>Attila Ambrozai
>Hungary
>am...@ambro.hu

>  Source := TFileStream.Create(DirInfo.Name, fmOpenRead OR
FMSHAREDENYNONE);

> please note FmShareDenyNode flag
> --
> Roman

> >I want my program to make backup copies of all the Paradox
> >tables (for all of them CachedUpdates is true!) it uses. But as
> >soon as it reaches the linecontaining
> >"Source := TFileStream.Create(DirInfo.Name, fmOpenRead);"
> >an error message pops us saying "table1.xg0 can't be opened"
> >(that's the first file). So somewhy it can't open the files of the
> >tables. Why??? In BDE setting LocalShare is True, the
> >Exclusive property is turned false for all tables. If I try to unlock
> >the table I receive another error message saying "Table not
> >locked". So they are not exclusive, not locked, but shared, then
> >why can't I copy the files of tables? Plese help, this is urgent.
> >Another thing. I noticed files named "pdoxusrs.lck" in both the
> >program and bote the database directory. What is that used for?
> >And sometimes I also notice "paradox.lck" in both directories
> >mentioned above but sometimes don't. What is the reason of
> >that? Thank you in advance.

> >Attila Ambrozai
> >Hungary
> >am...@ambro.hu

> I want my program to make backup copies of all the Paradox
> tables (for all of them CachedUpdates is true!) it uses. But as
> soon as it reaches the linecontaining

> Is the database in use when you copy the files?
> I am not asking because that might lock the tables, I am asking
> because you can't reliably make a backup copy of a Paradox database
> using simple file copying when the database is in use.
> There is a good chance that your backup has logical data corruption.

> Thank you very much for the help. It works now. I would like to
> ask another question. I also want to restore the backupped
> tables. So, because I can't overwrite table files wich are currently
> in use, I did this:
> MyTable.Close;
> MyTable.DeleteTable; This point I always receive an error
> message "Table is busy". Why? Maybe because cahced updates?
> (But no transaction is started at that time of course). Please help
> me if you know the reason. Or do you have any better idea how
> to restore the backupped tables? Thanks.

> If you perform a file copy in the middle of such a series
> of steps, your copied files may have internal inconsistencies
> as well as the different files may not be consistent with each other.
> an "Index Out of Date" error can easily happen.
> The probability depends on the level of activity, of course.

> We have solved this problem using Vinca's snapshot server in combination
> with specific settings for the network clients (turning cached writes off,
etc.).
> The snapshot server waits for a predefined period of disk inactivity -
which
> ensures that no write operations are under way and all buffers are
flushed,
> and then performs a "snapshot" - which is like an instant backup.

> Thanks for the answer again.
> And what if I close all tables before making the copy? On the
> other hand I setted local share to true in BDE setting so all
> the changes goes promptly physically into the tables. I think
> this two things together should provide secure conditions to
> save te files. What do you think? (The program will run only
> a single computer. Cached updates and local share are both
> turned on to force prompt writing and reducing file access
> to reduce the chance of data loss if Windows frozes or if
> a power shortcut occurs.)

> If the database is on the network, you will need to
> ensure that your network client does not cache writes.
> What to do depends on the client. Just search this newsgroup,
> there have been a couple of related posts lately.