The **GREATEST** is an inbuilt function in PLSQL which is used to return the greatest value from a given list of some expressions. These expressions may be numbers, alphabets etc.

**Syntax:**

GREATEST(exp1, exp2, ... exp_n)

**Parameters Used:**

This function accept some parameters like **exp1, exp2, … exp_n**. These each expression may be numbers or alphabets on which GREATEST() function is called.

**Return Value:**

This function returns the greatest value from a given list of expressions.

**Supported Versions of Oracle/PLSQL is given below:**

- Oracle 12c
- Oracle 11g
- Oracle 10g
- Oracle 9i
- Oracle 8i

Let’s see some examples which illustrate the GREATEST function:

**Example-1:**

DECLARE Test_Number number1 := 1; Test_Number number2 := 2; Test_Number number3 := 5; Test_Number number4 := 30; BEGIN dbms_output.put_line(GREATEST(Test_Number number1, Test_Number number2, Test_Number number3, Test_Number number4)); END;

**Output:**

30

In the above example, some list of numbers is taken as the parameter out of which greatest number is returned as the output. for example, 1, 2, 5 and 30 is taken as the parameter out of which 30 is returned because it is the greatest number.

**Example-2:**

DECLARE Test_Number number1 := 'a'; Test_Number number2 := 'b'; Test_Number number3 := 'c'; BEGIN dbms_output.put_line(GREATEST(Test_Number number1, Test_Number number2, Test_Number number3)); END;

**Output:**

c

In the above example, some list of alphabets is taken as the parameter out of which greatest in count alphabet is returned as the output. for example, a, b and c is taken as the parameter out of which c is returned because it is the greatest in the count.

**Example-3:**

DECLARE Test_Number number1 := 0; Test_Number number2 := -4; Test_Number number3 := 0.6; BEGIN dbms_output.put_line(GREATEST(Test_Number number1, Test_Number number2, Test_Number number3)); END;

**Output:**

0.6

In the above example, some list of numbers is taken as the parameter out of which greatest number is returned as the output. for example, 0, -4 and 0.6 is taken as the parameter out of which 0.6 is returned because it is the greatest number.

**Advantage:**

This function is used to find the greatest expression out of the given input expressions. This expression might be any numbers or alphabets.