System lock
The thread is going to request or is waiting for an internal or external system lock for the table.
Detailed Description​
The thread is going to request or is waiting for an internal or external system lock for the table. If this state is being caused by requests for external locks and you are not using multiple mysqld servers that are accessing the same MyISAM tables, you can disable external system locks with the --skip-external-locking option. However, external locking is disabled by default, so it is likely that this option will have no effect. For SHOW PROFILE, this state means the thread is requesting the lock (not waiting for it).
How to reduce this wait​
Not available yet. Contributions welcome.
Additional Links​
MySQL Docs - General Thread States
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