Google Cloud Platform for Developers

Column families

Bigtable rows can potentially be very large, and storing and retrieving the entire contents of very large rows is an expensive operation. To help with this, Bigtable supports the concept of column families. Column families are defined at the table level and allow for subsets of columns to be read without loading the entire row.

Generally, it's best to group columns into families based on access patterns, so that when retrieving columns in order to perform some action, only the columns needed to perform that action are retrieved. It is recommended to use column families wherever possible, though column families should be limited to about 100 families per table.