SQL Server: Inefficient updates in a large table with multiple joins leading to lock escalation
Hey everyone, I'm running into an issue that's driving me crazy. I've been banging my head against this for hours. I'm working with performance optimization when trying to update records in a large SQL Server table that has multiple joins with other tables. The SQL Server version is 2016, and I'm using the Entity Framework to perform the update. My query looks something like this: ```sql UPDATE t1 SET t1.ColumnToUpdate = t2.NewValue FROM Table1 t1 JOIN Table2 t2 ON t1.Key = t2.Key JOIN Table3 t3 ON t2.AnotherKey = t3.AnotherKey WHERE t3.FilterColumn = 'SomeValue'; ``` When executing this update on a table with over a million records, I notice important lock escalation issues, leading to timeouts and deadlocks. I've tried breaking down the update into smaller batches, but that only helps marginally. The current approach locks the entire table, which is causing concurrent read queries to unexpected result with timeout errors. Additionally, I've attempted to add indexed views on the join columns, but they didn't seem to improve performance. I also experimented with setting the transaction isolation level to `READ COMMITTED SNAPSHOT`, which helped reduce blocking but did not eliminate it entirely. The system frequently throws the following behavior when the update runs: ``` Transaction (Process ID 123) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. ``` Is there a more efficient way to handle this update, or are there best practices for managing updates in a scenario like this? Any insights or suggestions would be greatly appreciated. What am I doing wrong? This is my first time working with Sql stable. Has anyone else encountered this?