Re: BUG #5727: Indexes broken in streaming replication

Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>> * Operations on hash indexes are not presently WAL-logged, so replay will not update these indexes. Hash indexes will not be used for query plans during recovery.

> The initial patch indeed had a special-case in the planner to ignore
> hash indexes during hot standby, but it was left out because the lack of
> WAL-logging is a general problem with hash indexes, not a hot standby
> issue.

Yeah, and also the index would still be broken after the slave exits hot
standby and becomes live; so that hack didn't cure the problem anyway.

> I'd be tempted to remove that caveat altogether for the same
> reason, but it's probably good to have that note there and just remove
> the sentence about query plans:

Agreed.

regards, tom lane