Avoid calling contrib/amcheck functions with relations that are
unsuitable for checking. Specifically, don't attempt verification of
temporary relations, or indexes whose pg_index entry indicates that the
index is invalid, or not ready.
These relations are not supported by any of the contrib/amcheck
functions, for reasons that are pretty fundamental. For example, the
implementation of REINDEX CONCURRENTLY can add its own "transient"
pg_index entries, which has rather unclear implications for the B-Tree
verification functions, at least in the general case -- so they just
treat it as an error. It falls to the amcheck caller (in this case
pg_amcheck) to deal with the situation at a higher level.
pg_amcheck now simply treats these conditions as additional "visibility
concerns" when it queries system catalogs. This is a little arbitrary.
It seems to have the least problems among any of the available
alternatives.
Author: Mark Dilger <mark.dilger@enterprisedb.com>
Reported-By: Alexander Lakhin <exclusion@gmail.com>
Reviewed-By: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Robert Haas <robertmhaas@gmail.com>
Bug: #17212
Discussion: https://postgr.es/m/17212-34dd4a1d6bba98bf@postgresql.org
Backpatch: 14-, where pg_amcheck was introduced.
d2bf06db37