QuackDB is intentionally protocol-first, but it does not claim full DuckDB Quack protocol coverage yet. This matrix tracks the implemented surface, unsupported gaps, and the test style expected before a feature is treated as covered.
Message coverage
Quack message
Status
Coverage
Connection request
Supported
Codec tests and connection integration
Connection response
Supported
Codec tests and connection integration
Prepare request
Supported
Query, prepare, and stream integration
Prepare response
Supported
Query, prepare, and stream integration
Fetch request
Supported
Streaming/fetch continuation tests
Fetch response
Supported
Streaming/fetch continuation tests
Append request
Supported
Native append integration and quack-ts encode fixtures
Success response
Supported
Append and disconnect paths
Error response
Supported
Query, append, and transport error tests
Disconnect
Supported
DBConnection disconnect cleanup
Vector encoding coverage
Vector encoding
Decode
Encode
Notes
Flat
Supported
Supported
Primary query and append path
Constant
Supported
Not emitted
Decode expands constants to row values
Dictionary
Supported
Not emitted
Decode validates selection indexes
Sequence
Supported
Not emitted
Decode materializes generated values
FSST
Unsupported
Unsupported
Raises explicit :unsupported_vector_type; QuackDB has an internal optional :fsst bridge, but DuckDB currently flattens FSST vectors before Quack serialization and the compressed wire payload shape is not exposed by current DuckDB releases
Unknown vector ids
Unsupported
Unsupported
Raises explicit :unknown_vector_type
Logical type coverage
DuckDB logical type family
Decode
Append encode
Notes
Booleans
Supported
Supported
Signed/unsigned integers
Supported
Supported
Includes hugeint/uhugeint
Floating point
Supported
Supported
Decimal
Supported
Supported
Width-dependent physical storage
VARCHAR/CHAR
Supported
Supported
Invalid UTF-8 raises explicit errors
BLOB
Supported
Supported
Raw bytes
UUID
Supported
Partial
Decode supported; append can encode integer storage but public UUID append ergonomics are not finalized
ENUM
Supported
Partial
Decode supported; append requires encoded enum index today
BIT
Supported
Partial
Decode to bit string; append expects DuckDB bit payload bytes
BIGNUM
Supported
Supported
Elixir integers; fixture covers zero, positive, and negative large values
Decodes to maps; duplicate keys follow Map.put/3 semantics
SQLNULL
Partial
Partial
Covered as ordinary null values, not all standalone logical-type edge cases
UNION
Unsupported
Unsupported
Should raise explicit unsupported errors
VARIANT
Unsupported
Unsupported
Should raise explicit unsupported errors
ANY/TEMPLATE/LAMBDA/POINTER
Unsupported
Unsupported
Protocol metadata reserved/unsupported
AGGREGATE_STATE
Unsupported
Unsupported
Metadata not implemented
Extension/custom types
Unsupported
Unsupported
Metadata not implemented
GEOMETRY
Partial
Partial
Decoded as WKB-compatible bytes from DuckDB spatial geometry values; semantic geometry structs are not implemented
DBConnection and client coverage
Feature
Status
Coverage
Query execution
Supported
Unit and integration
Prepare/execute
Supported
Unit and integration
Streaming/fetch continuation
Supported
Unit and integration
Transactions
Supported
Unit and integration
Native row append
Supported
Unit and integration
Native column append
Supported
Unit and integration
Ecto raw SQL
Supported
Unit and integration
Ecto analytical reads
Partial
Broad SQL-generation and integration coverage
Ecto insert/insert_all
Covered
Plain inserts, returning, insert-from-query, common upserts, on_conflict: :nothing, and explicit native append fast path covered
Ecto mutations and DDL
Partial
Schema update/delete, joined update_all, joined delete_all, rowid-filtered ordered/limited mutations, Repo.explain, transactions, and basic migrator-backed DDL covered where DuckDB SQL allows it
Conformance fixtures
Current cross-implementation fixtures compare QuackDB's append/data chunk encoding byte-for-byte with quack-ts for scalar and nested chunks. See docs/protocol/fixtures.md for the fixture inventory and backlog.