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 Extend operators and built-in functions.