CavalliumDB Engine

A very simple wrapper for RocksDB and Lucene, with gRPC and direct connections.

This is not a database, but only a wrapper for Lucene Core and RocksDB, with a bit of abstraction.

Features

RocksDB Key-Value NoSQL database engine

• Snapshots
• Multi-column databases
• WAL and corruption recovery strategies
• Multiple data types:
  • Bytes (Singleton)
  • Maps of bytes (Dictionary)
  • Maps of maps of bytes (Deep dictionary)
  • Sets of bytes (Dictionary without values)
  • Maps of sets of bytes (Deep dictionary without values)

Apache Lucene Core indexing library

• Documents structure
• Sorting
  • Ascending and descending
  • Numeric or non-numeric
• Searching
  • Nested search terms
  • Combined search terms
  • Fuzzy text search
  • Coordinates, integers, longs, strings, text
• Indicization and analysis
  • N-gram
  • Edge N-gram
  • English words
  • Stemming
  • Stopwords removal
• Results filtering
• Snapshots

F.A.Q.

Why is it so difficult?

This is not a DMBS.

This is an engine on which a DBMS can be built upon. For this reason it's very difficult to use it directly without using it through abstraction layers.

Can I use objects in the database?

Yes you must serialize/deserialize them using a library of your choice.

Why there is a snapshot function for each database part?

Since RocksDB and lucene indices are different instances, every instance has its own snapshot function.

To have a single snapshot you must implement it as a collection of sub-snapshots in your DBMS.

Is CavalliumDB Engine suitable for your project?

No. This engine is largely undocumented, and it doesn't provide extensive tests on its methods.