Essay/Term paper: Brief history of databases

Essay, term paper, research paper:  Information Technology

Brief History Of Databases


In the 1960's, the use of main frame computers became widespread in many
companies. To access vast amounts of stored information, these companies
started to use computer programs like COBOL and FORTRAN. Data accessibility and
data sharing soon became an important feature because of the large amount of
information recquired by different departments within certain companies. With
this system, each application owns its own data files. The problems thus
associated with this type of file processing was uncontrolled redundancy,
inconsistent data, inflexibility, poor enforcement of standards, and low
programmer maintenance.
In 1964, MIS (Management Information Systems) was introduced. This
would prove to be very influential towards future designs of computer systems
and the methods they will use in manipulating data.
In 1966, Philip Kotler had the first description of how managers could
benefit from the powerful capabilities of the electronic computer as a
management tool.
In 1969, Berson developed a marketing information system for marketing
research. In 1970, the Montgomery urban model was developed stressing the
quantitative aspect of management by highlighting a data bank, a model bank, and
a measurement statistics bank. All of these factors will be influential on
future models of storing data in a pool. According to Martine, in 1981, a
database is a shared collection of interrelated data designed to meet the needs
of multiple types of end users. The data is stored in one location so that they
are independent of the programs that use them, keeping in mind data integrity
with respect to the approaches to adding new data, modifying data, and
retrieving existing data. A database is shared and perceived differently by
multiple users. This leads to the arrival of Database Management Systems.
These systems first appeared around the 1970=s as solutions to problems
associated with mainframe computers. Originally, pre-database programs accessed
their own data files. Consequently, similar data had to be stored in other
areas where that certain piece of information was relevant. Simple things like
addresses were stored in customer information files, accounts receivable records,
and so on. This created redundancy and inefficiency. Updating files, like
storing files, was also a problem. When a customer=s address changed, all the
fields where that customer=s address was stored had to be changed. If a field
happened to be missed, then an inconsistency was created. When requests to
develop new ways to manipulate and summarize data arose, it only added to the
problem of having files attached to specific applications. New system design
had to be done, including new programs and new data file storage methods. The
close connection between data files and programs sent the costs for storage and
maintenance soaring. This combined with an inflexible method of the kinds of
data that could be extracted, arose the need to design an effective and
efficient system.
Here is where Database Management Systems helped restore order to a
system of inefficiency. Instead of having separate files for each program, one
single collection of information was kept, a database. Now, many programs,
known as a database manager, could access one database with the confidence of
knowing that it is accessing up to date and exclusive information.



Some early DBMS=s consisted of:
Condor 3 dBaseIII Knowledgeman Omnifile Please Power-Base R-Base 4000 Condor 3,
dBaseIII, and Omnifile will be examined more closely.

Condor 3
Is a relational database management system that evolved in the
microcomputer environment since 1977. Condor provides multi-file, menu-driven
relational capabilities and a flexible command language. By using a word
processor, due to the absence of a text editor, frequently used commands can
automated.
Condor 3 is an application development tool for multiple-file databases.
Although it lacks some of the capabilities like procedure repetition, it makes
up for it with its ease to use and quick decent speed.
Condor 3 utilizes the advantages of menu-driven design. Its portability
enables it to import and export data files in five different ASCII formats.
Defining file structures is a relatively straightforward method by typing the
field names and their length, the main part of designing the structure is about
complete. Condor uses six data types:

alphabetic alphanumeric C. numeric C. decimal numeric C. Julian
date C. dollar
Once the fields have been designed, data entry is as easy as pressing
enter and inputting the respective values to the appropriate fields and like the
newer databases, Condor too can use the Update, Delete, Insert, and Backspace
commands. Accessing data is done by creating an index. The index can be used
to perform sorts and arithmetic.

