Types of SQL function in Oracle

Oracle functions may be two types SQL functions and user defined functions. SQL functions are built into oracle database. And user defined functions are created by user.
Based the task performed by oracle functions we can classify oracle functions in the following.

A)Single-Row Functions: Single row functions return just one row for every row of a queried table or view. A detail explanation of single row function is found in

B)Aggregate Functions: Aggregate function returns a single row based on a set of rows. A common use of aggregate function is with the GROUP BY clause in a SELECT statement. A detail explanation of aggregate function is found in

C)Analytic Functions: Analytic functions compute an aggregate value based on a group of rows. The difference of analytic function from aggregate functions in that they return multiple rows for each group. A detail explanation of analytic function is found in

D)Object Reference Functions: Object reference functions manipulate REF values, which are references to objects of specified object types. A detail explanation of object reference function is found in

E)Model Functions: Model functions can be used only in the model_clause of the SELECT statement. A details explanation of model functions are discussed in

F)User Defined Functions:

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