How do transactions protect against file damage? 
Author Message
 How do transactions protect against file damage?

I work at a company as a systems administrator and programmer, and we have
struggled with that issue for a long time. The solution is many folds. We
choose to go with Citrix Metaframe on an NT4 terminal server. The reason is
Citrix only records keystrokes and you are not actually touching the data.
So if the station locks up, you haven't damaged the data, all you lost is
what the users was doing at that moment. Second I use GENDBC to regenerate
the databases and tables and re-copy the data and indexes. After that there
is only a small clean up to do on damaged records. Third, we've implemented
daily backups. Worst comes to worst you only have one day's work to re-coop.
I wouldn't recommend Novell servers, since that is where our problems
started. It seems too dependent on the version of Novell and the client,
whether you data gets corrupted or not.

Hope that helps


Quote:
> x-no-archive:yes

> I looked at a website that claimed using transactions would reduce .dbf
file
> damage.  I am already using buffering, and I don't understand how
transactions
> would further protect the .dbfs.

> Another client of mine did an "end task" on my application after their
workstation
> locked up, and six tables had records whose fields all contained CHR(0)
> characters.  They appear as vertical, narrow black bars, and if the
application is
> run with these records in place, it locks up.  Many of their indexes were
damaged,
> and to top it off, I have run into situations where candidate indexes
break down
> and allow duplicate records.  This is a real ugly mess to clean up.  When
you try
> to do a re-index operation, a uniqueness violation error occurs followed
by the
> total destruction of every index tag beyond the candidate index, as far as
the tag
> order is concerned.

> What I really want to know is how anyone can be expected to make a living
writing
> vfp applications when the slightest malfunction of a workstation trashes
large
> tables containing vital business data and scrambles indexes designed to
enforce
> uniqueness?

> Does anyone have a solid solution to this problem?  I'm seriously ready to
quit
> the vfp business altogether because I can't offer clients a database
programming
> solution that will withstand the flakiness of the Windows environment.

> If anyone knows a consulting company that specializes in bulletproofing
vfp data
> files, please let me know.



Wed, 11 Aug 2004 20:06:01 GMT  
 How do transactions protect against file damage?

Quote:
> Can you use the traditional, "plain" dbf design for your applications, or
do you
> have some kind of ODBC, client/server set up?

Yes, plain DBF. Actually the application is server/server. Both executable
and data on the server. 57 users from all over North America. In the last
four years I have yet to have a crash bad enough to damage any data. Mind
you the Server is equiped with a UPS.

Quote:
> What does a Metaframe cost and what kind of operating system does it use?
How
> much is the NT terminal server software?

You don't really have to use Citrix Metaframe (anymore) with the advent of
Remote Desktop Control (Windows XP), or Terminal Services (Windows 2000
Terminal Server). Citrix Metaframe is very manageable (From an administrator
point of view). It intalls on top of either Windows NT4 Terminal Server (if
still available), or Windows 2000 Terminal Server.
Check out www.Citrix.com for pricing (about $6,000.00 US)
And got to www.Microsoft.com for price on Terminal Server.

Sorry my price would be in Canadian currency anyways.


Quote:
> x-no-archive:yes

> Hi Mike,

> > We
> > choose to go with Citrix Metaframe on an NT4 terminal server. The reason
is
> > Citrix only records keystrokes and you are not actually touching the
data.
> > So if the station locks up, you haven't damaged the data, all you lost
is
> > what the users was doing at that moment.

> Can you use the traditional, "plain" dbf design for your applications, or
do you
> have some kind of ODBC, client/server set up?

> What does a Metaframe cost and what kind of operating system does it use?
How
> much is the NT terminal server software?

> Tom



Thu, 12 Aug 2004 04:08:15 GMT  
 
 [ 3 post ] 

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