incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Maxim Potekhin <potek...@bnl.gov>
Subject Re: Doubts related to composite type column names/values
Date Tue, 20 Dec 2011 20:33:25 GMT
Thank you Aaron! As long as I have plain strings, would you say that I 
would do almost as well with catenation?

Of course I realize that mixed types are a very different case where the 
composite is very useful.

Thanks

Maxim


On 12/20/2011 2:44 PM, aaron morton wrote:
> 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
> @aaronmorton
> http://www.thelastpickle.com
>
> 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<ertiop93@gmail.com 
>>> <mailto:ertiop93@gmail.com>>  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.
>>>
>>
>


Mime
View raw message