Fix : Error 1205 : Transaction (Process ID) was deadlocked on resources with another process and has been chosen as the deadlock victim. Rerun the transaction.
Deadlock occurs when two users have locks on separate objects and each user wants a lock on the other’s object. When this happens, SQL Server ends the deadlock by automatically choosing one and aborting the process, allowing the other process to continue. The aborted transaction is rolled back and an error message is sent to the user of the aborted process. Generally, the transaction that requires the least amount of overhead to rollback is the transaction that is aborted.
Fix/Workaround/Solution:
Deadlock priority can be set by user. In other words, user can choose which process should stop to allow other process to continue. SQL Server automatically chooses the process to terminate which is running completes the circular chain of locks. Sometime, it chooses the process which is running the for shorter period then other process.
To reduce the chance of a deadlock:
- Minimize the size of transaction and transaction times.
- Always access server objects in the same order each time in application.
- Avoid cursors, while loops, or process which requires user input while it is running.
- Reduce lock time in application.
- Use query hints to prevent locking if possible (NoLock, RowLock)
- Select deadlock victim by using SET DEADLOCK_PRIORITY.
SQL SERVER 2005 has new priority HIGH as well as numeric-priority.
SQL SERVER 2005 Syntax
SET DEADLOCK_PRIORITY { LOW | NORMAL | HIGH | <numeric-priority> | @deadlock_var | @deadlock_intvar }
<numeric-priority> ::= { -10 | -9 | -8 | … | 0 | … | 8 | 9 | 10 }
Example:
The following example sets the deadlock priority to NORMAL.
SET DEADLOCK_PRIORITY NORMAL;
GO
Reference : Pinal Dave (https://blog.sqlauthority.com)
