Re: knngist - 0.8

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Alexander Korotkov <aekorotkov(at)gmail(dot)com>
Cc: teodor(at)sigaev(dot)ru, pgsql-hackers(at)postgresql(dot)org
Subject: Re: knngist - 0.8
Date: 2010-08-09 18:32:09
Message-ID: AANLkTin9QBrxbcjG4Dmbsv0u-xHEfqmQDSCo+PNRh1A0@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Sun, Aug 8, 2010 at 4:28 PM, Alexander Korotkov <aekorotkov(at)gmail(dot)com> wrote:
> In gist consitent method support only filtering strategies. For such
> strategies consistent method returns true if subtree can contain matching
> node and false otherwise. Knngist introduce also order by strategies. For
> filtering strategies knngist consistent method returns 0 if  subtree can
> contain matching node and -1 otherwise. For order by strategies knngist
> consistent method returns minimal possible distance in subtree. I think we
> can use consistent method with order by strategies not only for ordering but
> also for filtering. If query contain assertion that distance is less than
> some value, than we can call consistent method with order by strategy and
> compare result with query value in order to determine whether scan subtree.

I am not an expert on this code, but after thinking this over, I
believe you are correct and that this is a good point.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Bruce Momjian 2010-08-09 18:33:08 Re: dynamically allocating chunks from shared memory
Previous Message Robert Haas 2010-08-09 18:29:16 Re: Surprising dead_tuple_count from pgstattuple