What is the difference between Update Lock and Exclusive Lock? An Update Lock can sit on a row that has a Shared Lock, then turns Exclusive when it writes.
Following a Blocking Chain to the Head Blocker
Follow SQL Server blocking_session_id through a blocking chain, identify the head blocker, and choose a safe ending for the wait.
High-Frequency Inserts Without Blocking
High-frequency inserts can stall on the log, indexes, or last-page contention; learn to diagnose the wait and choose targeted SQL Server fixes.
Finding Sleeping Sessions That Still Hold Locks
Find sleeping sessions with open transactions, inspect their locks and last batch, and identify the application owner before ending work.
Preventing Overbooking When Two Sessions Grab the Last Seat
Learn preventing overbooking through a last-seat race, an atomic update, update locks, and a database constraint that rejects oversold inventory.
Reviewing a Table Change Script Before It Locks Production
Review a table change script for schema locks, data rewrites, supported online options, backfill batches, and a tested rollback.
The Blocked Process Report
The blocked process report shows the waiting session and blocker after a configured threshold, with Extended Events capturing the XML for review.