Google Cloud Datastream vs PeerDB

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.

PeerDB streams data from Postgres to data warehouses, queues, and storage engines, using one-way replication. Its supported methods include log-based change data capture, cursor-based replication with timestamps or integers, and XMIN-based replication. A Postgres-compatible SQL interface supports ETL and data movement, and PeerDB handles Postgres data types such as jsonb, arrays, and PostGIS, as well as TOAST columns and schema changes. The actively maintained source connectors are PostgreSQL, MySQL, MongoDB, CockroachDB, and BigQuery; actively maintained destinations are ClickHouse, ClickHouse Cloud, and Postgres. Snowflake, BigQuery, Elasticsearch, Kafka, Redpanda, Confluent, Azure Event Hubs, Google Pub/Sub, and S3 destinations are deprecated and no longer actively maintained. PeerDB is available for free deployment under the AGPL-3.0 license. Paid plans start at $250/mo for Micro, which allows up to two vcores and is recommended for up to 50 million rows moved per month. Larger plans list higher row-volume recommendations and vcore limits. PeerDB states that it is 10x faster than existing tools and reports SOC 2 Type II and GDPR compliance.