Distributed SQL database in Rust, written as a learning project.

• Networking: gRPC, no security.

• Storage: Self-written key-value engine using LSM-trees and/or B+-trees, with secondary indexes. MessagePack for serialization. No log compaction or write-ahead log.

• Consensus: Self-written Raft implementation, handling all writes and reads. Node time is (naively) considered accurate.

• Data Types: Support for nulls, booleans, signed 64-bit doubles, and short UTF-8 strings.

• Constraints: Singular required primary keys, unique indexes, and foreign keys.

• Transactions: MVCC-based serializable snapshot isolation.

• Query Engine: Simple heuristic-based planner and optimizer supporting expressions, functions, and inner joins.

• Language: Basic SQL support

  • [CREATE|DROP] TABLE ... and [CREATE|DROP] INDEX ...
  • BEGIN, COMMIT, and ROLLBACK
  • INSERT INTO [TABLE] (...) VALUES (...)
  • UPDATE [TABLE] SET ... WHERE ...
  • DELETE FROM [TABLE] WHERE ...
  • SELECT ... FROM ... WHERE ... ORDER BY ...
  • EXPLAIN SELECT ...

• Client: Simple interactive REPL client over gRPC.