Re: pgsql: Fix search_path to a safe value during maintenance operations.

On Sun, Jul 02, 2023 at 08:57:31PM -0700, Noah Misch wrote:
> Another dimension of compromise could be to make MAINTAIN affect fewer
> commands in v16.  Un-revert the part of commit 05e1737 affecting just the
> commands it still affects.  For example, limit MAINTAIN and the 05e1737
> behavior change to VACUUM, ANALYZE, and REINDEX.  Don't worry about VACUUM or
> ANALYZE failing under commit 05e1737, since they would have been failing under
> autovacuum since 2018.  A problem index expression breaks both autoanalyze and
> REINDEX, hence the inclusion of REINDEX.  The already-failing argument doesn't
> apply to CLUSTER or REFRESH MATERIALIZED VIEW, so those commands could join
> MAINTAIN in v17.

I'm open to compromise if others are, but I'm skeptical that folks will be
okay with too much fancy footwork this late in the game.

Anyway, IMO your argument could extend to CLUSTER and REFRESH, too.  If
we're willing to change behavior under the assumption that autovacuum
would've been failing since 2018, then why wouldn't we be willing to change
it everywhere?  I suppose someone could have been manually vacuuming with a
special search_path for 5 years to avoid needing to schema-qualify their
index expressions (and would then be surprised that CLUSTER/REFRESH no
longer work), but limiting MAINTAIN to VACUUM, etc. would still break their
use-case, right?

> From my reading of the objections, I think they're saying that commit 05e1737
> arrived too late and that MAINTAIN is unacceptable without commit 05e1737.  I
> think you'd conform to all objections by pushing the revert to v16 and pushing
> a roll-forward of commit 05e1737 to master.

Okay, I'll adjust my plans accordingly.

-- 
Nathan Bossart
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