Re: PG 15 (and to a smaller degree 14) regression due to ExprEvalStep size

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org, Nikita Glukhov <n.gluhov@postgrespro.ru>, Andrew Dunstan <andrew@dunslane.net>, David Rowley <dgrowleyml@gmail.com>
Date: 2022-06-16T23:37:14Z
Lists: pgsql-hackers
Andres Freund <andres@anarazel.de> writes:
> However, jsonexpr/EEOP_JSONEXPR is 296 bytes, and
> hashedscalararrayop/EEOP_HASHED_SCALARARRAYOP is 64 bytes, even though the
> limit is 40 bytes.

Oops.

> Maybe it's worth sticking a StaticAssert() for the struct size
> somewhere.

Indeed.  I thought we had one already.

> I'm a bit wary about that being too noisy, there are some machines with
> odd alignment requirements. Perhaps worth restricting the assertion to
> x86-64 + armv8 or such?

I'd put it in first and only reconsider if it shows unfixable problems.

			regards, tom lane



Commits

  1. JSON_TABLE: Add support for NESTED paths and columns

  2. Add basic JSON_TABLE() functionality

  3. Add SQL/JSON query functions

  4. Add soft error handling to some expression nodes

  5. Adjust populate_record_field() to handle errors softly

  6. Refactor code used by jsonpath executor to fetch variables

  7. Add more SQL/JSON constructor functions

  8. SQL/JSON: support the IS JSON predicate

  9. SQL/JSON: add standard JSON constructor functions

  10. Add static assertion ensuring sizeof(ExprEvalStep) <= 64 bytes

  11. Remove size increase in ExprEvalStep caused by hashed saops

  12. pgstat: reduce timer overhead by leaving timer running.

  13. expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.

  14. SQL/JSON query functions

  15. Speedup ScalarArrayOpExpr evaluation