Google Cloud Platform for Developers

Query execution plans

When a query is submitted to Cloud Spanner, it is received by a root node that validates the query, interprets the query into an executable plan, and dispatches the plan to the cluster to be executed. Cloud Spanner attempts to optimize these queries, sometimes resulting in unintuitive execution plans. In order to help understand how queries are interpreted and executed, Cloud Spanner provides insight into the query execution plans.

To see the execution plan for a given query, simply navigate to your desired database in the Google Cloud Console, click QUERY, and execute the query. Once executed, click the Explanation tab to see a graphical breakdown of the steps involved in running your query. The explanation includes ...