You don't want to have all the data from a single logger in a single
row b/c of the 2GB size limit.
If you have a small, static number of loggers you could create one CF
per logger and use timestamp as the row key. Otherwise use a
composite key (logger+timestamp) as the key in a single CF.
2010/7/2 Bartosz Kołodziej <bartosz.kolodz...@gmail.com>:
> I'm new to cassandra, and I want use it to store:
> loggers = { // (super)ColumnFamily ?
> logger1 : { // row inside super CF ?
> timestamp1 : {
> value : 10
> },
> timestamp2 : {
> value : 12
> }
> (many many many more)
> }
> logger2 : { //logger of diffrent type (in this example it logs 3 values
> instead of 1)
> timestamp1 : {
> v : 300,
> c : 123,
> s : 12.13
> },
> timestamp2 : {
> v : 300
> c : 123
> s : 12.13
> }
> (many many many more)
> }
> (many many many more)
> }
> the only way i will be accesing this data is:
> - example: fetch slice of data from logger2 ( start = 1278009131 (timestmap)
> , end = 1278109131 )
> expecting sorted array of data.
> - example: fetch slice of data from (logger2 and logger10 and logger20 and
> logger1234) ( start = 1278009131 (timestmap) , end = 1278109131 )
> expecting map of sorted arrays of data. [it is basically N queries of
> first type]
> is this right definition of above: <ColumnFamily CompareWith="TimeUUIDType"
> ColumnType="Super"
> CompareSubcolumnsWith="BytesType" Name="loggers"/> ?
> what's the best way to model this data in cassadra (keeping in mind
> partitioning and other important stuff) ?
>
>
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
