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Crystal Reports, ODBC & Access >> ODBC General Issues >> ODBC primer needed
http://www.istechforum.com/YaBB.pl?num=1175016154

Message started by GasGiant on 03/27/07 at 10:22:34

Title: ODBC primer needed
Post by GasGiant on 03/27/07 at 10:22:34

Anytime we rebuild DDF's (including every time we install an update) we lose our ODBC connection on the server. We have a number of applications that use that connection, so the client is on just about every machine. Unfortunately, I'm not savvy enough with the server bit to understand why it dies or how to make it stop or even how to get it restarted once it dies, except to reboot the server.

Anyone else have a better handle on this ODBC thingie?

Title: Re: ODBC primer needed
Post by kevind on 03/27/07 at 12:11:03

Colin,
The ISTECH updates should not update the .DDF files in your Data Folders.
It only updates the .DDF files in the main DBA Folder (DBAMFG, or EVO..(whatever,I don't remember the default!)).

The .DDF files that are used for ODBC access are the ones in the Data (company) folders.
You only need to run ODBCDDF to update them if they fail the Database consistency test in the Pervasive.SQL Control Center.

I only run ODBCDDF if there are inconsistencies listed when running this utility.

To run it, Open Pervasive Control Center, click down to your DBA data database, right click the database name, and select Tasks, then Check Database .... If any database tables have been changed, there will be an inconsistency listed between the current .DDF files and the Table itself.

Another thing to remember is that if you have Views defined in your ODBC DDF files, or Security enabled,
you will have to re-run your SQL script that defines the view and enables security after you run ODBCDDF.
All views and security settings are reset by running ODBCDDF.

BTW: Rebuilding the ODBC DDF files should be done when there are no active connections to the Relational Engine (ODBC).
Running the ODBCDDF.RUN program is kind of like pulling the rug out from under ODBC. It very rudely overwrites the existing .DDF files.

Title: Re: ODBC primer needed
Post by GasGiant on 03/27/07 at 13:46:50

Well, our ODBC connection dies whenever we update Evo, and it dies whenever we rebuild the ODBC DDFs. I guess I just assumed that the two were related, but even if they are not I would still like to restart the ODBC Server driver without rebooting. I guess that rebooting the server after updating Evo is not a big deal, but I like to understand why things happen. It seems like, if it was supposed to happen, that IS Tech would include a step in their updating README that says, "Now you have to restart your ODBC Server."

Title: Re: ODBC primer needed
Post by cathyh on 03/29/07 at 08:04:38

I have never seen this. The only reason I would re-run ODBCDDF is if new files have been created or new fields within files that I can't see until I do.

Title: Re: ODBC primer needed
Post by GasGiant on 03/29/07 at 10:56:36

I suspect that there is something wrong with our ODBC implementation on the server. Where do I go to learn how implementation was supposed to be done?

Title: Re: ODBC primer needed
Post by cathyh on 03/29/07 at 11:38:44

I used the instructions in the following white paper from Midwest Accounting even though it seems out of date- we have a W2000 server and workstations and a few XP Pro workstations, and Pervasive 8. It still has worked for us.
http://www.mwaccounting.com/dba/white_paper.htm

Title: Re: ODBC primer needed
Post by kevind on 03/29/07 at 13:42:04

There is a possibility that the Pervasive Relational Engine on the server is not running.

In Pervasive, the Microkernal Engine handles all the Transactional accesses (DBA Programs) and the
Relational Engine handles all the SQL (ODBC) accesses.

Make sure that the Relational Engine on your Server is running (start->administrative tools->services).
I don't know on Pervasive 8 what the name of the service is. In Pervasive 2000i,
it is called 'Pervasive.SQL 2000(relational)'

Title: Re: ODBC primer needed
Post by GasGiant on 03/30/07 at 09:40:42

Hmmm... so maybe the relational engine dies and won't restart automatically? I'll try restarting that the next time that I have an ODBC glitch.

Title: Re: ODBC primer needed
Post by Lynn_Pantic on 12/12/07 at 07:19:17

Just as an FYI on this thread, nothing in an IS Tech update touches anything related to ODBC. As Kevin and Cathy mention, if we have added data tables that you would like to get to then you need to run ODBCDDF.RUN to get the company specific DDF files for ODBC and also UT-J to generate the master DDFs that Classic Maintain Database uses. Neither of these is automatically called by the update so I should probably update the instructrions to mention it.