MySQL check whether the table is locked

mysql Look at the locked table 
 
 Check whether the table is locked 
show OPEN TABLES where In_use > 0;
 View all processes 
MySQL:
 
show processlist;
mariabd:
 
show full processlist;
 Query the corresponding process === then  kill id
 
 Kill the designated mysql The process number of the connection 
kill $pid
 View the transaction being locked 
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCKS; 
 View transactions waiting for locks 
SELECT * FROM INFORMATION_SCHEMA.INNODB_LOCK_WAITS; 
 see innodb Run time information for the engine 
show engine innodb status\G;
 See what caused the deadlock sql sentence , Analyze the index situation , And then optimize sql sentence ;
 
 View server status 
show status like '%lock%';
 Check the timeout ：
show variables like '%timeout%';