Horton

Re: race condition in pg_class

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Noah Misch <noah@leadboat.com>
Cc: Michael Paquier <michael@paquier.xyz>, pgsql-hackers@postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>, Smolkin Grigory <smallkeen@gmail.com>
Date: 2024-06-12T18:08:31Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Replace tests of ALTER DATABASE RESET TABLESPACE.

  2. meson: Flush stdout in testwrap

  3. Fix catcache invalidation of a list entry that's being built

  4. Stop reading uninitialized memory in heap_inplace_lock().

  5. Fix use of uninitialized value in previous commit.

  6. Back-patch "Refactor code in tablecmds.c to check and process tablespace moves"

  7. Fix data loss at inplace update after heap_update().

  8. For inplace update durability, make heap_update() callers wait.

  9. Warn if LOCKTAG_TUPLE is held at commit, under debug_assertions.

  10. Don't lose partitioned table reltuples=0 after relhassubclass=f.

  11. Fix new assertion for MERGE view_name ... DO NOTHING.

  12. Remove configuration-dependent output from new inplace-inval test.

  13. AccessExclusiveLock new relations just after assigning the OID.

  14. Cope with inplace update making catcache stale during TOAST fetch.

  15. Expand comments and add an assertion in nodeModifyTable.c.

  16. Improve test coverage for changes to inplace-updated catalogs.

  17. Lock before setting relhassubclass on RELKIND_PARTITIONED_INDEX.

  18. Lock owned sequences during ALTER TABLE SET { LOGGED | UNLOGGED }.

  19. Make TAP todo_start effects the same under Meson and prove_check.

  20. Add an injection_points isolation test suite.

  21. Add wait event type "InjectionPoint", a custom type like "Extension".

  22. Create waitfuncs.c for pg_isolation_test_session_is_blocked().

  23. Rework planning and execution of UPDATE and DELETE.

On Wed, Jun 12, 2024 at 1:54 PM Noah Misch <noah@leadboat.com> wrote:
> If I were making a list of changes always welcome post-beta, it wouldn't
> include adding wait event types.  But I don't hesitate to add one if it
> unblocks a necessary test for a bug present in all versions.

However, injection points themselves are not present in all versions,
so even if we invent a new wait-event type, we'll have difficulty
testing older versions, unless we're planning to back-patch all of
that infrastructure, which I assume we aren't.

Personally, I think the fact that injection point wait events were put
under Extension is a design mistake that should be corrected before 17
is out of beta.

> Here's what I'm reading for each person's willingness to tolerate each option:
>
> STRATEGY                        | Paquier | Misch | Haas
> --------------------------------------------------------
> new "Injection Point" wait type | maybe   | yes   | yes
> INJECTION_POINT(...) naming     | yes     | yes   | unknown
> isolation spec says event names | yes     | no    | unknown
>
> Corrections and additional strategy lines welcome.  Robert, how do you judge
> the lines where I've listed you as "unknown"?

I'd tolerate INJECTION_POINT() if we had no other option but I think
it's clearly inferior. Does the last line refer to putting the
specific wait event names in the isolation spec file? If so, I'd also
be fine with that.

-- 
Robert Haas
EDB: http://www.enterprisedb.com