Debezium vs Google Cloud Datastream

Debezium captures row-level database changes and delivers them to applications as events, so they can respond to inserts, updates, and deletes. Its connectors use database logs for low-delay capture without requiring changes to the data model, and can take initial or incremental snapshots, filter schemas, tables, and columns, and mask selected values. Listed databases include MongoDB, MariaDB, MySQL, PostgreSQL, SQL Server, Oracle, Db2, and Cassandra. Connectors for Vitess, Spanner, Informix, CockroachDB, YashanDB, Ingres, and Milvus are marked incubating and may change without backward compatibility. A common deployment uses Apache Kafka Connect; Debezium can also run through Debezium Server or as a library in JVM applications. Debezium Server can send serialized events to Amazon Kinesis, Google Cloud Pub/Sub, and Apache Pulsar. Ready-to-use transformations support routing, filtering, and event flattening. Debezium is free under the Apache Software License 2.0. Its quay.io container images are for testing and evaluation, not production.

Google Cloud Datastream is a serverless change data capture and replication service for synchronizing data. Streams can capture ongoing updates and backfill historical records, while the service scales automatically without resources for users to provision or manage. Supported destinations include BigQuery, Cloud Storage, and Apache Iceberg tables. Documented sources include Oracle, MySQL, PostgreSQL, AlloyDB, SQL Server, MongoDB, Spanner, Salesforce, ServiceNow, Workday, and Microsoft Dataverse; some sources are marked as preview. Datastream can work with Dataflow templates to load data from Cloud Storage into destinations including BigQuery, Cloud SQL, and Spanner. Connectivity options include IP allowlisting, a forward SSH tunnel, and private connectivity over VPC peering. Processing is charged, idle streams incur no cost, and other Google Cloud resources are billed separately. The free tier includes 100 GiB of eligible CDC data per month per billing account. Events are delivered at least once, but ordering is not guaranteed. Datastream is administered through the Google Cloud console, CLI, or REST API.