Spanner migration tool is a stand-alone open source tool for Cloud Spanner evaluation and migration, using data from an existing PostgreSQL, MySQL, SQL Server, Oracle or DynamoDB database. The tool ingests schema and data from either a pg_dump/mysqldump file or directly from the source database, and supports both schema and data migration. For schema migration, Spanner migration tool automatically builds a Spanner schema from the schema of the source database. This schema can be customized using the Spanner migration tool schema assistant and a new Spanner database is created using the Spanner schema built.

Installation instructions for Spanner migration tool are available here.

Detailed documentation on how to use spanner-migration-tool is available at: https://googlecloudplatform.github.io/spanner-migration-tool