Re: index-only scans - Mailing list pgsql-hackers

From Jeff Janes
Subject Re: index-only scans
Date
Msg-id CAMkU=1wPQkZ3yWd9kLCL18UHMDiTGJ0+4mUaa-FuMGYKQWkNZQ@mail.gmail.com
Whole thread Raw
In response to Re: index-only scans  (Jeff Janes <jeff.janes@gmail.com>)
List pgsql-hackers
On Sat, Oct 15, 2011 at 2:16 PM, Jeff Janes <jeff.janes@gmail.com> wrote:
> On Fri, Oct 7, 2011 at 11:40 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Robert Haas <robertmhaas@gmail.com> writes:
>>> Please find attached a patch implementing a basic version of
>>> index-only scans.
>>
>> I'm making some progress with this, but I notice what seems like a
>> missing feature: there needs to be a way to turn it off.  Otherwise
>> performance comparisons will be difficult to impossible.
>>
>> The most obvious solution is a planner control GUC, perhaps
>> "enable_indexonlyscan".  Anyone object, or want to bikeshed the name?
>>
>
> Currently I can't force an indexonlyscan over an indexscan, because of
> the way the enable_* variables work.

OK, scratch that.  I must have been using the wrong query (for
which the index was not covering), as I can't reproduce the
behavior nor looking at the code can I see how it could have
occurred in the first place.

Cheers,

Jeff


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