Improve this question. Marmite Bomber Add a comment. Active Oldest Votes. You could also use a merge instead of an update, e.
Improve this answer. Alex Poole Alex Poole k 9 9 gold badges silver badges bronze badges. Thank you! And yes, I have multiple IDs and will make an update on that. For now, I was just trying to get one to work. I appreciate it : — JMC. Marmite Bomber Marmite Bomber Sign up or log in Sign up using Google. Sign up using Facebook. It does not see any of the uncommitted changes made by the main transaction and does not share any locks or resources with the main transaction.
Changes made by an autonomous transaction become visible to other transactions upon commit of the autonomous transactions. Thanks for all your help. Best Regards. August 25, - am UTC. It would be like trying to pick the cloned sheep daisy out of a herd of sheep. Unless you yourself placed daisy in the herd, you would have no clue which one was she. Hi Tom, With all the respect to you, don't get me wrong I only want to know if autonomous transaction opens another session or uses the same session.
I feel it uses same session still we have people with different opinions just wanted to know the right thing. Thanks as always for your helps It is just like "recursive sql", you've been doing autonomous transactions for years -- you just never knew it.
Dead lock Dillip K. Praharaj, October 22, - pm UTC. October 22, - pm UTC. What did you want it to do? Trust me I would not like to wait. Thanks for the clarification. Tom: We are creating an web application. Now, question is: When more than one users work on same record, only the first one who selects the record can update it. The rest of users are view only for this record. Does Oracle has such function? Do you have any other solutions? Thank you for your helps.
November 07, - am UTC. This software does not use sequences to generate unique numbers for their tables. So, then two sessions might return the same value Is there a more robust way to do this? May 26, - am UTC. Do we have to raise an error? An error would stop all the processing The caller will FAIL anyway. You'll have moved the error elsewhere. Do you really have code that is expected to call this with an undefined sequence value????
The nextkey table is owned by this third party software Considering this is a batch process that will run overnight.. We do want to know that a record could not be inserted because.. May 26, - pm UTC. A reader, November 01, - pm UTC. Tom, I've read your book It is said that deadlocks are very rare, harmless unless there is unindexed fk. Then, it is contrary to the Oracle principle that commit should be delayed But why did your example result in a deadlock?
November 02, - am UTC. That "deadlock" was a "self deadlock". That is not a real world "issue" here, if this happens in your application via the use of autonomous transaction that is most definitely an "application bug". You did it to yourself. Not at all. The only principle is that a transaction should be: a as short as it can be b AS LONG AS IT NEEDS that is, do not commit a partial transaction "because it is easier on the database" -- that would be a really bad idea but a common practice in many other databases -- a very very bad practice.
You commit immediately after executing the last statement in the series of statements that constitute your transaction. Not a moment before 2 i never got a test case, an example, so there is nothing i can clarify. You cannot "block yourself" indefinitely -- it would just sit there forever! A reader, November 02, - pm UTC. Hi Tom, When will an insert statement cause a deadlocked session?
Also, update and delete statements. Please give some examples Also, can a column have a unique as well as nonunique key set on it? November 03, - am UTC. Tom, Strangely, why wouldn't the script that detects unindexed foreign keys from your site wouldn't show one unindexed foreign key even though there is one! Sorry, please ignore above post. I realized the column was not fk at all.
Tom, 1. Will deadlock occur only when plain sql statements are used? I have a deadlock scenario where a user interface is deadlocking with some process, and I looked at all the queries related to deadlock only the deadlock queries. And I come to a conclusion that the application s are not using locking.
Especially the user interface application is not using locking at all becuse I see plain sql statements in it. All the foreign keys are indexed. Could you please comment? A reader, November 03, - am UTC. Tom, The plain sqls I talked about are simple select statements with no for update, wait, nowait clauses.
One application that is involved in deadlocks is using such sqls. All the queries use bind variables. The select statement is used only as a part of 'insert into select x, y, z from I think there is no intention for locking. I agree locks are necessary for deadlocks but the sqls doesn't seem to acquire locks.
Then how is it possible that deadlocks are occuring despite the reason that deadlocks are rare, will be taken care etc Why are the inserts and updates resulting in deadlocks? What could the other app process be doing? Any comments will be helpful and appreciated. How presence of primary key affects locking behaviour on block level? November 04, - am UTC. A reader, November 22, - pm UTC. Will, December 06, - am UTC. Hi Tom, I've learned a lot about locking from reading your books. BookingPK; Does that result in an update of the primary key?
It certainly looks like it. Would you consider this to be an unsound way to use rowtype? How could I improve on it?
December 06, - am UTC. Our examples in this guide will show you how to update the person. This method is slightly different to the previous two. The join is performed in the Update clause, and not in the From clause.
The Select query inside the Update statement looks up the two tables and constructs the right data set to use. Then the Set clause will set the person account number to the account number value. This will happen depending on the tables and query that you have.
Creating primary keys on the table may still result in this error. This query will look up the right account number to use in the subquery, which joins to the outer person table and return it to the SET clause. Updating data in one table based on data in another table is something you may do occasionally. Your email address will not be published. Notify me of follow-up comments by email.
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