SQL Server lock upgrade threshold

Lock upgrade threshold

If you do not use alter table set lock_escalation
When the table lock upgrade is disabled and any of the following conditions are met, the lock upgrade is triggered:

• A single Transact-SQL statement can obtain at least 5,000 locks on a single non-partitioned table or index.

• A single Transact-SQL statement obtains at least 5,000 locks on a single partition of a partitioned table, and alter table set
  The lock_escalation option is set to auto.

• The number of locks in the Database Engine instance exceeds the memory or configuration threshold.

If the lock cannot be upgraded due to a lock conflict, the database engine will trigger the lock upgrade whenever it obtains 1,250 new locks.