Databases Reference
In-Depth Information
a database and application server. This puts an added load on all resources,
including the hard disk.
Disk fragmentation can impair disk performance, though it usually isn't con-
sidered a bottleneck in itself and often isn't a serious issue in database systems.
Fragmentation occurs when files are broken up into smaller pieces to use
available disk space. The more you delete and create files, the faster the drive
fragments. Most computers create and delete more files than you would suspect,
many of them temporary files used by applications and deleted when no longer
needed.
Disk fragmentation is less of an issue for database servers than for comput-
ers operating in other roles. In a well-designed database system, the database
files are kept somewhat segregated from other files, often on their own drive.
Because you are protecting the database files, they are more likely to remain con-
tiguous, minimizing the potential impact if other files become fragmented.
Microsoft Windows ships with Defrag.exe, a disk defragmentation utility,
which physically moves the file segments so that they form contiguous files. You
can also launch the disk defragmenter via the Computer Management console,
as shown in Figure 8-2.
Figure 8-2
Disk defragmenter.
