Last update:
February 4, 1998
Which File Manager should I use: PFM or Btrieve?
Btrieve is a world known, thoroughly tested file manager. The great advantage of Btrieve is that even in case of a power failure and or a similar accident you do not lose data since data is always written to a pre-image file from where data will be automatically retrieved after a power failure. The other advantage is that on a network you run in a client-server mode, therefore reducing net traffic (provided that you use the Btrieve program Brequest). On the down side Btrieve has to be purchased separately and you can use it only in mock flag 0 mode, which is a bit more difficult to learn than mock flag 16 (See the FAQ below for what mock flags are).
PFM is the native Pragma file manager. It is very solid but does not have the safety features of Btrieve. PFM is included in Pragma 5 and supports other mock flag modes.
To sum it up, if data safety is paramount, use Btrieve.
What is the difference between PFM and Btrieve?
When programming in mode 0 ( which is the mode or mock flag we recommend) you are given the choice of using PFM or Btrieve as file managers.
PFM comes with Pragma. It has been tested over years even with monstrous files without any problems. It has one vulnerability: if while writing to PFM the computer shuts down due to a power outing the resulting PFM file may be corrupt.
Btrieve must be purchased separately. It is a known product all over the world and since it writes to a pre-image file before writing to the actual Btrieve file it is safe even when there is an unplanned shutdown of the computer.
An additional advantage of Btrieve is that on a network, using Brequest (a Btrieve product) you operate in a client-server mode thus reducing network traffic.
What are the different mock flags (operating modes) and which should I use?
PFM files have 4 mock flags or operating modes.
Mode 0, also called Btrieve mode, is the mode of choice if you are writing a new application. It is the most versatile since it lets you use PFM files or Btrieve. Although a little more difficult to use than mode 16, the added versatile makes up for this.
Mode 16 is the native PFM mode. It is easier to use than mode 0 but not so versatile.
Mode 1 and 2 should only be used in converted Pragma 3 programs and never in a new application.
For more information consult the "File Managers - Operating Mode" section of the Pragma 5 Manual.
How do I create an empty Btrieve file?
For mock flag 0 Btrieve files, after having defined your Pragma file you must write the description file and then use the utility supplied with Btrieve.
For more information on creating a description file for Btrieve, please consult the File Managers - Btrieve Description File section of the Pragma 5 Manual.
How do I create an empty PFM file?
Mock flag 16 PFM files can be created with the verbs CREATE PFM FILE or EXTERNAL CREATE PFM FILE after you defined your Pragma file.
For mock flag 0 PFM files, after having defined your Pragma file you must write the description file and then use the PRUTIL utility CREATE PFM FILE, in the File menu.
For more information on creating a description file, please
consult the Filemanagers - PFM Description File section of the Various Help.
For more information on the different types of PFM file, please consult the
Filemanagers - PFM Modes section of the Pragma 5 Manual.
How do I create an empty vocab file?
Besides finding an empty vocab file on the Pragma release diskettes, you can create an empty vocab file with the PRUTIL utility CREATE PFM FILE, in the File menu.
Where can I find Btrieve?
Since Btrieve is no longer part of Novell, there has been a lot of confusion on where to find and how to contact Btrieve.
We believe that the following information is correct. Let us know if you have more updated information.
Btrieve now seems to be part of Pervasive Software, located (like the original Btrive company) in Austin, Texas. Their web address is www.btrvtech.com, e-mail address is: info@btrvtech.com.
The European address is:
Gilbert Van Cutsem, Area Manager for Northen Europe
Pervasive Software N.V.
Airport Blvd. Office Park
Bessenveldstraat 25A
B-1831 Diegem
Belgium
Phone +32 (2) 716-4044 Fax +32 (2) 716-4122
E-mail: gvcutsem@pervasive-sw.com
Most of the mail order houses sell Btrieve. There are two of them, located on the East coast of the US:
Programmer's Paradise, New Jersey
http://www.pparadise.com
Phone: (800) 445-7899
The Programmer's Supershop, Massachusetts.
http://www.computing.supershops.com
Phone: (800) 421-8006 (Mon. - Fri.
8:30am - 9:00pm est)
FastFaxts (617) 740-0025
Call them. Usually you get very nice people that are happy to give you the latest information and prices on most software.
