Re: Let's drop two obsolete features which are bear-traps for novices

On 2014-11-01 14:39:21 -0400, Tom Lane wrote:
> Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> > A REINDEX is imo unlikely to be acceptable. It takes long (why would you
> > bother on a small table?) and locks the relation/indexes.
>
> I think the goalposts just took a vacation to Acapulco.

I think that might be caused by a misunderstanding.

> What exactly do you think is going to make a crashed unlogged index valid
> again without a REINDEX? Certainly the people who are currently using
> hash indexes in the way Andrew describes are expecting to have to REINDEX
> them after a crash.

Obviously that individual index needs to be recreated. What I mean is
that I don't think it'll be acceptable that the table essentially can't
be queried before that's done. The situations in which I'd found
unlogged indexes useful is where there's some indexes are critical for
the OLTP business (those would continue to be logged), but some other
large ones are for things that aren't absolutely essential. Reports and
such.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services