On Wed, 10 Nov 2004, Ramy M. Hassan wrote:
Oleg,
Thanks for your prompt reply.
Actually, I am able to create a new access method for testing and add an
operator class for the type "integer" using the new access method. Then
created a table with two integer fields, one indexed using the new access
method and the other using a btree index, and everything is ok so far. Even
using EXPLAIN statement for queries show that the indexes are used correctly
as they should.
I am using postgresql version 8.0.0beta3 from CVS.
I was wrong, Ramy. You could have several indices for the same type as soon
as they support different operations. I don't know if it's possible
to have them for the same operation but for different conditions.
Thanks
Ramy
-----Original Message-----
From: Oleg Bartunov [mailto:[EMAIL PROTECTED]
Sent: Wednesday, November 10, 2004 12:35 AM
To: Ramy M. Hassan; Pgsql Hackers
Cc: Teodor Sigaev; Walid G. Aref
Subject: Re: sp-gist porting to postgreSQL
Ramy,
glad to hear from you !
AFAIK, posgresql doesnt' supports several indices for the same type.
I think this is a problem of optimizer. Probably other hackers know
better. I forward your message to -hackers mailing list which is a
relevant place for GiST discussion.
regards,
Oleg
On Tue, 9 Nov 2004, Ramy M. Hassan wrote:
Dear Oleg and Teodor,
Thanks for offering help.
I have a design question for now.
Currently in the postgresql GiST implementation, I noticed that the way to
have a GiST based index is to define an operator class for a certain type
using GiST index. There is no new index type defined from the point of
view
of postgresql ( nothing is added to pg_am ). This means that for a certain
type there could only be one GiST based index. I mean that there is no way
in
the same server to use gist to implement an xtree index and a ytree for
the
same type even if they index different fields in different relations. is
that correct ?
What about doing it the other way ( I am talking about SP-GiST now ) , by
providing the extension writer with an API to use it to instantiate a
standalone SP-GiST based index ( for example trie index ) that has a
record
in the pg_am relation. In my point of view this would give more
flexibility,
and also would not require the extension writer to learn the postgresql
API (
maybe oneday SP-GiST will be ported to another database engine ) he will
just need to learn the SP-GiST API which will propably be less amount of
study (and this is what GiST and SP-GiST is all about if I correctly
understand ).
Please let me know your opinions regarding to this.
Thanks
Ramy
Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: [EMAIL PROTECTED], http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83
Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: [EMAIL PROTECTED], http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83
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