.github/workflows | ||
src | ||
.gitignore | ||
LICENSE | ||
pom.xml | ||
README.md |
CavalliumDB Engine
A very simple reactive wrapper for RocksDB and Lucene.
This is not a database, but only a wrapper for Lucene Core and RocksDB, with a bit of abstraction.
Features
-
RocksDB key-value database engine
- Snapshots
- Multi-column database
- Write-ahead log and corruption recovery
- Multiple data types:
- Single value (Singleton)
- Map (Dictionary)
- Composable nested map (Deep dictionary)
- Customizable data serializers
- Values codecs
- Update-on-write value versioning using versioned codecs
-
Apache Lucene Core indexing library
- Snapshots
- 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
F.A.Q.
-
Why is it so difficult to use?
This is not a DBMS.
This is an engine on which a DBMS can be built upon; for this reason it's very difficult to use directly without building another abstraction layer on top.
-
Can I use objects instead of byte arrays?
Yes, you must serialize/deserialize them using a library of your choice.
CodecSerializer allows you to implement versioned data using a codec for each data version. Note that it uses 1 to 4 bytes more for each value to store the version.
-
Why there is a snapshot function for each database part?
Since RocksDB and lucene indices are different software, you can't take a snapshot of everything in the same instant.
A single snapshot must be implemented as a collection of all the snapshots.
-
Is CavalliumDB Engine suitable for your project?
No.
This engine is largely undocumented, and it doesn't provide extensive tests.
Examples
In src/example/java
you can find some quick implementations of each core feature.