Horton

Re: Add support for AT LOCAL

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Vik Fearing <vik@postgresfriends.org>, cary huang <hcary328@gmail.com>, pgsql-hackers@lists.postgresql.org
Date: 2023-10-16T03:02:45Z
Lists: pgsql-hackers 
Thomas Munro <thomas.munro@gmail.com> writes:
> On Mon, Oct 16, 2023 at 2:58 PM Michael Paquier <michael@paquier.xyz> wrote:
>> Another theory would be one of these weird compiler optimization issue
>> from xlc?  In recent history, there was 8d2a01ae12cd.

> Yeah, there are more like that too.  xlc 12.1 is dead (like the OS
> version it shipped with).  New versions are available on cfarm if we
> care about this target.  But I am conscious of the cosmic law that if
> you blame the compiler too soon you can cause the bug to move into
> your code...

I'm having a hard time not believing that this is a compiler bug.
Looking back at 8d2a01ae12cd and its speculation that xlc is overly
liberal about reordering code around sequence points ... I wonder
if it'd help to do this calculation in a local variable, and only
assign the final value to result->time ?  But we have to reproduce
the problem first.

			regards, tom lane

Commits

  1. Dodge a compiler bug affecting timetz_zone/timetz_izone.

  2. Back-patch test cases for timetz_zone/timetz_izone.

  3. Add regression test coverage for timetz_izone().

  4. Add support for AT LOCAL

  5. doc: Mention timezone(zone, time) in section for AT TIME ZONE

  6. Use HASH_BLOBS for xidhash.