MySQL: To see database parameters

 In MySQL, you can view system parameters (also called system variables) using the SHOW VARIABLES statement or by querying the performance_schema tables.

Here are the main ways:

1. Show all system parameters

Sql
SHOW VARIABLES;

This lists every system variable and its current value for your session.

2. Show specific parameters by name pattern

Sql
SHOW VARIABLES LIKE 'max_connections';
SHOW VARIABLES LIKE 'innodb%';

• % is a wildcard for matching multiple variables.

3. Show global vs session values

Sql
-- Global values (affect all connections)
SHOW GLOBAL VARIABLES;

-- Session values (specific to your current connection)
SHOW SESSION VARIABLES;

4. Using performance_schema

Sql
SELECT * 
FROM performance_schema.global_variables
WHERE VARIABLE_NAME LIKE 'max_connections';

This is useful for more complex filtering or joining with other metadata.

✅ Tip:
If you want to see both the current session and global values for a variable:

Sql
SHOW GLOBAL VARIABLES LIKE 'sql_mode';
SHOW SESSION VARIABLES LIKE 'sql_mode';