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

On 2014-11-01 14:45:47 -0400, Andrew Dunstan wrote:
> 
> On 11/01/2014 02:34 PM, Andres Freund wrote:
> >>Yeah, if we were trying to duplicate the behavior of indisvalid, there'd
> >>need to be a way to detect the invalid index at plan time and not use it.
> >>But I'm not sure that that's actually an improvement from the user's
> >>standpoint: what they'd see is queries suddenly, and silently, performing
> >>a lot worse than they expect.  An explicit complaint about the necessary
> >>REINDEX seems more user-friendly from where I sit.
> >A REINDEX is imo unlikely to be acceptable. It takes long (why would you
> >bother on a small table?) and locks the relation/indexes.
> 
> 
> It's a bit of a pity we don't have REINDEX CONCURRENTLY.

We essentially don't have it because people opined towards the end of
9.4 that a brief (as in two pg_class updates) AccessExclusive lock
window makes the feature moot. I still think that's quite heavily
disregarding the practial reality.
Luckily opinion seems to have shifted a bit again.

It'd also be really helpful if REINDEX CONCURRENTLY had a way to only
reindex invalid indexes. But that probably is just a smop.

Greetings,

Andres Freund

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