Horton

Re: On login trigger: take three

Zhihong Yu <zyu@yugabyte.com>

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From: Zhihong Yu <zyu@yugabyte.com>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Ivan Panchenko <wao@mail.ru>, Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Greg Nancarrow <gregn4422@gmail.com>, Teodor Sigaev <teodor@sigaev.ru>, Ibrar Ahmed <ibrar.ahmad@gmail.com>, vignesh C <vignesh21@gmail.com>, Pavel Stehule <pavel.stehule@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, a.sokolov@postgrespro.ru
Date: 2022-09-02T16:13:39Z
Lists: pgsql-hackers 
On Fri, Sep 2, 2022 at 8:37 AM Daniel Gustafsson <daniel@yesql.se> wrote:

> This had bitrotted a fair bit, attached is a rebase along with (mostly)
> documentation fixes.  0001 adds a generic GUC for ignoring event triggers
> and
> 0002 adds the login event with event trigger support, and hooks it up to
> the
> GUC such that broken triggers wont require single-user mode.  Moving the CF
> entry back to Needs Review.
>
> --
> Daniel Gustafsson               https://vmware.com/
>
> Hi,
For EventTriggerOnLogin():

+           LockSharedObject(DatabaseRelationId, MyDatabaseId, 0,
AccessExclusiveLock);
+
+           tuple = SearchSysCacheCopy1(DATABASEOID,
ObjectIdGetDatum(MyDatabaseId));
+
+           if (!HeapTupleIsValid(tuple))
+               elog(ERROR, "cache lookup failed for database %u",
MyDatabaseId);

Should the lock be taken after the check (HeapTupleIsValid) is done ?

Cheers

Commits

  1. Fix some typos in event trigger docs

  2. Use heap_inplace_update() to unset pg_database.dathasloginevt

  3. Remove the flaky check in event_trigger_login regression test

  4. Fix instable 006_login_trigger.pl test

  5. Add support event triggers on authenticated login

  6. Add GUC for temporarily disabling event triggers

  7. Fix typo in reference to __FreeBSD__.

  8. Restore robustness of TAP tests that wait for postmaster restart.

  9. Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.