Password policies in MySQL - Step-by-Step Execution

Concept Flow - Password policies

User sets password

↓

Check password length

Yes↓

Check password complexity

Yes↓

Check password history

Yes↓

Password accepted

No↓

Reject password, show error

When a user sets a password, the system checks length, complexity, and history before accepting or rejecting it.

Execution Sample

MySQL

ALTER USER 'user'@'localhost' PASSWORD EXPIRE;
SET GLOBAL validate_password.length = 8;
SET GLOBAL validate_password.policy = 2;

This code sets password expiration and enforces a strong password policy with minimum length 8.

Execution Table

Step	Action	Password	Check	Result	Next Step
1	User sets password	Pass123!	Length >= 8?	Yes	Check complexity
2	Check complexity	Pass123!	Contains uppercase, lowercase, digit?	Yes	Check history
3	Check history	Pass123!	Not used before?	Yes	Accept password
4	Password accepted	Pass123!	-	-	End
5	User sets password	pass	Length >= 8?	No	Reject password
6	Reject password	pass	-	-	End

💡 Execution stops when password is accepted or rejected based on policy checks.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
Password	None	Pass123!	Pass123!	Pass123!	Pass123!
Length Check	False	True	True	True	True
Complexity Check	False	False	True	True	True
History Check	False	False	False	True	True
Password Accepted	False	False	False	True	True

Key Moments - 2 Insights

Why does the password 'pass' get rejected immediately?

Because in step 5 of the execution_table, the length check fails (password length less than 8), so the password is rejected without further checks.

What happens if the password fails the complexity check?

The execution_table shows that if complexity check fails, the password is rejected before checking history, stopping the process early.

Visual Quiz - 3 Questions

Look at the execution_table, what is the result of the length check for password 'Pass123!' at step 1?

A Not checked

B Yes

C No

D Error

💡 Hint

Refer to row 1, column 'Result' in execution_table.

At which step does the password get accepted?

A Step 4

B Step 3

C Step 5

D Step 6

💡 Hint

Look for the row where 'Password accepted' is the action in execution_table.

If the password fails the complexity check, what is the next step?

A Check history

B Accept password

C Reject password

D Check length again

💡 Hint

Check the flow after complexity check failure in execution_table rows.

Concept Snapshot

Password policies in MySQL:
- Enforce minimum length (e.g., 8 characters)
- Require complexity (uppercase, lowercase, digits)
- Prevent reuse of old passwords
- Use ALTER USER and system variables to set policies
- Passwords failing checks are rejected immediately

Full Transcript

This visual execution shows how MySQL password policies work step-by-step. When a user sets a password, the system first checks if the password length meets the minimum requirement. If it does, it checks the password complexity, ensuring it contains uppercase letters, lowercase letters, and digits. Then it verifies the password is not reused from history. If all checks pass, the password is accepted. If any check fails, the password is rejected immediately. The execution table traces these steps with example passwords. The variable tracker shows how checks update from false to true as the password passes each test. Key moments clarify why short passwords are rejected early and what happens on complexity failure. The quiz tests understanding of these steps. This helps beginners see exactly how password policies enforce security in MySQL.