Estimating partition size 

Determining how much data your DataStax or Cassandra partitions can hold.

For efficient operation, partitions must be sized within certain limits in DataStax Enterprise and Apache Cassandra™. Two measures of partition size are the number of values in a partition and the partition size on disk. The practical limit of cells per partition is two billion. Sizing the disk space is more complex, and involves the number of rows and the number of columns, primary key columns and static columns in each table. Each application will have different efficiency parameters, but a good rule of thumb is to keep the maximum number of rows below 100,000 items and the disk size under 100 MB.