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 8A6DDD260 for ; Sun, 11 Nov 2012 21:39:15 +0000 (UTC) Received: (qmail 86373 invoked by uid 500); 11 Nov 2012 21:39:12 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 86342 invoked by uid 500); 11 Nov 2012 21:39:12 -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 86334 invoked by uid 99); 11 Nov 2012 21:39:12 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 11 Nov 2012 21:39:12 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: local policy) Received: from [208.113.200.5] (HELO homiemail-a59.g.dreamhost.com) (208.113.200.5) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 11 Nov 2012 21:39:04 +0000 Received: from homiemail-a59.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a59.g.dreamhost.com (Postfix) with ESMTP id 777D756405C for ; Sun, 11 Nov 2012 13:38:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=thelastpickle.com; h=from :content-type:message-id:mime-version:subject:date:references:to :in-reply-to; s=thelastpickle.com; bh=/yZ+BjrFS7+n6UcbkNRxzMWVY0 8=; b=ppHKz/JQkO3ugGzu5t17mKnSXNXLEUu+Aq9DH5petkr+eL+KbKOCEStdXk whucPD4btVu+5CyOY2P4bD/6n1DpY/vcw69VFl6iOqloxxNIKgEUDqLH6CRUqvbN 6K/5N2/B8CnbMa2UTPB0TMD9Wfd4lXM/uunJA6U/Mmtj6No+s= Received: from [192.168.2.13] (unknown [116.90.132.105]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: aaron@thelastpickle.com) by homiemail-a59.g.dreamhost.com (Postfix) with ESMTPSA id 01234564057 for ; Sun, 11 Nov 2012 13:38:47 -0800 (PST) From: aaron morton Content-Type: multipart/alternative; boundary="Apple-Mail=_FEDFA94C-B65F-4C71-AB9B-96607709C099" Message-Id: <7CED871F-DE30-4CDC-9325-48AD8EF9D03C@thelastpickle.com> Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Subject: Re: CREATE COLUMNFAMILY Date: Mon, 12 Nov 2012 10:38:44 +1300 References: <003a01cdbfc8$c134f490$439eddb0$@charter.net> <008201cdc03f$99d4b8a0$cd7e29e0$@charter.net> To: user@cassandra.apache.org In-Reply-To: <008201cdc03f$99d4b8a0$cd7e29e0$@charter.net> X-Mailer: Apple Mail (2.1499) X-Virus-Checked: Checked by ClamAV on apache.org --Apple-Mail=_FEDFA94C-B65F-4C71-AB9B-96607709C099 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Also most idomatic clients use the information so they can return the = appropriate type to you.=20 > Can the metadata be applied > after the fact? If so how? UPDATE COLUMN FAMILY in the CLI will let you change it.=20 Note that we do not update the existing data. This can be a problem if = you do something like change a variable length integer to a fixed length = one.=20 Cheers ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 12/11/2012, at 8:06 AM, Kevin Burton = wrote: > Thank you this helps with my understanding.=20 >=20 > So the goal here is to supply as many name/type pairs as can be = reasonably > be foreseen when the column family is created? Can the metadata be = applied > after the fact? If so how? >=20 > -----Original Message----- > From: Edward Capriolo [mailto:edlinuxguru@gmail.com]=20 > Sent: Sunday, November 11, 2012 9:37 AM > To: user@cassandra.apache.org > Subject: Re: CREATE COLUMNFAMILY >=20 > If you supply metadata cassandra can use it for several things. >=20 > 1) It validates data on insertion > 2) Helps display the information in human readable formats in tools = like the > CLI and sstabletojson > 3) If you add a built-in secondary index the type information is = needed, > strings sort differently then integer > 4) columns in rows are sorted by the column name, strings sort = differently > then integers >=20 > On Sat, Nov 10, 2012 at 11:55 PM, Kevin Burton = > wrote: >> I am sure this has been asked before but what is the purpose of=20 >> entering key/value or more correctly key name/data type values on the=20= >> CREATE COLUMNFAMILY command. >>=20 >>=20 >>=20 >>=20 >=20 --Apple-Mail=_FEDFA94C-B65F-4C71-AB9B-96607709C099 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Also = most idomatic clients use the information so they can return the = appropriate type to you. 

 Can the metadata be applied
after the fact? If so = how?
UPDATE COLUMN FAMILY in the CLI will let you change = it. 
Note that we do not update the existing data. This = can be a problem if you do something like change a variable length = integer to a fixed length = one. 

Cheers

http://www.thelastpickle.com

On 12/11/2012, at 8:06 AM, Kevin Burton <rkevinburton@charter.net> = wrote:

Thank you this helps with my understanding.

So the = goal here is to supply as many name/type pairs as can be = reasonably
be foreseen when the column family is created? Can the = metadata be applied
after the fact? If so how?

-----Original = Message-----
From: Edward Capriolo [mailto:edlinuxguru@gmail.com]
Sent: Sunday, November 11, = 2012 9:37 AM
To: user@cassandra.apache.orgSubject: Re: CREATE COLUMNFAMILY

If you supply metadata = cassandra can use it for several things.

1) It validates data on = insertion
2) Helps display the information in human readable formats = in tools like the
CLI and sstabletojson
3) If you add a built-in = secondary index the type information is needed,
strings sort = differently then integer
4) columns in rows are sorted by the column = name, strings sort differently
then integers

On Sat, Nov 10, = 2012 at 11:55 PM, Kevin Burton <rkevinburton@charter.net><= br>wrote:
I am sure this has been asked = before but what is the purpose of
entering key/value or more = correctly key name/data type values on the
CREATE COLUMNFAMILY = command.






= = --Apple-Mail=_FEDFA94C-B65F-4C71-AB9B-96607709C099--