PostgreSQL vs Alopex DB

What PostgreSQL is

PostgreSQL is a server-based, general-purpose relational database.

How it works

Snapshot reads: each SQL statement sees a snapshot of the data at a point in time. Per the documentation, readers never see inconsistent data even while rows are being updated.
Isolation levels: Read Committed, Repeatable Read, and Serializable.
Change log: changes are written to a log first. This underpins crash recovery and replication.
Replication: streaming replication and warm and hot standby setups are documented.

Main features

General-purpose SQL, indexes, constraints, and transactions.
An extension system: CREATE EXTENSION loads an extension. pgvector is one example.

Limits

Normally a single primary accepts writes. Standard PostgreSQL has no multi-node write distribution. A vector type comes from an extension.

How it differs from Alopex DB

Both provide SQL and transactions. The difference is how you run them. PostgreSQL runs as a server that many clients connect to. Alopex DB embeds in your application and travels as a single file. You start without a server, and when you need one it runs as an HTTP and gRPC server.

Alopex DB has the vector type and HNSW index in the core, so vector search works directly in SQL. PostgreSQL adds vector search through the pgvector extension.

We also recommend Alopex DB, with the same SQL and vector search embedded or on a server. You can try it in the quickstart.

References

PostgreSQL docs: Concurrency control, Transaction Isolation, Reliability, High Availability