Sql deadlock trying to drop a datbase9/27/2023 WITH CHECK ADD CONSTRAINT FOREIGN KEY(, ) )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON ĪLTER TABLE. In the detail table, include the IdPartition column to maintain the same referential integrity with header table.ĬONSTRAINT PRIMARY KEY CLUSTERED.WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON () WITH (SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, ONLINE = OFF) ON ()Ĭreate UNIQUE nonclustered INDEX ON. Second, include the PK to have the referential integrity with Detail table.ĬREATE CLUSTERED INDEX ON.For the table header perform two operations:.Create the partition schema based on the function defined:ĬREATE PARTITION SCHEME AS PARTITION TO (,, ,, ,, ,, ,, ,, ,, ,, ,,.Create a partition function for the 32 threads, running the following command:ĬREATE PARTITION FUNCTION (int) AS RANGE RIGHT FOR VALUES (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17.32).My suggestion suggested was to create a partitioned table based on the numbers of threads, for example: Create a new Partition Key based on the number of threads running.Retry the operation about the transaction that was killed by SQL Server.We saw that the deadlock is happening when these a transaction needs to lock a resource that the other transaction has in exclusive mode.SQL Server handles deadlocks by terminating and rolling back transactions that were started after the first transaction. During the execution we saw some deadlocks because 2 transactions block each other from continuing because each has locked a database resource that the other transaction needs.This operation is running by 32 threads at the same time. In our customer code, they create a transaction that insert a new row in the header table and after insert around 1000 rows in the detail table.Our customer has two tables with the following structure:ĬONSTRAINT PRIMARY KEY CLUSTERED()ĬONSTRAINT PRIMARY KEY CLUSTERED(),.I saw an important thing that may prevent a deadlock. Post a question with the problem queries and/or the deadlock trace output and theres a good chance you'll get an explanation as to why its occurring and how it could be fixed.This week I worked on a very interesting service request about a deadlock issue when our customer is running 32 threads at the same time inserting data. As the others have said, you cannot automatically force a retry. If you consistently see a deadlock occuring from the queries issued from page A and page B, you can influence which page results in an error and which completes successfully. Looking at your example in the comment to Mitch's answer: If you can identify the queries involved in the deadlocks, you can influence which of the queries involved are rolled back and which continue by setting DEADLOCK_PRIORITY for each query, batch or stored procedure. One option in addition to those suggsted by Mitch and Remus, as your comments suggest you're looking for a fast fix. See Using Row Versioning-based Isolation Levels. You may also consider using snapshot isolation, since the lock-free reads involved in snapshot reduce the surface on which deadlocks can occur (ie. There are many, many resources out there on how to identify and solve deadlocks: Some problems will send you back to the drawing board and you will have to rethink your requirements. Many problems will be solved by deploying appropriate indexes. While is true that other types of deadlock can occur, I bet is not your case. Invariably, the cause will turn out to be queries that scan more data that they should. Your only focus should be at figuring out why the deadlocks occur and eliminate the cause. If your process has deadlocked, by definition another process has won the deadlocks, and it meas it has changed something you've read. The very definition of deadlock is that the state you base your decision on has changed therefore you need to read again the state and make a new decision. You will never succeed in doing automated deadlock retries by the SQL engine, such concept is fundamentally wrong.
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