MonetDB

MonetDB is a full-fledged relational DBMS that supports SQL:2003 and provides standard client interfaces such as ODBC and JDBC. It is designed to exploit the large main memories of modern computers during query processing. A rich collection of linked-in libraries provides functionality for temporal data types, math routine, strings, and URLs. MonetDB is built on the canonical representation of database relations as columns, a.k.a. arrays. They are sizeable entities -up to hundreds of megabytes- swapped into memory by the operating system and compressed on disk upon need. MonetDB excels in applications where the database hot-set - the part actually touched - can be largely held in main-memory or where a few columns of a broad relational table are sufficient to handle individual requests. Further exploitation of cache-conscious algorithms proved the validity of these design decisions. MonetDB is designed to accommodate different query languages through its proprietary algebraic-language, called the MonetDB Assembly Language (MAL). The primary front-end being distributed is a SQL to MAL compiler. MonetDB supports a broad palette of application domains by hooking up external supplied libraries, e.g. pcre, raptor, libxml and geos. Several external file formats are being encapsulated into data vaults, which creates a symbiosis and natural bridge between database processing and legacy file-based processing prevalent in some science domains. For fixed width data types, MonetDB uses a plain C array of the respective type to store the value column of a BAT. MonetDb stores each BAT in a single contiguous file, where columnDB partitions those files in large chunks. MonetDB is used worldwide for education, research, and businesses.