Microsoft® SQL Server 2012 Unleashed

Row-Level Versus Page-Level Locking

For years, it was often debated whether row-level locking was better than page-level locking. That debate still goes on in some circles. Many people argue that if databases and applications are well designed and tuned, row-level locking is unnecessary. This is borne out somewhat by the number of large and high-volume applications that were developed when row-level locking wasn’t even an option. (Prior to SQL Server version 7, the smallest unit of data that SQL Server could lock was the page.) However, at that time, the page size in SQL Server was only 2KB. With page sizes expanded to 8KB, a greater number of rows (four times as many) can be contained on a single page. Page-level locks on 8KB pages could lead ...