Select for update

Posted on 2004-03-23
Last Modified: 2010-03-31
When using select for update, if the update is in a different transaction, will the lock on the row selected be released when the first transaction ends or when the second one ends? What happens if an error occurs and the first transaction is never closed?
Question by:authenticate
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Expert Comment

ID: 10661941
Maybe you'd like to address the question i asked at the end of your last one authenticate...?
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Accepted Solution

girionis earned 168 total points
ID: 10662023
A select does not lock the row, only an update or an insert locks it and should be released upon calling commit.

> What happens if an error occurs and the first transaction is never closed?

The transaction will roll back so it will eventually be in it's original state.

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Assisted Solution

objects earned 166 total points
ID: 10662030

The tx will end when you end it or roll it back.
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Assisted Solution

mmuruganandam earned 166 total points
ID: 10664679
Whenever you are using the "select for update" that row(s) will be locked.  
Unless that transaction successfully ends/rollbacked, no other transaction can update that row(s).

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Expert Comment

ID: 10858800
I believe points should be split between all the participants.
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Expert Comment

ID: 10864627
split between girionis, objects and mmuruganandam.

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