Uploaded at the request of Anthony K. Lima

Question by Pickles, July 25, 1991.

PI-->I wrote an application for the department of a bank some time ago, their
  -->business for this application has increased considerably. Now one of
  -->their daily reports is taking 50 mins. to run. I've tried to get them
  -->to upgrade to db4 and/or get a 386 instead of the 286 that they have.
  -->The are dragging their feet because of budget constraints and what not.
  -->Would it help MUCH if it was compiled into Clipper?

Response by Chalmer: 

Based on my experience, the way to speed up dBASE III Plus processing 
depends on a number of factors.  Assuming a constant size dbf and ndx:

1.  Printer speed.  Is you computer waiting on the printer?  If so, then
speeding up the processing won't do you any good until they get a faster
printer.  If that's not possible, maybe print the reports to a file, and
then after the processing is done, use the DOS PRINT command to print
the files in the background (maybe with a BAT file if there are several
files) while the user goes on about the rest of the processing.  Or
maybe use a print spooler subsystem.

2.  Speed of hard disk.  65 - 85 ms = standard XT (8088/8086 machines).
40 ms = standard AT (80286 machines).  25 - 30 ms = fast AT. 17 - 20 ms
= really fast AT or common on a 80386.  Less than 17 ms = fast 80386.  
If you can't replace the AT computer, can you replace the hard disk and
controller?

3.  System hard disk cache for 80286 with extended memory.  Included with
DOS 5.0, Windows 3.0, Norton Utilities Version 6, PC Tools versions 6 and 7.
Hyperdisk shareware available on this BBS.  Best results if your client
has at least 2 mb of total RAM.

4.  CPU type/speed.  Moving from a 80286-6 (original IBM AT) to an
80286-16 or 80286-20 will speed things up a lot, if you're not bound
by disk speed or printer speed.  Some 286 machines can be upgraded
simply by changing the CPU chip to a faster chip.

5. Dumb or inefficient dBASE programming.  Don't use LOCATE if you can
use SEEK or FIND.  Don't PACK until you must.  Don't REINDEX until you
must.  Etc.

6.  Number of prg files.  If you have dozens of prg files, combine them
into one main menu file, and only one or two other files with your
programs and procedures.  Then use the SET PROCEDURE TO <filename>
command to make the other procedures available to the main menu.  There 
is a limitation on the number of procedures you can have in one procedure 
file, so you may need more than one or two files if you have bunches of 
procedures.

7.  Compile with Clipper.  This will help a little, if you're not disk
or printer bound.  But only if you have huge or complex prg files.  The
real reason for Clipper is to hide your source code from thieves, but
it will also speed up processing slightly.  After you've done everything
in 1 thru 6, you won't notice much speed improvement with Clipper.


Chalmer Wren, Jr.
Defense Finance and Accounting Service - Denver Center