network connectivity split database question

  • Thread starter Thread starter Tim Zych
  • Start date Start date
T

Tim Zych

If I use data binding, that is FE controls linked to BE data where the BE is
on a shared drive, what precautions if any must I take w/respect to the
"disconnected" state that the network lapses into after a period of
inactivity?

Has anyone ever noticed this? A simpler example is Explorer. If I open an
instance of Explorer and navigate to shared drives, then walk away for a
couple of hours, come back then try to open a shared drive, it sometimes
takes several seconds for the drives to become available, as if my machine
is reconnecting to the directory structure.

I'm wondering what side effects this can have for a split linked database.
Are there any corruption issues to be aware of? Or is this a non issue?

Thanks.
 
Non-issue, Tim.

You can force Windows to hold the connection open by leaving a recordset
open. You may get a tiny performance boost after a long period of
inactivity, but you also increase the risk of something corrupting.

There are some procedures that do benefit from holding a connection open.
For example, if the back end is moved and you need to loop through your
TableDefs and reassign the Connect property for each, the code runs several
times faster if you OpenDatabase on the back end file first You don't
actually use that Database variable, and you close it as soon as the
relinking completes, but it really makes a difference to hold the file open
for the operation.
 
Thanks Allen.


Allen Browne said:
Non-issue, Tim.

You can force Windows to hold the connection open by leaving a recordset
open. You may get a tiny performance boost after a long period of
inactivity, but you also increase the risk of something corrupting.

There are some procedures that do benefit from holding a connection open.
For example, if the back end is moved and you need to loop through your
TableDefs and reassign the Connect property for each, the code runs several
times faster if you OpenDatabase on the back end file first You don't
actually use that Database variable, and you close it as soon as the
relinking completes, but it really makes a difference to hold the file open
for the operation.

--
Allen Browne - Microsoft MVP. Perth, Western Australia.

Reply to group, rather than allenbrowne at mvps dot org.

BE
Click to expand...
 
Allen Browne said:
Non-issue, Tim.

You can force Windows to hold the connection open by leaving a recordset
open. You may get a tiny performance boost after a long period of
inactivity, but you also increase the risk of something corrupting.

There are some procedures that do benefit from holding a connection open.
For example, if the back end is moved and you need to loop through your
TableDefs and reassign the Connect property for each, the code runs several
times faster if you OpenDatabase on the back end file first You don't
actually use that Database variable, and you close it as soon as the
relinking completes, but it really makes a difference to hold the file open
for the operation.

--
Allen Browne - Microsoft MVP. Perth, Western Australia.

Reply to group, rather than allenbrowne at mvps dot org.

BE
Click to expand...
 
Tim Zych said:
If I use data binding, that is FE controls linked to BE data where the BE is
on a shared drive, what precautions if any must I take w/respect to the
"disconnected" state that the network lapses into after a period of
inactivity?

Has anyone ever noticed this? A simpler example is Explorer. If I open an
instance of Explorer and navigate to shared drives, then walk away for a
couple of hours, come back then try to open a shared drive, it sometimes
takes several seconds for the drives to become available, as if my machine
is reconnecting to the directory structure.
Click to expand...

What I've noticed is that Access 97/Jet 3.5 transmits about 2.5 kb of
data every 30 seconds or so across the network when using a network
monitor. Thus I suspect this is sufficient to keep this network
connection from timing out as happens with Explorer. I don't know if
A2000 does the same.
I'm wondering what side effects this can have for a split linked database.
Are there any corruption issues to be aware of? Or is this a non issue?
Click to expand...

Corruption issues seem to happen only when doing updates and only
during that brief moment when the update is actually happening. Which
is not the same as updating a record on a form with the pencil in
place. One client has had five or ten power failures where all 10 or
20 users were affected without any corruption issues.

Tony
--
Tony Toews, Microsoft Access MVP
Please respond only in the newsgroups so that others can
read the entire thread of messages.
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm
 
If the network or PC goes down while the file is being held open, there is a
risk of corruption. In a stable environment, this may be a small enough
factor that you choose to ignore it, but my preference is not to hold things
open any longer than necessary.

Depends on your values: which is more important: data integrity above
performance?

--
Allen Browne - Microsoft MVP. Perth, Western Australia.

Reply to group, rather than allenbrowne at mvps dot org.

Fred Boer said:
Dear Allen and Tony:

How does this relate to the LBD locking issue as described here:
http://www.granite.ab.ca/access/performanceldblocking.htm

I have implemented this for my application, but, Allen, your answer seems to
suggest that this increases the risk of corruption? Or am I confused?

Thanks!
Fred Boer
Click to expand...
issue?
 
Fred Boer said:
How does this relate to the LBD locking issue as described here:
http://www.granite.ab.ca/access/performanceldblocking.htm

I have implemented this for my application, but, Allen, your answer seems to
suggest that this increases the risk of corruption? Or am I confused?
Click to expand...

Now here I disagree with Allen. If the connection was doing updates
then yes it would raise the risk of corruption. But if it's just
sitting there doing nothing then I don't see how the risk of
corruptions can increase.

With the possible exception of bad data being injected into the
network by unstable hardware or such.

Tony
--
Tony Toews, Microsoft Access MVP
Please respond only in the newsgroups so that others can
read the entire thread of messages.
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm
 
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