Return-Path: Delivered-To: apmail-db-derby-dev-archive@www.apache.org Received: (qmail 72752 invoked from network); 21 Jan 2011 04:57:17 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 21 Jan 2011 04:57:17 -0000 Received: (qmail 57806 invoked by uid 500); 21 Jan 2011 04:57:16 -0000 Delivered-To: apmail-db-derby-dev-archive@db.apache.org Received: (qmail 57585 invoked by uid 500); 21 Jan 2011 04:57:14 -0000 Mailing-List: contact derby-dev-help@db.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: Delivered-To: mailing list derby-dev@db.apache.org Received: (qmail 57573 invoked by uid 99); 21 Jan 2011 04:57:13 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 21 Jan 2011 04:57:13 +0000 X-ASF-Spam-Status: No, hits=3.7 required=10.0 tests=FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of nirmal070125@gmail.com designates 209.85.215.44 as permitted sender) Received: from [209.85.215.44] (HELO mail-ew0-f44.google.com) (209.85.215.44) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 21 Jan 2011 04:57:05 +0000 Received: by ewy8 with SMTP id 8so753954ewy.31 for ; Thu, 20 Jan 2011 20:56:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=ySWCJ7ZBGKqIfahZipDaaOCk0ycr8ew7GgsTblhgaKo=; b=DLZoWlZCRIc7EFgWpGDUPzAgYAieKfnrEFfi0opABbndnkfYtda6vAhKyWLw7NfZ8r 7qIUaNFpdJNQwxi2HjkXYd1tFATXiVxy3CTgMGbA2ivR1rrAh3Wq6IvEbvqGYDASX7gB OWCH75lDjczQ2rB/RhKoziz0hYBWEDCoL0wMI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=VtDoKReAPcgngnYAUcc9fIRpa3wBYtsiJRRTISbaqR9jsWTMEkO8Bty5Ajvr23YOWh XPQZrW79aUezBafryLcMjHPq2JEmGJx4SgiRy60SRY604f/ecYyxbcjScNp/SWwncQjh cmyr9Tf/wdB1v0aWAcJFW17vILCr5mK2V7his= MIME-Version: 1.0 Received: by 10.14.14.65 with SMTP id c41mr203155eec.16.1295585804949; Thu, 20 Jan 2011 20:56:44 -0800 (PST) Received: by 10.14.52.12 with HTTP; Thu, 20 Jan 2011 20:56:44 -0800 (PST) In-Reply-To: <898473.23156.qm@web65715.mail.ac4.yahoo.com> References: <898473.23156.qm@web65715.mail.ac4.yahoo.com> Date: Fri, 21 Jan 2011 10:26:44 +0530 Message-ID: Subject: Re: Using Bitmap Indexes From: Nirmal Fernando To: derby-dev@db.apache.org Content-Type: multipart/alternative; boundary=0016e65b54c6ae194f049a541312 X-Virus-Checked: Checked by ClamAV on apache.org --0016e65b54c6ae194f049a541312 Content-Type: text/plain; charset=ISO-8859-1 Hi Rick, thanks for your reply! Hi Lily, On Wed, Jan 19, 2011 at 10:23 PM, Lily Wei 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 > *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/ --0016e65b54c6ae194f049a541312 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Rick, thanks for your reply!

Hi Lily,

On Wed, Jan 19, 2011 at 10:23 PM, Lily Wei <lilywei@yahoo.com> wrote:

H= i Nirmal:

=A0=A0 =A0 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=A0

look at the problem.


Thanks for the information.

=A0=A0 =A0=A0

=A0=A0 =A0 Are you thinking of a project for optimizer? May I make a suggestion? How about columnar search?=A0 It has been proven to be one of the best methods so far. Infobright is also using it to build the= ir index and they are=A0an open source database too.


I will look into columnar search Lily, thanks for = the suggestion!
=A0

=A0

=A0

Hope this help,

Lily


From: Nirmal Fernando <nirmal070125@gmail.com>= ;
To: derby-dev@db.apache.org
Sent: Wed, January 19, 2011 8:3= 6:09 AM
Subject: Using Bitmap Inde= xes

Hi All,

Does Derby already use bitmap indexes? If not aren't usi= ng 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.




--
Best Regard= s,
Nirmal

C.S.Nirmal J. Fernando
Department of Computer Scienc= e & Engineering,
Faculty of Engineering,
University of Moratuwa,<= br> Sri Lanka.


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