Operations

A data type tells the database server which operations it can perform on the data type values. The database server provides the following types of operations on data types:

• An operator function implements a particular operator symbol.

  The plus() and times() functions are examples of operator functions for the + and * operators, respectively.

• A built-in function is a predefined function that the database server provides for use in SQL statements.

  The cos() and hex() functions are examples of built-in functions.

• An aggregate function returns a single value for a set of retrieved rows.

  The SUM and AVG functions are examples of aggregate functions.

• An end-user routine is a UDR that end users can use in SQL statements to perform some useful action.

The database server provides operator functions, built-in functions, and aggregate functions that handle the data types that it provides. For a description of these operations and how to extend them, see Extending Operators and Built-In Functions.