TokuDB is a highly scalable, zero maintenance downtime, MySQL storage engine that delivers indexing-based query acceleration and enables hot schema modifications designed for high performance on write-intensive workloads.

TokuDB is a plugin storage engine requiring no changes to MySQL applications or code and is fully ACID (Atomicity, Consistency, Isolation, and Durability) and MVCC (Multi-version Concurrency Control) compliant.
Once you install TokuDB, you can define any table to use TokuDB, MyISAM, InnoDB, or any other storage engine.

Features of TokuDB:

• Hot schema changes:
  • Hotindex creation: TokuDB tables support insertions, deletions and queries with no down time while indexes are being added to that table. It uses Fractal Tree for indexing while innodb uses B-Tree
  • Hot column addition and deletion: TokuDB tables support insertions, deletions and queries with minimal down time when an alter table adds or deletes columns.
• Fast recovery time (seconds, not hours or days).
• Immunity to database disorder or "aging" and the gradual performance degradation it causes.
• 5x-15x data compression. TokuDB typically achieves a 5x-15x space savings on data and indexes over InnoDB due to aggressive compression. TokuDB 5.2.7 does not compress logs.
• Fragmentation Immunity: no dump/reload downtime and no index fragmentation.

System requirements:

• TokuDB supports 64 bit operating systems only
• TokuDB requires at least 1GB of main memory.
• Does't Support Mysql 5.5 till now, hopefully it will within a few months.

Installation of TokuDB over mysql 5.1

1. Register at Tokutek Registration page
2. Download the version that supports your version from TokuDB Download Page (free for evaluation purposes or in production up to 50GB of user data). and extract it in /tmp
3. Take a backup of your databases.
4. Stop mysql
   $ service mysql stop
5. $ mv /tmp/mysql-5.1.52-tokudb-5.2.7-38674-linux-x86_64 /usr/local/mysql
6. $ cd /usr/local/mysql
7. $ bin/mysql_install_db --user=mysql --basedir=$PWD
8. $ bin/mysqld_safe --basedir=$PWD &

mysql> show engines\G
*************************** 5. row ***************************
      Engine: TokuDB
     Support: YES
     Comment: Tokutek TokuDB Storage Engine with Fractal Tree(tm) Technology
Transactions: YES
          XA: NO
  Savepoints: YES