Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 4511 invoked from network); 11 Mar 2011 00:58:59 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 11 Mar 2011 00:58:59 -0000 Received: (qmail 86777 invoked by uid 500); 11 Mar 2011 00:58:57 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 86749 invoked by uid 500); 11 Mar 2011 00:58:57 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 86738 invoked by uid 99); 11 Mar 2011 00:58:57 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 11 Mar 2011 00:58:57 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=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 alvinuw@gmail.com designates 209.85.213.44 as permitted sender) Received: from [209.85.213.44] (HELO mail-yw0-f44.google.com) (209.85.213.44) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 11 Mar 2011 00:58:50 +0000 Received: by ywi6 with SMTP id 6so1224477ywi.31 for ; Thu, 10 Mar 2011 16:58:29 -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=QfYHo1HmIerohc9BsxIHA8xdP4WwEuGVJO2ujAobWyQ=; b=Egfr/8L87WBSxpJvxl+AuUG8DPeGP/C3poRmbGx5ddAERf/epCl5RcQ9gBAMCk0Rrj oaAXG7o127RBM8HtPD/7AaqF2xdbameQ/w3EUdqfKvw9JuccjJ9I9z0PqcpfkuirqZCj xpElfPaOk3NUk4vrgS4FIWLqGPd8+V/7od4yQ= 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=kGDetLMCsxTyqlmOl8uGaeguMyeRtJyHRnidLaKP0qocyqbHxr6zThiH7pYiO3PbSt TgHlBILwDiQkH7SG61lNzjkR+Qr9q8gked3PtLhgiktzWYVV/wT6ABZfVwbGJdsGj6gD sBb3tVEbT1p0x036jwq+8sCywtPUnha2mPcCA= MIME-Version: 1.0 Received: by 10.150.115.17 with SMTP id n17mr1887243ybc.60.1299805108100; Thu, 10 Mar 2011 16:58:28 -0800 (PST) Received: by 10.147.136.16 with HTTP; Thu, 10 Mar 2011 16:58:28 -0800 (PST) In-Reply-To: References: Date: Thu, 10 Mar 2011 19:58:28 -0500 Message-ID: Subject: Re: Is secondary index consistent with its base table? From: Alvin UW To: user@cassandra.apache.org Content-Type: multipart/alternative; boundary=000e0cd5c44cbedf42049e2a751f X-Virus-Checked: Checked by ClamAV on apache.org --000e0cd5c44cbedf42049e2a751f Content-Type: text/plain; charset=ISO-8859-1 Thanks. Why secondary indexes are recommended for only attributes with low cardinality and they are not very useful for high cardinality values? 2011/3/7 Jonathan Ellis > It does, but this is an implementation detail subject to change (e.g., > the bitmap indexes being added do not). > > On Mon, Mar 7, 2011 at 10:55 AM, Alvin UW wrote: > > Thanks. > > > > Does Cassandra store secondary index with an extra CF? > > > > 2011/3/7 Jonathan Ellis > >> > >> Yes, this is guaranteed the same way single-row updates are guaranteed > >> to be atomic (the commitlog). > >> > >> On Mon, Mar 7, 2011 at 10:13 AM, Alvin UW wrote: > >> > Hello, > >> > > >> > I was wondering whether Secondary Index is consistent with its base > >> > table? > >> > How did you guarantee the consistency? > >> > > >> > Thanks > >> > > >> > Alvin > >> > > >> > >> > >> > >> -- > >> Jonathan Ellis > >> Project Chair, Apache Cassandra > >> co-founder of DataStax, the source for professional Cassandra support > >> http://www.datastax.com > > > > > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of DataStax, the source for professional Cassandra support > http://www.datastax.com > --000e0cd5c44cbedf42049e2a751f Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks.

Why secondary indexes are recommended for only attributes wi= th low cardinality and they are not very useful for high cardinality values= ?

2011/3/7 Jonathan Ellis <jbellis@gmail.com>
It does, but this= is an implementation detail subject to change (e.g.,
the bitmap indexes being added do not).

On Mon, Mar 7, 2011 at 10:55 AM, Alvin UW <alvinuw@gmail.com> wrote:
> Thanks.
>
> Does Cassandra store secondary index with an extra CF?
>
> 2011/3/7 Jonathan Ellis <jbell= is@gmail.com>
>>
>> Yes, this is guaranteed the same way single-row updates are guaran= teed
>> to be atomic (the commitlog).
>>
>> On Mon, Mar 7, 2011 at 10:13 AM, Alvin UW <alvinuw@gmail.com> wrote:
>> > Hello,
>> >
>> > I was wondering whether Secondary Index is consistent with it= s base
>> > table?
>> > How did you guarantee the consistency?
>> >
>> > Thanks
>> >
>> > Alvin
>> >
>>
>>
>>
>> --
>> Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder of DataStax, the source for professional Cassandra supp= ort
>> http://www.d= atastax.com
>
>



--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.c= om

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