1. Check the error log for the MySQL 1691 error:
$ tail -f /var/log/mysql/error.log
2. Check the MySQL configuration file for any misconfigurations:
$ cat /etc/mysql/my.cnf
3. Check the MySQL user privileges:
$ mysql -u root -p
mysql> SELECT User, Host, Password FROM mysql.user;
4. Check the MySQL database tables:
$ mysql -u root -p
mysql> SHOW TABLES;
5. Check the MySQL database table structure:
$ mysql -u root -p
mysql> DESCRIBE table_name;
6. Check the MySQL database table indexes:
$ mysql -u root -p
mysql> SHOW INDEX FROM table_name;
7. Check the MySQL database table constraints:
$ mysql -u root -p
mysql> SHOW CREATE TABLE table_name;
8. Check the MySQL database table triggers:
$ mysql -u root -p
mysql> SHOW TRIGGERS;
9. Check the MySQL database table views:
$ mysql -u root -p
mysql> SHOW CREATE VIEW view_name;
10. Check the MySQL database table stored procedures:
$ mysql -u root -p
mysql> SHOW CREATE PROCEDURE procedure_name;
11. Check the MySQL database table functions:
$ mysql -u root -p
mysql> SHOW CREATE FUNCTION function_name;
12. Check the MySQL database table events:
$ mysql -u root -p
mysql> SHOW EVENTS;
13. Check the MySQL database table locks:
$ mysql -u root -p
mysql> SHOW OPEN TABLES;
14. Check the MySQL database table privileges:
$ mysql -u root -p
mysql> SHOW GRANTS FOR user_name;
15. Check the MySQL database table replication:
$ mysql -u root -p
mysql> SHOW SLAVE STATUS;
16. Check the MySQL database table performance:
$ mysql -u root -p
mysql> SHOW GLOBAL STATUS;
17. Use an automated database observability tool to monitor and fix the MySQL 1691 in question. Automated database observability tools can provide real-time insights into the performance and health of your database, allowing you to quickly identify and fix any issues that may arise. These tools can also provide detailed metrics and logs that can be used to troubleshoot and diagnose any issues that may arise.