python - Should I use MySQL Lock Table or there exists better solution? -


I am working on a multi-processing application, and each process sometimes executes the following code:

Code> db_cursor.execute ("Select from MAX (id)" for record in pd

And I am facing the following problem: There can be a situation when two processes take the same maximum value, and both try to delete this value We do. Such a situation is not acceptable in the context of my application, each value should be taken only by one process (and removed)

How can I get it? Is there a good way to lock the table while taking the maximum maximum or delete it altogether or do it?

Thank you. Record with

GET_LOCK () ;

If you want to lock the lock, select the specific name for which you want to lock. Like 'prqueue_max_del' . Call SELECT GET_LOCK ('prqueue_max_del', 30) to lock the name to 'prqueue_max_del' . It will return 1 and set the lock if the name is available, or 0 if the lock is not available after 30 seconds (second parameter Timeout).

Use SELECT RELEASE_LOCK ('Prqueue_max_del') You will end up.

You must use the same name in each transaction and you must call GET_LOCK () in the transaction first set lock.

Beware; Since only the abstract name is closed, all other processes are not using this method and the abstract name, will be able to waste your table independently.


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