Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Is MySQL UPDATE incrementing operation transaction-safe? I mean could it possible to get into the race condition while many concurrent clients execute queries like “UPDATE table SET field=field+1”? If 1000 clients will execute such query simultaneously, what value that field will be set, 1000 greater than before?
Yes. Each Update statement locks either entire table (MyISAM) or a single row (InnoDB) and other statements are queued until the lock is released.
Now, if you run each of these statements in transaction, you might actually run into a deadlock.