Re: Invalid indexes should not consume update overhead

On Sun, Jul 17, 2016 at 4:41 AM, Tomasz Ostrowski
<tometzky+pg@ato.waw.pl> wrote:
> That wouldn't solve my problem, which is that I need a way to disable
> indexes before large update. I believe (but I'm not sure) that Oracle has
> this concept:
>         ALTER INDEX [INDEX_NAME] UNUSABLE;

I think that this must make the index unusable to the optimizer. The
idea being that you can see the impact of dropping the index without
actually doing so, reserving the ability to back out (mark the index
usable once more rather than actually dropping it) if it turns out
that the index is of some use.

If it simply made the index unusable while removing any ongoing
obligation for writes to maintain the index, then what's the point in
supporting this at all? You need to be able to mark it usable again.

--
Peter Geoghegan