Re: Improve search for missing parent downlinks in amcheck

On Tue, Apr 30, 2019 at 5:58 PM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> I will think about a simple fix, but after the upcoming point release.
> There is no hurry.

Attached draft patch uses RelationGetNumberOfBlocks() to size each of
the two Bloom filters that may be used by amcheck to perform
verification.

The basic heapallindexed Bloom filter is now sized based on the
conservative assumption that there must be *at least*
"RelationGetNumberOfBlocks() * 50" elements to fingerprint (reltuples
will continue to be used to size the basic heapallindexed Bloom filter
in most cases, though). The patch also uses the same
RelationGetNumberOfBlocks() value to size the downlink Bloom filter.
This second change will fix your problem very non-invasively.

I intend to backpatch this to v11 in the next few days.

--
Peter Geoghegan