Database Reference
In-Depth Information
In large organizations, processing rights and responsibilities need to
be defined and enforced. What happens, for example, when an employee
leaves the firm? When can the employee's records be deleted? For the pur-
poses of payroll processing, records can be deleted after the last pay pe-
riod. For the purposes of quarterly reporting, they can be deleted at the end
of the quarter. For the purposes of end-of-year tax record processing, they
can be deleted at the end of the year. Clearly, no department can unilaterally
decide when to delete that data. Similar comments pertain to the insertion
and changing of data values. For these and other reasons, security systems
need to be developed that enable only authorized users to take authorized
actions at authorized times.
Databases have become key components of organizational operations,
and even key components of an organization's value. Unfortunately, database
failures and disasters do occur. Thus, effective backup and recovery plans,
techniques, and procedures are essential.
Finally, over time, the DBMS itself will need to be changed to improve
performance by incorporating new features and releases and to conform to
changes made in the underlying operating system. All of this requires atten-
tive management.
To ensure that these problems are addressed and solved, most organi-
zations have a database administration office. We begin with a description
of the tasks of that office. We then describe the combination of software and
manual practices and procedures that are used to perform those tasks. In
Chapter 10 we introduce Chapters 10A, 10B, and 10C, which are the three
chapters that discuss and illustrate features and functions of SQL Server
2012, Oracle Database 11 g Release 2 and MySQL 5.6, respectively, for
dealing with these issues.
The Importance of Working with an Installed DBMS Product
As we discussed in Chapter 7, in order for you to fully understand the DBMS concepts and
features we discuss and illustrate in the chapter, you need to work with them in an installed
DBMS product. You need this hands on experience is necessary so that you move from an ab-
stract understanding of these concepts and features to a practical knowledge of them and how
they are used and implemented.
The information you need to download, install, and use the DBMS products discussed in
this topic is in Chapter 10 (introduction to the DBMS products), Chapter 10A (Microsoft SQL
Server 2012), Chapter 10B (Oracle Database 11 g Release 2). and Chapter 10C (MySQL 5.6).
Portions of these chapters parallel the discussion in this chapter, and illustrate the actual use
of the concepts and features in each DBMS product.
To get the most out of this chapter, you should download and install the DBMS product(s)
of your choice, and then follow along as you work in each section of this chapter by working
through the corresponding sections of the chapter for your DBMS product.
 
 
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