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From aaron morton <aa...@thelastpickle.com>
Subject Re: CREATE COLUMNFAMILY
Date Sun, 11 Nov 2012 21:38:44 GMT
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

-----------------
Aaron Morton
Freelance Developer
@aaronmorton
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.org
> Subject: 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>
> 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.
>> 
>> 
>> 
>> 
> 


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