Kyoto Cabinet

Kyoto Cabinet is a library of routines for managing a database. 

It's a key/value sql store. Every key and value is serial bytes with variable length. Both binary data and character string can be used as a key and a value. Each key must be unique within a database. 

• There is neither concept of data tables nor data types. Records are organized in hash table or B+ tree.
• Kyoto Cabinet runs very fast

          For example, elapsed time to store one million records is 0.9 seconds for hash database, and 1.1 seconds for B+ tree database.

• Moreover, the size of database of Kyoto Cabinet is very small. 

          For example, overhead for a record is 16 bytes for hash database, and 4 bytes for B+ tree database. Furthermore, scalability of Kyoto Cabinet is great. The database size can be up to 8EB (9.22e18 bytes).

• Kyoto Cabinet is written in the C++ language, and provided as API of C++, C, Java, Python, Ruby, and Perl. 
• Kyoto Cabinet is a free software licensed under the GNU General Public License.