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Posted to derby-dev@db.apache.org by Nirmal Fernando <ni...@gmail.com> on 2011/01/19 17:36:09 UTC
Using Bitmap Indexes
Hi All,
Does Derby already use bitmap indexes? If not aren't using bitmap indexes
improve performance?
Thanks!
--
Best Regards,
Nirmal
C.S.Nirmal J. Fernando
Department of Computer Science & Engineering,
Faculty of Engineering,
University of Moratuwa,
Sri Lanka.
Blog: http://nirmalfdo.blogspot.com/
Re: Using Bitmap Indexes
Posted by Rick Hillegas <ri...@oracle.com>.
Hi Nirmal,
Derby does not use bitmap indexes. Some of the value of bitmap indexes
can be achieved by building regular btree indexes on generated columns,
where the generation clauses are boolean valued expressions built up out
of other columns in the row.
Regards,
-Rick
On 1/19/11 8:36 AM, Nirmal Fernando wrote:
> Hi All,
>
> Does Derby already use bitmap indexes? If not aren't using bitmap
> indexes improve performance?
>
> Thanks!
>
> --
> Best Regards,
> Nirmal
>
> C.S.Nirmal J. Fernando
> Department of Computer Science & Engineering,
> Faculty of Engineering,
> University of Moratuwa,
> Sri Lanka.
>
> Blog: http://nirmalfdo.blogspot.com/
>
Re: Using Bitmap Indexes
Posted by Nirmal Fernando <ni...@gmail.com>.
Hi Rick, thanks for your reply!
Hi Lily,
On Wed, Jan 19, 2011 at 10:23 PM, Lily Wei <li...@yahoo.com> wrote:
> Hi Nirmal:
>
> I know there were a lot of talks about bitmap indexes from my other
> prior company.
>
> I remember the conclusion is depending on the data type. For simple data
> type (int, etc), it shall.
>
> For complex data type (blob, etc), it depending on whether i/o can be
> decrease. Well, there might be other angle to
>
> look at the problem.
>
Thanks for the information.
>
>
> Are you thinking of a project for optimizer? May I make a suggestion?
> How about columnar search? It has been proven to be one of the best
> methods so far. Infobright is also using it to build their index and they
> are an open source database too.
>
I will look into columnar search Lily, thanks for the suggestion!
>
>
>
>
> Hope this help,
>
> Lily
>
> ------------------------------
> *From:* Nirmal Fernando <ni...@gmail.com>
> *To:* derby-dev@db.apache.org
> *Sent:* Wed, January 19, 2011 8:36:09 AM
> *Subject:* Using Bitmap Indexes
>
> Hi All,
>
> Does Derby already use bitmap indexes? If not aren't using bitmap indexes
> improve performance?
>
> Thanks!
>
> --
> Best Regards,
> Nirmal
>
> C.S.Nirmal J. Fernando
> Department of Computer Science & Engineering,
> Faculty of Engineering,
> University of Moratuwa,
> Sri Lanka.
>
> Blog: http://nirmalfdo.blogspot.com/
>
>
>
--
Best Regards,
Nirmal
C.S.Nirmal J. Fernando
Department of Computer Science & Engineering,
Faculty of Engineering,
University of Moratuwa,
Sri Lanka.
Blog: http://nirmalfdo.blogspot.com/
Re: Using Bitmap Indexes
Posted by Lily Wei <li...@yahoo.com>.
Hi Nirmal:
I know there were a lot of talks about bitmap indexes from my other prior
company.
I remember the conclusion is depending on the data type. For simple data type
(int, etc), it shall.
For complex data type (blob, etc), it depending on whether i/o can be decrease.
Well, there might be other angle to
look at the problem.
Are you thinking of a project for optimizer? May I make a suggestion? How
about columnar search? It has been proven to be one of the best methods so far.
Infobright is also using it to build their index and they are an open source
database too.
Hope this help,
Lily
________________________________
From: Nirmal Fernando <ni...@gmail.com>
To: derby-dev@db.apache.org
Sent: Wed, January 19, 2011 8:36:09 AM
Subject: Using Bitmap Indexes
Hi All,
Does Derby already use bitmap indexes? If not aren't using bitmap indexes
improve performance?
Thanks!
--
Best Regards,
Nirmal
C.S.Nirmal J. Fernando
Department of Computer Science & Engineering,
Faculty of Engineering,
University of Moratuwa,
Sri Lanka.
Blog: http://nirmalfdo.blogspot.com/