cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From aaron morton <>
Subject Re: Doubts related to composite type column names/values
Date Tue, 20 Dec 2011 19:44:05 GMT
Component values are compared in a type aware fashion, an Integer is an Integer. Not a 10 character
zero padded string. 

You can also slice on the components. Just like with string concat, but nicer.  . e.g. If
you app is storing comments for a thing, and the column names have the form <comment_id,
field> or  <Integer, String> you can slice for all properties of a comment or all
properties for comments between two comment_id's

Finally, the client library knows what's going on. 

Hope that helps.

Aaron Morton
Freelance Developer

On 21/12/2011, at 7:43 AM, Maxim Potekhin wrote:

> With regards to static, what are major benefits as it compares with
> string catenation (with some convenient separator inserted)?
> Thanks
> Maxim
> On 12/20/2011 1:39 PM, Richard Low wrote:
>> On Tue, Dec 20, 2011 at 5:28 PM, Ertio Lew<>  wrote:
>>> With regard to the composite columns stuff in Cassandra, I have the
>>> following doubts :
>>> 1. What is the storage overhead of the composite type column names/values,
>> The values are the same.  For each dimension, there is 3 bytes overhead.
>>> 2. what exactly is the difference between the DynamicComposite and Static
>>> Composite ?
>> Static composite type has the types of each dimension specified in the
>> column family definition, so all names within that column family have
>> the same type.  Dynamic composite type lets you specify the type for
>> each column, so they can be different.  There is extra storage
>> overhead for this and care must be taken to ensure all column names
>> remain comparable.

View raw message