Dictionary/3000 Reference Manual (32244-90001)

332 AppendixD
How HP INFORM Links Files to Generate Reports
Indirect Links
Suppose the report requests the data element “occupied” from the detail set
COMMERCIAL and the data element “city-name” from the master set CITY-MASTER.
An indirect link can be formed by going through the detail set RESIDENTIAL. The
detail set COMMERCIAL and the detail set RESIDENTIAL both have the search item
“list-price” (which forms IMAGE paths to the common master set LIST-PRICE-MSTR);
the detail set RESIDENTIAL has a second search item “city-abbr” which forms an
IMAGE path to the master set CITY-MASTER.
As stated earlier, these are the only two indirect links which HP Inform/3000 allows and
both apply only to data sets within one database.
The Driving File
The driving file is the file that is accessed first. Since at least one line of the report will be
generated for each record retrieved from the driving file, the contents of a report could be
quite different if the driving file is different. Files which meet the following criteria are
considered:
1. the file must contain an element having a positive link value (greater than zero) which
may or may not be included in the report, and
2. the file must contain an element to be included in the report.
One, none, or more than one file might meet the above criteria:
• If only one file meets these two criteria, then it will be chosen as the driving file.
*search items
*list-price
.
.
.
.
LIST-PRICE-MSTR
*list-price
occupied
COMMERCIAL
*city-abbr
*list-price
RESIDENTIAL
*city-abbr
city-name
.
.
.
CITY-MASTER
&sigspace;