incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Chris Gerken <chrisger...@mindspring.com>
Subject Re: yet a couple more questions on composite columns
Date Sat, 04 Feb 2012 03:27:58 GMT

> 
> 
> On 4 February 2012 06:21, Yiming Sun <yiming.sun@gmail.com> wrote:
> I cannot have one composite column name with 3 components while another with 4 components?
>  Just put 4 components and left last empty (if it is same type)?!
> 
> Another question I have is how flexible composite columns actually are.  If my data model
has a CF containing US zip codes with the following composite columns:
> 
> {OH:Spring Field} : 45503
> {OH:Columbus} : 43085
> {FL:Spring Field} : 32401
> {FL:Key West}  : 33040
> 
> I know I can ask cassandra to "give me the zip codes of all cities in OH".  But can I
ask it to "give me the zip codes of all cities named Spring Field" using this model?  Thanks.
> No. You set first composite component at first.

I'd use a dynamic CF:
row key = state abbreviation 
column name = city name
column value = zip code (or a complex object, one of whose properties is zip code)

you can iterate over the columns in a single row to get a state's city names and their zip
code and you can do a get_range_slices on all keys for the columns starting and ending on
the city name to find out the zip codes for a cities with the given name.

I think

- Chris
Mime
View raw message