Re: Adding REPACK [concurrently]

Hello!

On Fri, Oct 31, 2025 at 12:17 AM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> Here's a new installment of this series, v25, including the CONCURRENTLY
> part, which required some conflict fixes on top of the much-changed
> v24-0001 patch.

> * cluster.c
> * CLUSTER a table on an index. This is now also used for VACUUM FULL.

Should we add something about repack here?

> ii_ExclusinOps
typo here.

> * index is inserted into catalogs and needs to be built later on.
Now it is only in case concurrently == true

> * Build the index information for the new index. Note that rebuild of
> * indexes with exclusion constraints is not supported, hence there is no
> * need to fill all the ii_Exclusion* fields.

Now the function supports its in !concurrently mode. Should we fill
ii_Exclusion? Also, it says

> If !concurrently, ii_ExclusinOps is currently not needed.

But it is not clear - why not?

> newInfo = makeIndexInfo(oldInfo->ii_NumIndexAttrs,
> oldInfo->ii_NumIndexKeyAttrs,
> oldInfo->ii_Am,
> indexExprs,
> indexPreds,
> oldInfo->ii_Unique,
> oldInfo->ii_NullsNotDistinct,
> false, /* not ready for inserts */
> true,
> indexRelation->rd_indam->amsummarizing,
> oldInfo->ii_WithoutOverlaps);

Is it ok we pass isready == false if !concurrent?
Also, we pass concurrent == true even if concurrently == false - feels
strange and probably wrong.

> This difference does has no impact on XidInMVCCSnapshot().
Should it be "This difference has no impact"?

> * pgoutput_cluster.c
> * src/backend/replication/pgoutput_cluster/pgoutput_cluster.c
it is pgoutput_trepack.c :)

Best regards,
Mikhail.