Re: Revert: Remove useless self-joins *and* -DREALLOCATE_BITMAPSETS make server crash, regress test fail.

David Rowley <dgrowleyml@gmail.com>

From: David Rowley <dgrowleyml@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Richard Guo <guofenglinux@gmail.com>, jian he <jian.universality@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-05-07T05:15:11Z
Lists: pgsql-hackers
On Tue, 7 May 2024 at 17:11, David Rowley <dgrowleyml@gmail.com> wrote:
> sjinf->syn_lefthand = bms_del_member(sjinf->syn_lefthand, relid);
>
> I've not looked, but I assumed the revert must have removed some
> common code that was added and reverted with SJE.

Yeah, before the revert, that did:

-       sjinf->syn_lefthand = replace_relid(sjinf->syn_lefthand, relid, subst);

That replace code seems to have always done a bms_copy()

-static Bitmapset *
-replace_relid(Relids relids, int oldId, int newId)
-{
-   if (oldId < 0)
-       return relids;
-
-   /* Delete relid without substitution. */
-   if (newId < 0)
-       return bms_del_member(bms_copy(relids), oldId);
-
-   /* Substitute newId for oldId. */
-   if (bms_is_member(oldId, relids))
-       return bms_add_member(bms_del_member(bms_copy(relids), oldId), newId);
-
-   return relids;
-}


David



Commits

  1. Make left-join removal safe under -DREALLOCATE_BITMAPSETS.

  2. Revert: Remove useless self-joins

  3. Remove mention of nchar