Icon View Thread

The following is the text of the current message along with any replies.
Messages 1 to 9 of 9 total
Thread Slow opening
Mon, Nov 12 2007 9:22 AMPermanent Link

"Ronald"
Hi,

I have an app. with approximately 15 tables (version 3.x). If the first
users opens the application all the tables open fast, but a seconde user has
two wait for more hen 5 minutes before all tables are opened. Whact could be
the problem? All other applications that I create with dbisam work very fast
(the have less tables).

Greetings,
Ronald
Mon, Nov 12 2007 10:19 AMPermanent Link

Arnd Baranowski
Ronald,

had a similar effect on version 3.x on a customer site long time ago and
it was a virus scanner who was reponsible for this effect.

Arnd

Ronald wrote:
> Hi,
>
> I have an app. with approximately 15 tables (version 3.x). If the first
> users opens the application all the tables open fast, but a seconde user
> has two wait for more hen 5 minutes before all tables are opened. Whact
> could be the problem? All other applications that I create with dbisam
> work very fast (the have less tables).
>
> Greetings,
> Ronald
Mon, Nov 12 2007 10:29 AMPermanent Link

"Robert"

"Ronald" <rvdpas@gmail.com_removethis> wrote in message
news:772EF956-4666-4164-9F5B-5E3637E0AF4F@news.elevatesoft.com...
> Hi,
>
> I have an app. with approximately 15 tables (version 3.x). If the first
> users opens the application all the tables open fast, but a seconde user
> has two wait for more hen 5 minutes before all tables are opened. Whact
> could be the problem? All other applications that I create with dbisam
> work very fast (the have less tables).
>

Could be a number of things. Obviously related to locks, since it only
happens with more than one user. The fact that your other DBISAM apps run OK
more or less rules out antivirus or such things as the possible culprint.
Has to be something in your code.

I would start by logging to a text file the time stamp when you open each
table, that will let you zero in on the problem table(s).

Do you use pessimistic locking? Does this happen ALL the time, that is all
terminal 1 has to do is open the tables to consistently cause terminal 2 to
take 5 minutes, or do you have to have some activity on terminal 1? Do you
get the same effect if you reverse the sequence, open terminal 2 then open
terminal 1?

Robert


Mon, Nov 12 2007 11:03 AMPermanent Link

"Chris Thornton"
"Robert" <ngsemail2005withoutthis@yahoo.com.ar> wrote in message
news:DE665189-DEE7-4AF9-
> Do you use pessimistic locking? Does this happen ALL the time, that is all
> terminal 1 has to do is open the tables to consistently cause terminal 2
> to take 5 minutes, or do you have to have some activity on terminal 1?

Along those lines, I'd try opening the tables on terminal 1 with DBSys and
see if that has the same effect as opening them with the app.
Mon, Nov 12 2007 5:37 PMPermanent Link

Tim Young [Elevate Software]

Elevate Software, Inc.

Avatar

Email timyoung@elevatesoft.com

Ronald,

<< I have an app. with approximately 15 tables (version 3.x). If the first
users opens the application all the tables open fast, but a seconde user has
two wait for more hen 5 minutes before all tables are opened. Whact could be
the problem? All other applications that I create with dbisam work very fast
(the have less tables). >>

See this thread for more information:

http://www.elevatesoft.com/scripts/newsgrp.dll?action=openmsg&group=5&msg=58847&page=1#msg58847

More than likely you are simply seeing the effects of opportunistic locking.
The second application instance will be much more sensitive to the network
performance than the first, so it may simply be exposing the fact that data
is actually travelling over the network in the second instance.

--
Tim Young
Elevate Software
www.elevatesoft.com

Mon, Nov 12 2007 5:39 PMPermanent Link

"Robert"

"Tim Young [Elevate Software]" <timyoung@elevatesoft.com> wrote in message
news:3B5BAED1-59A7-4F34-8461-BBA5357A268C@news.elevatesoft.com...
> Ronald,
>
> << I have an app. with approximately 15 tables (version 3.x). If the first
> users opens the application all the tables open fast, but a seconde user
> has two wait for more hen 5 minutes before all tables are opened. Whact
> could be the problem? All other applications that I create with dbisam
> work very fast (the have less tables). >>
>
> See this thread for more information:
>
> http://www.elevatesoft.com/scripts/newsgrp.dll?action=openmsg&group=5&msg=58847&page=1#msg58847
>
> More than likely you are simply seeing the effects of opportunistic
> locking. The second application instance will be much more sensitive to
> the network performance than the first, so it may simply be exposing the
> fact that data is actually travelling over the network in the second
> instance.
>

Hmmm, 5 minutes to open a few tables? No way. And he does not see this
behavior with other DBISAM applications.

Robert

> --
> Tim Young
> Elevate Software
> www.elevatesoft.com
>

Tue, Nov 13 2007 8:55 PMPermanent Link

Tim Young [Elevate Software]

Elevate Software, Inc.

Avatar

Email timyoung@elevatesoft.com

Robert,

<< Hmmm, 5 minutes to open a few tables? No way. And he does not see this
behavior with other DBISAM  applications. >>

If he has a ton of lookups, filters, etc. that are causing a lot of network
activity, then it certainly would be possible for opportunistic locking to
cause the time to explode once it actually had to go over the wire.
However, you're probably right in that there's most likely a combination of
things at work here, of which the oplocks is just one issue.

--
Tim Young
Elevate Software
www.elevatesoft.com

Sun, Nov 25 2007 12:51 PMPermanent Link

"Ronald"
I have found the problem. It wasn't the virusscanner. I used a temp table
which itself used a lookuptable. BecauseI frequently searched in that table
things slowed down especially with the second user.
But the main solution was in a master-detail realtion. I first opened the
detail and then the master. Turning that around for three tables made the
biggest diiference.
Thanks for all the answers.

"Ronald" <rvdpas@gmail.com_removethis> schreef in bericht
news:772EF956-4666-4164-9F5B-5E3637E0AF4F@news.elevatesoft.com...
> Hi,
>
> I have an app. with approximately 15 tables (version 3.x). If the first
> users opens the application all the tables open fast, but a seconde user
> has two wait for more hen 5 minutes before all tables are opened. Whact
> could be the problem? All other applications that I create with dbisam
> work very fast (the have less tables).
>
> Greetings,
> Ronald
Mon, Nov 26 2007 4:54 PMPermanent Link

Tim Young [Elevate Software]

Elevate Software, Inc.

Avatar

Email timyoung@elevatesoft.com

Ronald,

<< I have found the problem. It wasn't the virusscanner. I used a temp table
which itself used a lookuptable. BecauseI frequently searched in that table
things slowed down especially with the second user.  But the main solution
was in a master-detail realtion. I first opened the detail and then the
master. Turning that around for three tables made the
biggest diiference. >>

I'm glad that you found the problem.  Lookups and calculated fields can be
insidious at times because they can really kill performance in a very
unobvious way. Smiley

--
Tim Young
Elevate Software
www.elevatesoft.com

Image