Core Concepts

HTAP — Hybrid Transactional/Analytical Processing

ParticleDB is an HTAP database. It runs OLTP transactions (INSERT, UPDATE, DELETE with full ACID guarantees) and OLAP analytics (complex GROUP BY, aggregations over billions of rows) on the same data, in the same engine.

Traditional architectures require separate databases for transactions (PostgreSQL, MySQL) and analytics (ClickHouse, BigQuery) connected by ETL pipelines. ParticleDB eliminates this split:

Traditional Stack	ParticleDB
PostgreSQL (OLTP) + ClickHouse (OLAP) + Pinecone (vectors) + Redis (cache)	One database
ETL pipeline with hours of lag	Real-time analytics on live data
4 connection strings, 4 schemas	1 connection string

Transaction Modes

ParticleDB picks the concurrency model at server start via --txn-mode:

Mode	Behavior	When to use
`fast`	No locks; commit-on-write	Bulk loads, single-writer benchmarks
`occ-v3`	Overlay + commit-time OCC write-set validation (default)	General OLTP — safe under concurrency
`serializable-ssi`	Adaptive serializable snapshot isolation (PL-3); alias `ssi`	Serializable workloads with optimistic concurrency
`strict-serializable`	Serializable-SSI plus real-time ordering; alias `strict-ser`	Strongest guarantee
`table-2pl`	Exclusive table locks at first touch; alias `2pl`	Strict serialization via locking, simple semantics

If you do not pass --txn-mode, the server picks occ-v3, except when --wal-sync-mode sync is set (then table-2pl).

The names occ, occ-v2, zero-copy-occ, zcocc, serializable-occ, and row-2pl are accepted as deprecated aliases for occ-v3.

Wire Protocol Compatibility

ParticleDB speaks the PostgreSQL v3 wire protocol natively. Any tool, driver, or ORM that works with PostgreSQL works with ParticleDB:

psql, pgAdmin, DBeaver
JDBC, Npgsql, psycopg2, node-postgres, sqlx
Diesel, SQLAlchemy, Prisma, GORM

No custom drivers required. Connect to port 5432 and run SQL.