Re: API stability [was: pgsql: Fix possible recovery trouble if TRUNCATE overlaps a checkpoint.] - Mailing list pgsql-hackers

From Robert Haas
Subject Re: API stability [was: pgsql: Fix possible recovery trouble if TRUNCATE overlaps a checkpoint.]
Date
Msg-id CA+TgmoaVwQj_nG-jPB8O=t8=h-QBoF2U+tKviv8BT8unfTEZiw@mail.gmail.com
Whole thread Raw
In response to API stability [was: pgsql: Fix possible recovery trouble if TRUNCATE overlaps a checkpoint.]  (Markus Wanner <markus.wanner@enterprisedb.com>)
Responses Re: API stability [was: pgsql: Fix possible recovery trouble if TRUNCATE overlaps a checkpoint.]  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Tue, Apr 5, 2022 at 9:02 AM Markus Wanner
<markus.wanner@enterprisedb.com> wrote:
> And for this specific case: Is it worth reverting this change and
> applying a fully backwards compatible fix, instead?

I think it's normally our policy to avoid changing definitions of
accessible structs in back branches, except that we allow ourselves
the indulgence of adding new members at the end or in padding space.
So what would probably be best is if, in the back-branches, we changed
"delayChkpt" back to a boolean, renamed it to delayChkptStart, and
added a separate Boolean called delayChkptEnd. Maybe that could be
added just after statusFlags, where I think it would fall into padding
space.

I think as the person who committed that patch I'm on the hook to fix
this if nobody else would like to do it, but let me ask whether
Kyotaro Horiguchi would like to propose a patch, since the original
patch did, and/or whether you would like to propose a patch, as the
person reporting the issue.

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



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