Hi Aleksey,
I known this ( with FOPEN ) i can control the total number of file handles used by VFP.
But this behaviour for the USE with UPDATE it does not have some sense for me.
My Comment:
> Visual FoxPro does use one file descriptor for a table across all work areas and data sessions.
This is good for performance
( USE AGAIN a open table is 6x faster on local, and 7-10x faster on remote tables )
and necessary for simplified table cache management on VFP engine.
> The very first USE opens a file with read-only attribute if NOUPDATE is used.
This is not good, NOUPDATE but marks the cursor read-only, and to not touching the
read-only attribute from the file descriptor.
Another possible Clause FILEREADONLY ( for set the read-only attribute from the file descriptor) he is not possible because it destroy the principle of isolation of the datasession.
The only way is to put a read-only attribute, for the table, on DBC dictionary.
> USE ... AGAIN (without NOUPDATE) inherits read-only attribute from the file descriptor.
Not good on a developer environment.
> USE ... AGAIN NOUPDATE doesn't change read-only attribute for the file descriptor, but marks the cursor read-only.
This is what it must make
> The first USE in a data session removes read-only attribute from the file descriptor unless NOUPDATE is used,
This destroy the isolation between the datasession. A bug for me.
>but it doesn't remove read-only attributes from any existing cursor.
It would be a disaster if it made it.
Thanks
Fabio
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