Datasheet

❑ Vendor commitment — Without the widespread buy-in of vendors to build drivers/providers
for their products, any universal data access model wouldn’t be universal. Microsoft could
provide the drivers for some of the most common vendor products, but it really takes an open,
easily extensible model in order to gain widespread acceptance. No matter how much companies
try to avoid it, almost all of them become “locked-in” to at least a handful of vendors. Switching
to a vendor that supports the latest data access components is not really an option, so without
widespread buy-in from vendors, a data access model cannot succeed.
❑ Broad industry support — This factor is along the same lines as vendor commitment, but
includes a wider arena. It takes more than the data access model to be able to easily create good
applications with it; it also requires good tools that can work with the data access model.
Furthermore, it requires backing by several big players in the industry to reassure the masses. It
also requires highly skilled people available to offer training. Finally, of course, it requires willing
adoption by the development community so employers can find employees with experience.
Steady progress has been made, improving databases and universal data access over the last few
decades. As with any field, it’s important to know where we’ve come from in database and data access
technologies in order to understand where the fields are heading. The following section looks at some
early achievements.
The Early Days
In the 1950s and early 1960s, data access and storage was relatively simple for most people. While more
advanced projects were under development and in use by a limited number of people, the majority of
developers still stored data in flat text files. These were usually fixed-width files, and accessing them
required no more than the capability to read and write files. Although this was a very simple technique
for storing data, it didn’t take too long to realize it wasn’t the most efficient method in most cases.
CODASYL
As with the Internet, databases as we know them today began with the U.S. Department of Defense. In
1957, the U.S. Department of Defense founded the Conference on Data Systems Languages, commonly
known as CODASYL, to develop computer programming languages. CODASYL is most famous for the
creation of the COBOL programming language, but many people don’t know that CODASYL is also
responsible for the creation of the first modern database.
On June 10, 1963, two divisions of the U.S. Department of Defense held a conference titled
“Development and Management of a Computer-Centered Data Base.” At this conference, the term
database was coined and defined as follows:
A set of files (tables), where a file is an ordered collection of entries
(rows) and an entry consists of a key or keys and data.
Two years later, in 1965, CODASYL formed a group called the List Processing Task Force, which later
became the Data Base Task Group. The Data Base Task Group released an important report in 1971 out-
lining the Network Data Model, also known as the CODASYL Data Model or DBTG Data Model. This data
model defined several key concepts of a database, including the following:
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