Many database vendors provide their own dialect of SQL to supplement the standard. For example, conditional processing, error handling, and flow-of-control statements are often provided by database vendors as an element of their own dialect of the SQL standard.
The ANSI SQL standard SQL/PSM (Persistent Stored Module) package describes many features associated with programming stored procedures and incorporates many of the extensions offered by these dialects. However, the implementation of SQL/PSM is not consistent or reliable across all database vendors.
Some popular dialects of SQL include:
Found in Oracle. PL/SQL stands for Procedural Language/SQL and contains many similarities to the language Ada.
Used by both Microsoft SQL Server and Sybase Adaptive Server. As Microsoft and Sybase have moved away from the common platform they shared early in the 1990s, their implementations of Transact-SQL have also diverged.
The SQL dialect and extensions implemented in PostgreSQL. The acronym stands for Procedural Language/postgreSQL.
The procedural language extensions found in IBM’s DB2 UDB database platform.