Return-Path: X-Original-To: apmail-cassandra-user-archive@www.apache.org Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id C2587105A6 for ; Mon, 2 Sep 2013 15:50:21 +0000 (UTC) Received: (qmail 20449 invoked by uid 500); 2 Sep 2013 15:50:19 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 20428 invoked by uid 500); 2 Sep 2013 15:50:19 -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 20420 invoked by uid 99); 2 Sep 2013 15:50:18 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 02 Sep 2013 15:50:18 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of edlinuxguru@gmail.com designates 209.85.128.52 as permitted sender) Received: from [209.85.128.52] (HELO mail-qe0-f52.google.com) (209.85.128.52) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 02 Sep 2013 15:50:14 +0000 Received: by mail-qe0-f52.google.com with SMTP id a11so2231554qen.25 for ; Mon, 02 Sep 2013 08:49:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=kVhaBqojmdHkK3x9dUd22G+74OgomRJDddprG4XqFM4=; b=J255kGZrf5d0HcOeGqVWTSn5k536Lm0RaZLRsXZkM67zhm1sUO6TQcX1+hDsL/7TSC 8Z0mDs2QIDu+XBFagZBSXWSaMB9UyOkzUVJmg9IpWAkU/4MAaUL8S6KOQFA8L+FbbBg4 ji5MfkhEUeQsGuoQC8jMGsBYKJXhL+RdFtYU3UcrS6f3P2JAVvHj0cYnifhl71oVfCnD Iqkp8f7vGiBlmuiziyVklleADhcKlcUoYQoYF5Y3rCG4rMK2N8iJTN6M4t4spRNjUwpc h1ABXGhFYY3nR7t/Y8Gn+ecNM0FEfLaDy9SgoryeTx7SA2t1GdFj7K0v3FwQBzv45PAA EjhQ== MIME-Version: 1.0 X-Received: by 10.49.94.66 with SMTP id da2mr2299601qeb.96.1378136993931; Mon, 02 Sep 2013 08:49:53 -0700 (PDT) Received: by 10.49.96.69 with HTTP; Mon, 2 Sep 2013 08:49:53 -0700 (PDT) In-Reply-To: References: Date: Mon, 2 Sep 2013 11:49:53 -0400 Message-ID: Subject: Re: Does collection in CQL3 have certain limits? From: Edward Capriolo To: "user@cassandra.apache.org" Content-Type: multipart/alternative; boundary=047d7b621a0ef9c2bf04e56885c2 X-Virus-Checked: Checked by ClamAV on apache.org --047d7b621a0ef9c2bf04e56885c2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable I believe CQL has to fetch and transport the entire row, so if it contains a collection you transmit the entire collection. C* is mostly about low latency queries and as the row gets larger keeping low latency becomes impossible. Collections do not support a large number of columns, they were not designed to do that. IMHO If you are talking about 2K + columns collections are not for you use old-school c* wide rows. On Mon, Sep 2, 2013 at 10:36 AM, Keith Wright wrote: > I know that the size is limited to max short (~32k) because when deseria= lizing the response from the server, the first item returned is the number = of items and its a short. That being said you could likely handle this by = looking for the overflow and allowing double max short. > > Vikas Goyal wrote: > > > As there are two ways to support wide rows in CQL3..One is to use > composite keys and another is to use collections like Map, List and Set. > The composite keys method can have millions of columns (transposed to > rows).. This is solving some of our use cases. > > However, if we use collections, I want to know if there is a limit that > the collections can store a certain number/amount of data (Like earlier > with Thrift C* supports up-to 2 billion columns in a row) > > > Thanks, > > Vikas Goyal > --047d7b621a0ef9c2bf04e56885c2 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
I believe CQL has to fetch and transport the entire r= ow, so if it contains a collection you transmit the entire collection. C* i= s mostly about low latency queries and as the row gets larger keeping low l= atency becomes impossible.

Collections do not support a large number of columns, they were n= ot designed to do that. IMHO If you are talking about 2K + columns collecti= ons are not for you use old-school c* wide rows.


On Mon, Sep 2, 2013 at 10:36 AM, Keith W= right <kwright@nanigans.com> wrote:
I k=
now that the size is limited to max short (~32k) because when deserializing=
 the response from the server, the first item returned is the number of ite=
ms and its a short.  That being said you could likely handle this by lookin=
g for the overflow and allowing double max short.

Vikas Goyal <vik=
as@easility.com> wrote:

As there are two ways to support wide rows in CQL3..One is to use composite= keys and another is to use collections like Map, List and Set. The composi= te keys method can have millions of columns (transposed to rows).. This is = solving some of our use cases.

However, if we use collections, I want to know if there is a limit that the= collections can store a certain number/amount of data (Like earlier with T= hrift C* supports up-to 2 billion columns in a row)


Thanks,

Vikas Goyal


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