There are a few different ways to manage large quantities of text in a
database. The previous examples given for the REPORT table
concentrated on the VARCHAR (variable length character) column which
held a filename as a character string; e.g.,
as stored in the FILENAME column. This column manages the filename
only, not the text contained in that file.
In the examples used in Chapter here, Table Definition, a RESUME table is created which uses a VARCHAR field of around 2000 characters to hold the text of the resumes. In this case, the job experience text of each resume is stored in the column EXP. A Load Program would be used to insert text of this length into the column of a table.
Another way Texis has of managing text is to allow the files to remain
outside the confines of the table. Where the INDIRECT data type is
used, a filename can be entered as a value which points to an actual
file, rather than treated as a character string. The INDIRECT type
looks at the contents of the file when doing
LIKE, and these contents
can be retrieved using the API (Application Program Interface).
The form of the INSERT INTO command is the same as above. Where a
data type is defined as
INDIRECT, a filename may be entered as the
value of one or more columns.
Example: Let's say we have the following information available for a resume to be entered into the RESUME table, and that the job experience column EXP has been defined as INDIRECT.
RES_ID = R421
RNAME = Smith, James
JOB = Jr Analyst
EDUC = B.A. 1982 Radford University
EXP = contained in the resume file "/usr/local/resume/smith.res"
Use this INSERT INTO statement to add a row containing this information to the RESUME table:
INSERT INTO RESUME
VALUES ('R421','Smith, James','Jr Analyst',
'B.A. 1982 Radford University',
The EXP column acts as a pointer to the full text files containing the
resumes. As such, the text in those files responds to all
WHERE statements. Thus Metamorph queries used after
can be done on the text content manipulated by Texis in this table.