Optimize table lock table?

The mysql version is 5.6 and I use Alibaba Cloud's RDS. I read online before that the optimize table will lock the table. I tested it myself today and it is possible to perform update delete operations during the optimize table.
Excuse me why this is

Another question, how do you know whether a statement/command will lock the table? Is there any way to check the locked table

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The mysql version is 5.6 and I use Alibaba Cloud's RDS. I read online before that the optimize table will lock the table. I tested it myself today. It is possible to perform update delete operations during the optimize table.
Excuse me why this is

Another question, how do you know whether a statement/command will lock the table? Is there any way to check the locked table

show OPEN TABLES where In_use > 0; This SQL statement can check which tables are currently locked
SHOW PROCESSLIST; You can check the currently executing SQL statement and execution status