Query Description

Demonstrates DBQ relational capabilities using a demo Invoice/Billing application that consists of 6 files with indexes. All the files were already added to the Data Dictionary same as in the first example.

- Display all the records from the 6 files for the city of Dallas

- Order the results by invoice date, invoice number and line number

- Produce a report using a pre-defined format called inv_cust.fmt

- Show the Status screen every 50 records read

The status screen shows the internal activity of DBQ, which files were used and whether optimization was used or not, and what index was used. This screen can be automatically displayed while the query is executing and also at the end of the query. This status screen serves as a "window" into DBQ "Atricitial Inteligence"

The information in the status screen consists of the total number of records read, the start and end time and for each file the optimization the was used, ie. Whether an index was used and how. The Customer file was accessed sequentially since there's no index on the city field. But all the other files were indexed accessed and the screen also shows what part of the index was used, how many records from file were read and how many were used in the result file.

Invoice Customer Report Format