Re: disabling an index without deleting it? - Mailing list pgsql-performance

From Scott Marlowe
Subject Re: disabling an index without deleting it?
Date
Msg-id dcc563d10802261257h6abfbc92x62a7569b8610ecc4@mail.gmail.com
Whole thread Raw
In response to disabling an index without deleting it?  ("Peter Koczan" <pjkoczan@gmail.com>)
Responses Re: disabling an index without deleting it?  ("Joshua D. Drake" <jd@commandprompt.com>)
List pgsql-performance
On Tue, Feb 26, 2008 at 2:46 PM, Peter Koczan <pjkoczan@gmail.com> wrote:
> This might be a weird question...is there any way to disable a
>  particular index without dropping it?
>
>  There are a few queries I run where I'd like to test out the effects
>  of having (and not having) different indexes on particular query plans
>  and performance. I'd really prefer not to have to drop and ultimately
>  recreate a particular index, as some of the data sets are quite large.
>
>  So, is there any way to do this, or at least mimic this sort of behavior?

The brick to the head method would use set enable_indexscan = off;
However, you can delete an index without actually deleting it like so:

begin;
drop index abc_dx;
select ....
rollback;

and viola, your index is still there.  note that there are likely some
locking issues with this, so be careful with it in production.  But on
a test box it's a very easy way to test various indexes.

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