Why am I seeing a 'general error 1205 lock wait timout exceeded' in my Magento project?

Question

I have a multi store Magento web project. There I need to specify the categories for each and every store views in catalog --> manage categories. It was working fine, but from today itself suddenly it stopped working.

I can edit the categories, if the store view is "All store views".

If I switch it to any other store, such as store1, I can't make any change.

I have unchecked "default value tab", then if I choose Is Active --> NO, the default please wait loader will appear, and after some time the page throws an error:

SQLSTATE[HY000]: General error: 1205 Lock wait timeout exceeded; try restarting transaction.

I am attaching a screenshot here

Why is it so?

Answer 1

I found the solution, I went to the phpmyadmin and run this query in sql,

SET innodb_lock_wait_timeout =120

and everything went all right. Thanks guys.