Compression

Bit Packing / Mostly Encoding Prefix Compression

InfinityDB supports compression for both in-memory and on disk data. It uses ZLib for compressing common substrings and small values via Huffman coding. Furthermore, it also supports prefix and suffix compression to remove common-prefixes in keys and common suffixes in upper tree levels. Other compression methods, including variable-length concatenations of primitives and variable-length encoded Java primitives, are used as well.

Concurrency Control

Optimistic Concurrency Control (OCC)

InfinityDB 1.0 only executes one global transaction at a time. Any data store modification in the system will be visible to all threads. No lock is used and one global transaction is effected all the time.

InfinityDB 2.0 added support for multi-threaded transactions using optimistic concurrency control. If one transaction of a particular thread has held one lock and another transaction of another thread requests this lock. The existing locks of the requester are all released, the transaction is reset to the not-in-progress state and changes are rolled back. InfinityDB does not use pessimistic locking to avoid deadlocks.

Data Model

Relational Key/Value Graph Hierarchical Array / Matrix

InfinityDB supports a rich data representation space. ItemSpace is the lowest-level data model containing a set of Items. The basic data model can be used to define huge spare arrays, matrix, any mixture of trees, graphs, key/value maps, key/value maps or user-defined structures.

Indexes

B+Tree

InfinityDB is based on its own proprietary lock-free, concurrent B+tree.

Isolation Levels

Read Committed Serializable

InfinityDB 1.0 transactionality provides no isolation. For InfinityDB 2.0, it supports Serializable and Read Committed transaction isolation modes.

Logging

Shadow Paging

InfinityDB uses a copy-on-write approach for updating the database, thus it does not require a log.

Storage Architecture

Hybrid

InfinityDB stores and compresses data on disk and in memory.

System Architecture

Embedded

InfinityDB is an embedded database engine written in Java.