MySQL Can aborting a query with Ctrl-C harm the table?
Q :Can aborting queries harm the column that the query was operating on? If so, how can I recover from the problem?
A : If the transaction wasn’t completed, no. MySQL does ALTER TABLE by creating a new table and then updates the reference to the old table. You shouldn’t have altered your original table if you interrupted the original ALTER TABLE query.
The easiest way to terminate a renegade query is to use the MySQL shell as the root user:
This will give you a list of the current connections and a process ID for each one. To terminate any given query, such as number 19, use:
Usually this will undo and roll back the query.