5

I have a requirement where i need my database to store the following data:

- For each build, store the results of 3 performance runs. The result includes tps and latency.

Reading up on cassandra data model, this directly maps to a super column family of the following format:

BenchmarkSuperColumnFamily= {

build_1: {
   Run1: {1000K, 0.5ms}
   Run2: {1000K, 0.5ms}
   Run3: {1000K, 0.5ms}
}

build_2: {
   Run1: {1000K, 0.5ms}
   Run2: {1000K, 0.5ms}
   Run3: {1000K, 0.5ms}
}
...

}

But, i read in the following answer that the use of Super Column family is discouraged. I wanted to know if there is a better way of creating a model for my requirement.

PS, I borrowed the JSONish notation from the following article

Community
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Chander Shivdasani
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1 Answers1

6

The StackOverflow answer that you linked to is correct. You shouldn't be using SuperColumns in new applications. They exist for backwards compatibility however.

In general, composite columns can be used to mimic any model provided by super columns. Basically, they allow you to separate your column names into multiple parts. So if you were to specify a comparator of 'CompositeType(UTF8Type, UTF8Type)', your data model wound end up looking like this:

BenchmarkColumnFamily= {

   build_1: {
       (Run1, TPS) : 1000K
       (Run1, Latency) : 0.5ms
       (Run2, TPS) : 1000K
       (Run2, Latency) : 0.5ms
       (Run3, TPS) : 1000K
       (Run3, Latency) : 0.5ms
    }

    build_2: {
       ...
    }
...

}

With the above model you could use a single query to get a single data point for a single run, all data points for a single run, or all data points for multiple runs.

More info on composite columns: http://www.datastax.com/dev/blog/introduction-to-composite-columns-part-1

danb
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nickmbailey
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  • is there a way to create such columns through cassandra-cli? – Chander Shivdasani Jun 26 '12 at 19:21
  • Unfortunately no. You can do it through the api using one of the many client libraries. Also you could do it using the newer CQL interface and the cqlsh command line tool. CQLv3 will actually abstract the fact that you are using composite columns at all. Also CQLv3 is still beta. More info: http://www.datastax.com/dev/blog/whats-new-in-cql-3-0 – nickmbailey Jun 27 '12 at 14:55