Delta

DDD-centric event-sourcing library for the JVM.

What's in a name?

symbol symbol: δ; symbol: Δ; symbol: delta 1. MATHEMATICS variation of a variable or function. 2. MATHEMATICS a finite increment.

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Delta encoding is a way of storing or transmitting data in the form of differences (deltas) between sequential data

Non-blocking code, Future based API.
Pluggable architecture. Storage and messaging are implementation neutral. With multiple supported implementations, it's easier to use with existing infrastructure. Current implementations:
- Storage:
  - Generic JDBC, with MySQL, and PostgreSQL adaptations. Custom adaptions are straightforward.
  - MongoDB
  - Cassandra
- Messaging:
  - Redis Pub/Sub
  - Hazelcast Topic
No third-party dependencies (except for storage/messaging implementations)
Minimally invasive. Large degree of freedom in implementation. Uses type classes instead of inheritance. No annotation hell.
Fast, scalable. Written for very large data sets; supports both horizontal and vertical scaling.
Customizable. Attempts to provide sane defaults, but enables high degree of customization.

Complete data history. Intrinsically complete and correct audit trail of any and all changes.
Very fast. Append-only writes. Prebuilt reads (push and pull).
Scalable; effortless sharding.
No object-relational mismatch.
No RDBMS schema upgrades.
Fully separate OLTP/OLAP.
Easy and flexible authentication. Any and all updates are done through explicit, use case specific, commands, each of which can have custom authentication, if required.