© Dmitri Korotkevitch 2016

Dmitri Korotkevitch, Pro SQL Server Internals, 10.1007/978-1-4842-1964-5_20

20. Lock Escalation

Dmitri Korotkevitch

(1)Tampa, Florida, USA

Although row-level locking is great from a concurrency standpoint, it is expensive. In memory, a lock structure uses 64 bytes in 32-bit and 128 bytes in 64-bit operating systems. Keeping information about millions of row- and page-level locks would require SQL Server to allocate gigabytes of RAM to storing them.

SQL Server reduces the number of locks held in memory with a technique called lock escalation, which we will discuss in this chapter.

Lock Escalation Overview

Once a statement acquires at least 5,000 row- and page-level locks on the same object, SQL Server tries to escalate, or ...

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