Re: BUG #17212: pg_amcheck fails on checking temporary relations

> On Oct 4, 2021, at 6:19 PM, Peter Geoghegan <pg@bowt.ie> wrote:
>
> I don't see what the point of this example is.

It doesn't matter.

I am changing pg_amcheck to filter out indexes as you say.  Since the btree check should no longer error in these
cases,the issue of pg_amcheck exit(2) sorts itself out without further code changes. 

I am changing verify_heapam to skip unlogged tables during recovery.  In testing, checking such a table results in a
simplenotice: 

  NOTICE:  cannot verify unlogged relation "u_tbl" during recovery, skipping

While testing, I also created an index on the unlogged table and checked that index using bt_index_parent_check, and
wassurprised that checking it using bt_index_parent_check raises an error: 

  ERROR:  cannot acquire lock mode ShareLock on database objects while recovery is in progress
  HINT:  Only RowExclusiveLock or less can be acquired on database objects during recovery.

It doesn't get as far as btree_index_mainfork_expected().  So I am changing pg_amcheck to filter out indexes when
pg_is_in_recovery()is true and relpersistence='u'.  Does that sound right to you? 

—
Mark Dilger
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company