Capabilities

Field Manual Section 4 - Operational Limits

Not all tanks are built for every terrain. While Tank provides a unified API, the underlying engines (Postgres, Redis, Mongo, etc.) have vastly different mechanical limits. This matrix details which operations are natively supported, emulated, or impossible on each driver.

Feature Matrix

Feature	Postgres	SQLite	MySQL/MariaDB	DuckDB	MongoDB	ScyllaDB/Cassandra	Valkey/Redis
Transaction	✅	✅	✅	✅	✅	⚠️	⚠️
Join	✅	✅	✅	✅	❌	❌	❌
Bulk Append	✅	❌	❌	✅	❌	❌	❌
Filtering	✅	✅	✅	✅	✅	⚠️	❌
Aggregations	✅	✅	✅	✅	✅	❌	❌

WARNING

• ScyllaDB/Cassandra manages transactions using the batch feature. It can only execute modify statements and it is atomic only within a partition. Moreover the batch accumulates the commands and sends them on commit.

Study the specs. Pick the right armor. Dominate the field.