Databases Reference
In-Depth Information
is little you can do to reduce memory requirements. That leaves increasing mem-
ory, typically installing more system memory.
Before installing memory, however, check the database and operating system
configuration to see how memory is being used. With some DBMSs, such as SQL
Server, you can specify the amount of memory made available to database oper-
ations. This could place an artificial limit on memory, causing a memory bottle-
neck, even though there is more physical memory available.
As mentioned before, memory directly impacts disk use. Modern operating
systems increase available memory through use of a virtual memory
paging file.
This is hard disk space that is set aside and used like system memory. Paging is
the process of moving data between system memory and the paging file, as
shown in Figure 8-4. When physical RAM memory doesn't meet your memory
requirements, paging increases, interfering with other disk operations and mak-
ing the hard disk look like your bottleneck.
Understanding Processor Issues
Every program that runs, every query that is executed, every module called from
your application—all these put an additional load on the system processor. To
Figure 8-4
System memory
Paging file
Hard disk
Paging.
