Dec 092017
 
A discussion on how Paradox tables can become corrupt.
File CORUPT.ZIP from The Programmer’s Corner in
Category Paradox DBMS
A discussion on how Paradox tables can become corrupt.
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Contents of the CORUPT.TXT file


There are a huge number of things that can cause a corrupted table. This
is not due to any problems with Paradox, but rather is a unfortunate
part of operating in a DOS enviornment with minimal error checking and
write redundancy. Below are a list of things that can cause a table to
be corrupted. They are arranged roughly by how frequently the errors
occur:
Operator Error - Turning off or rebooting the computer while Paradox is
on screen. Just because there are no images on the screen does not mean
it is OK to shut the system down, as parts of the table may remain only
in RAM. ALWAYS exit Paradox to DOS before rebooting or powering down.

Hard or Floppy Disk Errors - Any time a disk is not operating up to
spec, one of the first signs is corrupted tables. Any failure to read or
write to the media properly can damage a table. A bad controler card can
also cause problems.

A.C. Voltage Variations - Black out, brown out, line "spikes" (very
short very high votage increases), line "Dips" (short duration voltage
reduction; example HP Laserjet II places power dips on line and corrupts
Paradox tables. A computer with a power supply that is too weak (amps)
for all the boards or devices connected to it can generate a voltage
that is too low, causing corruption.

RAM Problems - Parity errors in memory chips, CPU speed set higher than
the memory can refresh (appears to be a problem in some high speed
clones), an extended memory board in the machine that has NOT been
INITIALIZED (via the s/w provided by the board manufacturer),

Unexpected Condition Errors - It is impossible to say in many cases
which comes first the error (U.C.) or the corruption. In any case, if
you get a U.C. error, the table(s) in use will usually need Rebuilding
with Tutility.

TSR Programs - Programs that run in the "backround" are sometimes
"illmannered" about the way they return control to the main program. If
the program does not restore the bus and RAM back to the original state,
this can cause corruption. Even poping up a TSR at a bad time (in the
middle of a sort for instance) can cause problems.

Network Problems - A malfunctioning server, bad cable connector, bad I/O
RAM, bad packet transmission (interference), malfunctioning network
board, or even a net line that is too long can all be responsable for
corrupted tables.
-
There may be other things that will cause corruption as well, but I
think this list may give you a place to start. If you want more
information about how to solve the problem, please message me.
Go Get'um - Chip


 December 9, 2017  Add comments

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