relation_statistics_update() remain, but those concerns are now isolated within their respective files attribute_stats.c and relation_stats.c. The inefficiencies therein aren't really in a critical path, so if we wanted to leave them be until v20 they could, but if time allows I'd at least like try unwinding some of that. But first, let's get SPI out of postgres_fdw.c.

Ok, I'll review the patches.

Thanks!

Best regards,
Etsuro Fujita