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Visual Foxpro or Visual Basic
Message
From
05/06/1998 11:35:31
 
General information
Forum:
Visual FoxPro
Category:
Other
Miscellaneous
Thread ID:
00104962
Message ID:
00105171
Views:
24
relative instability of .dbf tables and index files, especially as this problem
relates to unprotected power supplies.>

In my 13 years of xBASE experience, I have found 99% of corrupted data files ("Not A Database File" message returned upon USE) to be a mismatch between the header record count and actual records saved. Typically what happens is that the header will be updated and written to disk when a new record is added. The data however gets cached. If the power goes off on the machine where the data resides (be it a server or stand-alone), you lose the data giving the mismatch.

All it generally takes to fix the problem is a simple utility (I personally use one that I've had for about 8 years) that re-syncs the header record count back to the actual file length.

As a general rule, if the data server (be it stand-alone or a server) has a UPS so that power is not lost to it, your files will not corrupt.

Indexes are another matter. For the most part, I have no problems unless I've had power outages. I usually rebuild them periodically JIC.<s>

As for DBC's: I had a *bad* experience with one. All I can say is get Stonefield Database Toolkit.<g>
Later...
/< /-/
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