dBaseIII
DbaseIII is a relational DBMS which was partially built on dbaseII.
Like Condor 3, dbaseIII is menu-driven and has its menus built in several levels.
One of the problems discovered, was that higher level commands were not
included in all menu levels. That is, dBaseIII is limited to only basic
commands and anything above that is not supported. Many of the basic
capabilities are easy to use, but like Condor, dBaseIII has inconsistencies and
inefficiency. The keys used to move and select items in specific menus are not
always consistent through out. If you mark an item to be selected from a list,
once it=s marked it can not be unmarked. The only way to correct this is to
start over and enter everything again. This is time consuming and obviously
inefficient. Although the menus are helpful and guide you through the stages or
levels, there is the option to turn off the menus and work at a little faster
rate.
DBaseIII=s command are procedural (function oriented) and flexible. It
utilizes many of the common functions like: select records C. select fields C.
include expressions ( such as calculations) C. redirect output to the
screen or to the printer C. store results separately from the application
Included in dBaseIII is a limited editor which will let you create
commands using the editor or a word processor. Unfortunately, it is still
limited to certain commands, for example, it can not create move or copy
commands. It also has a screen design package which enables you to design how
you want your screen to look. The minimum RAM requirement of 256k for this
package really illustrates how old this application is. The most noticeable
problem documented about dBaseIII is inability to edit command lines. If, for
example, an error was made entering the name and address of a customer, simply
backing up and correcting the wrong character is impossible without deleting
everything up to the correction and re-entering everything again.
DBaseIII is portable and straightforward to work with. It allows users
to import and export files in two forms: fixed-length fields and delimited
fields. It can also perform dBaseII conversions. Creating file structures are
simple using the menus or the create command. It has field types that are still
being used today by applications such as Microsoft Access, for example, numeric
fields and memo fields which let you enter sentences or pieces of information,
like a customer=s address, which might vary in length from record to record.
Unlike Condor 3, dBaseIII is able to edit fields without having to start over.
Inserting new fields or deleting old fields can be done quite easily.
Data manipulation and query is very accessible through a number of
built-in functions. The list and display commands enable you to see the entire
file, selected records, and selected files. The browse command allows you to
scroll through all the fields inserting or editing records at the same time.
Calculation functions like sum, average, count, and total allow you to perform
arithmetic operations on data in a file. There are other functions available
like date and time functions, rounding, and formatting.

Omnifile
Omnifile is a single-file database system. This database is form
oriented meaning that it has a master form with alternate forms attached to it.
Therefore, you can work with one file and all of its subsets at the same time.
The idea of alternating forms provides for a greater level of security, for
example, if a user needed to update an address field, they would not be able to
access any fields which displayed confidential information. The field in need
of updating would only display the necessary or relevant information.
Menus are once again present and used as a guide. The use of function
keys allows the user to move about screens or forms quite easily. Menus are
also used for transferring information, either for importing or for exporting.
One inflexibility noted was that when copying files the two files must have the
exact same fields in the same order as the master file. This can be problem if
you want to copy identical fields from different files.

Forms design is simple but tedious. Although it may seem flexible to be
able to paint the screen in any manner that you wish, it can be time consuming
because no default screen is available. Like other database management systems,
the usual syntax for defining fields apply, field name followed by the length of
the field in braces. However, editing is a little more difficult. Changing the
form can be done by inserting and deleting, one character at a time. Omnifile
does not support moving fields around, nor inserting blank lines. This means
that if a field was to be added at the beginning of the record, the entire
record would have to be re-entered.
Records are added and viewed in the format that the user first designed
it. Invalid entries are not handled very well. Entering an illegal value in a
certain field results in a beep and no message, the user is left there to try
and decide what the error is. Omnifile does support the ability to insert new
records while viewing existing records and to make global or local changes.
Querying can be performed by using an index or using a non-indexed
search. If a search for a partial entry is made like ARob@ instead of
ARobinson@, a message is then displayed stating that not an exact match was
found. Overall These are just a few of the database programs that help start the
whole database management system era. It is apparent that DBMS=s today still
use some of the fundamentals first implemented by these >old= systems. Items
like menus, forms, and portability are still key parts to current applications.
However, programs have come along since then, but still have as their bases the
same fundamental principles.