OrioleDB PostgreSQL Storage Engine

OrioleDB is a free and open-source storage engine for PostgreSQL that combines the reliability of traditional database storage with the performance of modern cloud-native architectures. Created by Oriole DB Inc. (founded in 2021) and led by Alexander Korotkov, OrioleDB is designed as a drop-in replacement for PostgreSQL's default heap-table storage engine, addressing its limitations in write amplification, bloat, and undo log management. Key features: undo log architecture: instead of PostgreSQL's traditional multiversion concurrency control (MVCC) via dead tuples, OrioleDB uses an undo log to keep old row versions, significantly reducing table bloat and the need for vacuuming. This approach is similar to Oracle Database and MySQL InnoDB. Page merging: automatic merging of partially filled pages, eliminating the need for page-level vacuum operations. Copy-on-write B-trees: all index updates are copy-on-write, with undo log entries for old versions, ensuring consistency without full-page writes (which reduces WAL traffic). Compression: built-in transparent compression at the page level, reducing storage footprint and I/O bandwidth. Shared storage support: designed to work with shared block storage (NFS, cloud block storage) enabling compute-storage separation. Checksums: page-level checksums for data integrity. Separate tablespaces: OrioleDB tables can coexist with standard PostgreSQL tables in the same database. Transactional DDL: schema changes are fully transactional with minimal locking. Point-in-time recovery via undo logs. The storage engine passes PostgreSQL's standard regression test suite. Extension-based: installed as a PostgreSQL extension (CREATE EXTENSION orioledb) without modifying core PostgreSQL. Compatible with PostgreSQL 13+. PostgreSQL License.