Handling SQL Server Deadlocks during Bulk Insert Operations with Triggers
Hey everyone, I'm running into an issue that's driving me crazy. I'm working on a personal project and I'm currently working with an scenario with SQL Server 2019 where a deadlock occurs during bulk insert operations that activate triggers on the target table. The scenario is as follows: I’m executing a bulk insert into the `Orders` table, which has a trigger that updates the `Inventory` table for each inserted order. This leads to deadlocks, especially when multiple users are running the bulk insert simultaneously. I’ve tried several approaches to mitigate this, including changing the transaction isolation level to `READ UNCOMMITTED` for the bulk insert, but it hasn't resolved the deadlock scenario. Here's the code I'm using for the bulk insert: ```sql BULK INSERT Orders FROM 'C:\Data\orders.csv' WITH ( FIELDTERMINATOR = ',', ROWTERMINATOR = '\n', FIRSTROW = 2 ); ``` The trigger on the `Orders` table looks like this: ```sql CREATE TRIGGER trg_UpdateInventory ON Orders AFTER INSERT AS BEGIN UPDATE Inventory SET Quantity = Quantity - inserted.Quantity FROM inserted WHERE Inventory.ProductID = inserted.ProductID; END; ``` I also checked the execution plan and noticed that both the `Orders` and `Inventory` tables are being locked during the operation. I've read that using `NOLOCK` hints can help, but I'm unsure how to properly implement them without risking data integrity. Moreover, I’m receiving the following behavior message when the deadlock occurs: ``` Transaction (Process ID 123) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction. ``` What are some best practices or alternative strategies I can implement to avoid deadlocks in this situation, particularly when using triggers alongside bulk inserts? This is part of a larger microservice I'm building. Thanks in advance! Thanks, I really appreciate it!