Sql select for update wait

Improve this question. The only way to block a select is to either use for update or to manually lock the entire table in exclusive mode before starting the update. That wasn't my understanding from the docs — ivarec. It will not change anything. Another option you have is to use the serializable isolation level for both the update and the select. It seems to contradict what you just said, but from the docs my understanding is the same as yours.

Do you agree with me or did I misinterpret jjanes' comment? It does not contradict what I said. Why do you think that? Maybe my wording "change" was unfortunate - of course that means "change" in terms of "changing data", i.

Add a comment. Active Oldest Votes. Improve this answer. I don't know which one is right. Can you point me to the documentation that explains this? Maybe I should look in the source code — ivarec. Both will attempt a lock. The first one gets it, the other one waits.

Row lock confliction is symmetric. If necessary, adjust the timeout setting for the connection at the application level. This stored procedure waits for a variable period of time and then returns information to the user as the elapsed numbers of hours, minutes, and seconds. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. In this example we select a student row and wait up to 15 seconds for another session to release their lock:.

Rather, they ensure data integrity by re-reading the data when the end-user requests a change, and displays an error message if the data has changed since it was initially displayed to the user. Burleson is the American Team Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals. Feel free to ask questions on our Oracle forum. Verify experience!