MariaDB BENCHMARK() Function

In MariaDB, BENCHMARK() is a built-in function that executes a given expression a specified number of times.

The MariaDB BENCHMARK() function is primarily used in the command line tool to report query execution times.

MariaDB `BENCHMARK()` Syntax

Here is the syntax of the MariaDB BENCHMARK() function:

BENCHMARK(count, expr)

Parameters

count: Optional. specified number of times.
expr: Optional. The expression to execute.

If you do not provide the wrong number of arguments, MariaDB will report an error: ERROR 1582 (42000): Incorrect parameter count in the call to native function 'BENCHMARK'.

Return value

The MariaDB BENCHMARK() function alwayss return 0.

If the first parameter is given a negative count or NULL, the BENCHMARK() function will return NULL.

MariaDB `BENCHMARK()` Examples

Example 1

The following example shows how to use the BENCHMARK() function execute the MD5('aaa') function 10000000 times.

SELECT BENCHMARK(10000000, MD5('aaa'));

+---------------------------------+
| BENCHMARK(10000000, MD5('aaa')) |
+---------------------------------+
|                               0 |
+---------------------------------+
1 row in set (1.502 sec)

The function returns 0, but you can get the execution time from the output: 1 row in set (1.502 sec).

Example 2

The following example shows how to use the BENCHMARK() function execute the SLEEP(1) function 10 times.

SELECT BENCHMARK(10, SLEEP(1));

Output:

+-------------------------+
| BENCHMARK(10, SLEEP(1)) |
+-------------------------+
|                       0 |
+-------------------------+
1 row in set (10.111 sec)

In this example, the SLEEP(1) function will execute temporarily for 1 second.

Example 3 - Negative or `NULL`

If the first parameter is given a negative count or NULL, the BENCHMARK() function will return NULL.

SELECT
  BENCHMARK(-10, SLEEP(1)),
  BENCHMARK(NULL, SLEEP(1));

Output:

+--------------------------+---------------------------+
| BENCHMARK(-10, SLEEP(1)) | BENCHMARK(NULL, SLEEP(1)) |
+--------------------------+---------------------------+
|                     NULL |                      NULL |
+--------------------------+---------------------------+
1 row in set, 1 warning (0.000 sec)

Conclusion

In MariaDB, BENCHMARK() is a built-in function that executes a given expression a specified number of times.

MariaDB BENCHMARK() Syntax