The page size of the database server's buffer pool must be at least as large as the page size of any database started on that database server. A database server can use a larger page size for the cache, which can be specified using the -gp option. However, in a SQL Anywhere database server, there must be a 1:1 mapping between database pages and page frames in the buffer pool. Each page frame in memory can contain only one database page, and any page may appear in only one page frame. If the cache uses 8 KB pages, but the database uses 4 KB pages, then each cache page frame in memory contains only 4 KB of data, and the other 4 KB of that page frame are wasted. This situation results in a cache size of half the desired amount.
Discuss this page in DocCommentXchange.
|Copyright © 2012, iAnywhere Solutions, Inc. - SQL Anywhere 12.0.1|