Hi Manu,
v6 looks good to me. The child CHECK case, VALIDATE CONSTRAINT and
sql_drop all leave 0 stale entries now. One small thing.
ATSetTableSpaceCopyIndexes() also runs for ALTER INDEX, so a plain
ALTER INDEX SET TABLESPACE in a pipeline now commits on its own.
Maybe only call it for tables and matviews.
I recently got interested in replication lag with physical
replication, so I also looked at the replay side on a standby.
A plain top-level ALTER costs the same as master. In a transaction
block it costs more.
WAL size. The index copy is logged page by page, so the extra WAL
is the size of the indexes. Given they are mostly FPI, I think it is okay for
replicas to quickly catch up.
AccessExclusiveLock. Each index now gets one too, so one more lock
record per index goes to the standby. I think that is okay. The
table already has that lock, and queries lock the table before its
indexes, so nobody new is blocked.
Thanks,
Shihao
