As subsequent queries are executed,
MySQL compares them against the cached queries; if they match, MySQL forgoes
the costly database retrieval and instead simply dumps the cached query result. To
eliminate outdated results, mechanisms are also built in to automatically remove
invalidated cache results and re-cache them upon the next request.
Replication
Version 3.23.15 added MySQL??™s replication feature. Replication allows a database
located within one MySQL server to be duplicated on another MySQL server, which
provides a great number of advantages. For instance, just having a single slave database
in place can greatly increase availability, because it could be immediately brought online
if the master database experiences a problem. If you have multiple machines at your
disposal, client queries can be spread across the master and multiple slaves, considerably
reducing the load that would otherwise be incurred on a single machine. Another
advantage involves backups; rather than take your application offline while a backup
is completed, you could instead execute the backup on a slave, allowing your application
to incur zero down time.
CHAPTER 25 ?– INTRODUCING MYSQL 625
Security
MySQL sports a vast array of security and configuration options, enabling you to
wield total control over just about every imaginable aspect of its operation. For
example, with MySQL??™s configuration options you can control things such as the
following:
??? The daemon owner, default language, default port, location of MySQL??™s data
store, and other key characteristics.
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