Comparison of relational database management systems

The following tables compare general and technical information for a number of relational database management systems. Please see the individual products' articles for further information. Unless otherwise specified in footnotes, comparisons are based on the stable versions without any add-ons, extensions or external programs. The operating systems that the RDBMSes can run on. Information about what fundamental RDBMS features are implemented natively. Note (1): Currently only supports read uncommited transaction isolation. Version 1.9 adds serializable isolation and version 2.0 will be fully ACID compliant. Note (2): MariaDB and MySQL provide ACID compliance through the default InnoDB storage engine. Note (3): "For other than InnoDB storage engines, MySQL Server parses and ignores the and syntax in statements. The clause is parsed but ignored by all storage engines." Note (4): Support for Unicode is new in version 10.0. Note (5): MySQL provides GUI interface through MySQL Workbench. Note (6): OpenEdge SQL database engine uses Referential Integrity, OpenEdge ABL Database engine does not and is handled via database triggers. Information about data size limits. Note (1): Firebird 2.x maximum database size is effectively unlimited with the largest known database size >980 GB. Firebird 1.5.x maximum database size: 32 TB. Note (2): Limit is 1038 using DECIMAL datatype. Note (3): InnoDB is limited to 8,000 bytes (excluding VARBINARY, VARCHAR, BLOB, or TEXT columns). Note (4): InnoDB is limited to 1,017 columns. Note (6): Using VARCHAR (MAX) in SQL 2005 and later. Note (7): When using a page size of 32 KB, and when BLOB/CLOB data is stored in the database file. Note (8): Java array size limit of 2,147,483,648 (231) objects per array applies. This limit applies to number of characters in names, rows per table, columns per table, and characters per CHAR/VARCHAR. Note (9): Despite the lack of a date datatype, SQLite does include date and time functions, which work for timestamps between 24 November 4714 B.C. and 1 November 5352.