Re: BUG #6200: standby bad memory allocations on SELECT

I wrote:
> Hm.  The stack trace is definitive that it's finding the bad data in a
> tuple that it's trying to print to the client, not in an index.

BTW, after a bit more reflection it occurs to me that it's not so much
that the data is necessarily *bad*, as that it seemingly doesn't match
the tuple descriptor that the backend's trying to interpret it with.
(In particular, the reported symptom would be consistent with finding
a small integer constant at a place where the descriptor expects to find
a variable-length field.)  So that opens up a different line of thought
about how those could get out of sync on a standby.  Are you in the
habit of issuing ALTER TABLE commands to add/delete/change columns on
these tables?  In fact, is there any DDL whatsoever going on around the
time these failures happen?

            regards, tom lane