Google Cloud Platform for Developers

Bigtable under the hood

All Bigtable data is stored in a highly distributed, sorted map structure. Data is internally indexed at the column level by combining a row key, a column key, and a timestamp. This index is used as the key that maps to the column's actual value. The inclusion of a timestamp in the index allows Bigtable to store several versions of the same row and column, facilitating concepts such as versioning and garbage collection:

Bigtable data is indexed as row key (com.cnn.www), a column key (contents, anchor:1, anchor:2), and a timestamp (t3,t5,t6); taken from the Google Bigtable white paper, 2006

Because Bigtable stores data ...