Everybody knows NOLOCK, but not everyone knows NOWAIT. A question at a Bangalore User Group session led me to explain how NOWAIT skips waiting on a lock.
sys.dm_os_waiting_tasks: Who Is Waiting Right Now and Why
sys.dm_os_waiting_tasks shows every task that waits right now, what it waits for and who is in the way. This post builds a three-session blocking chain on SQL Server 2025, reads the view, finds the head of the chain and names the locked table.
SET LOCK_TIMEOUT and Error 1222: Waiting Less for Locks
Set LOCK_TIMEOUT to bound lock waits, reproduce error 1222, clean up the transaction, and retry safely without confusing client timeouts.
Loading Partitions in Parallel
Loading partitions in parallel uses separate staging tables, controlled workers, and partition switching to publish data without chaotic locks.
Blocking and Deadlock Quiz: Which One Ends by Itself?
This Blocking and Deadlock Quiz asks which problem SQL Server ends on its own, and how the losing session finds out. A two-window test on SQL Server 2025 shows the deadlock error 1205 and the lock timeout error 1222. It also shows how to find a blocker and how to retry.
Locking and Blocking Quiz: Will Updating a Different Row Wait?
This Locking and Blocking Quiz asks whether an update waits when it changes a different row than an open transaction. The answer depends on the index. A two-window test on SQL Server 2025 shows the wait, the lock that causes it, and two ways to remove it.
ANSI Isolation Levels Quiz: Which Level Lets You Read Uncommitted Data?
This ANSI Isolation Levels Quiz asks which level lets one session read a price that another session has not committed. A two-window test on SQL Server 2025 shows what each level returns. It also shows how READ COMMITTED SNAPSHOT removes the wait.