Re: Index Skip Scan - Mailing list pgsql-hackers

From Jesper Pedersen
Subject Re: Index Skip Scan
Date
Msg-id 4d469bf2-49ff-bc3d-a428-6c7b5d87d526@redhat.com
Whole thread Raw
In response to Re: Index Skip Scan  (Floris Van Nee <florisvannee@Optiver.com>)
Responses Re: Index Skip Scan
Re: Index Skip Scan
List pgsql-hackers
Hi,

On 6/5/19 3:39 PM, Floris Van Nee wrote:
> Thanks! I've verified that it works now.

Here is a rebased version.

> I was wondering if we're not too strict in some cases now though. Consider the following queries:

[snip]

> This is basically the opposite case - when distinct_pathkeys matches the filtered list of index keys, an index skip
scancould be considered. Currently, the user needs to write 'distinct m,f' explicitly, even though he specifies in the
WHERE-clausethat 'm' can only have one value anyway. Perhaps it's fine like this, but it could be a small improvement
forconsistency.
 
> 

I think it would be good to get more feedback on the patch in general 
before looking at further optimizations. We should of course fix any 
bugs that shows up.

Thanks for your testing and feedback !

Best regards,
  Jesper

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