Welcome to the home page of HeliDB – a simple and fast Java database!
HeliDB is a database for persisting key—value pairs from a Java program.
Users have many choices in configuring what capabilities they want the database
to have and in how the data is stored. In its simplest configuration, HeliDB is
just a file-backed
Map. More advanced configurations support
transactions and fast searches and inserts through using B+ Trees.
Notable features are:
- The HeliDB
Databaseinterface extends Java's
Map, so a HeliDB database can be used as a drop-in replacement for a
Databaseinterface defines methods that are more efficient for working with persistent data than the methods from
- A database can be configured to support transactions.
- Database operations can be made faster by indexing data in B+ Trees.
- Database object creation is fast, so clients can create new databases as necessary without having to worry about performance.
- The database runs in the same process as the Java program which makes database calls just local function calls. (i.e. fast)
When should I use HeliDB?
HeliDB is a great choice when you want to persist key—value pairs, but don't want to use a full-blown SQL database.
What limitations does HeliDB have?
- Data is stored as key—value pairs. There is no way of searching for data within values (like selecting for data in table columns in an SQL database).
- Transactions don't allow concurrent writes to the same database.
- 09/21/2009: HeliDB 1.1.1 released
- Version 1.1.1 comes with performance improvements for the BPlusTree and the ConstantSizeStringSerializer. See the release notes and the change log for details.
- 07/26/2009: HeliDB 1.1 released
- This release adds support for searching for closest key matches. The new Cursor can be used to navigate through the records in a database. See the release notes and the change log for details.
- 07/15/2009: HeliDB 1.0.2 released
- This version updates the EntityFS dependency to version 1.1.3. See the release notes and the change log for details.
- 02/06/2009: HeliDB 1.0.1 released
- This version upgrades the EntityFS dependency to version 1.1. See the release notes and the change log for details.
- 08/27/2008: HeliDB 1.0 released
- The initial version of HeliDB was released.