The big idea in storing time series data is to partition data by timestamp (daily/hourly/minutely depending on how granular do you want it). This technique can

The big idea in storing time series data is to partition data by timestamp (daily/hourly/minutely depending on how granular do you want it). This technique can be done in various data store: * I've done it in PostgreSQL using triggers and table inheritance. With this technique trimming old data is as simple as dropping old tables. * Logstash folks use daily indices on ElasticSearch to store log data which is time series by nature. * I have heard from quite a few people that Cassandra works really well with this data model too.