Fig. 17.1.2 The evolution of textual integration into data base technology.The first attempt to manage text was to create a standard field definition and to stuff text
into the definition. Structural definitions such as text field char (1000) were created.
While it is possible to place text in a field such as the one described, there were lots of
problems. Some text entries were much shorter than 1000 bytes (thus wasting space), and
some text entries were much larger than 1000 bytes (creating a complexity). From a size
standpoint alone, merely defining a field of data was not an effective solution. The length
of the field was always either too long or too short (or both).
The next approach by the DBMS vendors was to allow a field called a “blob” to be
defined. The blob would allow any length of text to be entered, thus solving the problem
of defining the length of a field properly. But merely placing text into a blob only solved
one problem of placing text into a database. Once text was placed into a blob, there was
nothing real that could be done with it other than the mere placement of the data into a
database. Trying to do any meaningful analysis on text inside a blob was extremely
difficult to do.
Chapter 17.1: Managing Text