Destinations

Supabase ETL ships official destination implementations in the etl-destinations crate. Enable only the destination feature you need when embedding ETL or building the standalone replicator. BigQuery is the stable, recommended default.

Status definitions

• Stable: The most mature built-in destination and the recommended default. Review its limitations and validate it against your production workload.
• In progress: Functional, but behavior, configuration, schema support, and operational requirements may still change. Test recovery and schema changes before production use.
• Deprecated: Retained for compatibility but no longer recommended for new deployments. Plan to move away from it.

BigQuery

Stable

BigQuery uses the BigQuery Storage Write API and BigQuery change data capture to maintain destination tables. The standalone replicator guide uses BigQuery as its default example.

Limitations

• Every replicated source table needs a primary key, and all primary-key columns must be included in the publication.
• PostgreSQL arrays containing NULL elements are not supported.
• Supported schema changes are applied automatically, but PostgreSQL default expressions and backfill behavior are only supported where they map safely to BigQuery. See Schema Changes.

ClickHouse

In progress

ClickHouse supports a current-state layout with ReplacingMergeTree and an append-only event-log layout with MergeTree.

Limitations

• The default ReplacingMergeTree layout requires a source primary key with every primary-key column included in the publication, and requires ClickHouse 23.5 or newer.
• MergeTree preserves an append-only event log; it does not expose a current-state replica by itself.
• Tombstone cleanup and OPTIMIZE ... FINAL CLEANUP are operator-managed.

DuckLake

In progress

DuckLake writes through DuckDB to a file or PostgreSQL catalog and local or object storage.

Limitations

• Data storage URLs currently support file, s3, and gs schemes.
• Deployments must account for the required DuckDB extensions and the catalog, storage, and maintenance services they configure.
• Primary-key sorting requires source tables to have a primary key; other sorting modes do not add that requirement.

Snowflake

In progress

Snowflake uses direct Snowpipe Streaming and key-pair authentication.

Limitations

• Setup requires a Snowflake user and role with the documented warehouse, database, and schema privileges.
• Schema evolution support is still in progress. Only defaults that ETL can translate safely are applied; unsupported expressions are skipped with a warning.
• Validate channel recovery, committed offsets, and account-specific resource limits before production use.

Iceberg

Deprecated

The Apache Iceberg implementation is retained for compatibility and is not recommended for new deployments.

Limitations

• Schema-change DDL is not supported. A newer relation schema is rejected.
• The destination is deprecated and is not receiving the same product investment as the active destination implementations.

Custom destinations and upstream support

Adding an official destination is a long-term maintenance commitment. It requires durable and idempotent writes, schema-evolution behavior, restart and recovery coverage, integration infrastructure, credential handling, ongoing dependency updates, and operational support. For that reason, maintainers are careful about accepting new destination implementations upstream. Open an issue or discussion before investing in an upstream implementation; acceptance is not guaranteed.

You do not need to contribute a destination upstream to use ETL. Implement the Destination trait in your own Rust project, wire it into Pipeline::new, and maintain it alongside your application. See Custom Implementations for a complete example.