Pages in least-recently used order

When the database server processes a request to read a page from disk, it must decide which page to replace in memory.

Rather than select a page randomly, the database server assumes that recently referenced pages are more likely to be referenced in the future than pages that it has not referenced for some time. Thus, rather than replacing a recently accessed page, the database server replaces a least-recently accessed page. By maintaining pages in least-recently to most-recently used order, the database server can easily locate the least-recently used pages in memory.