Re: ODBC Driver Failure- MS Access- Large record volume

I hope using the driver version Dave P. suggests solves your problem.

It sounds difficult to troubleshoot. I would say use care when turning logging on at the server. Not so 
much because of resources, but you need to configure PostgreSQL for what you want to log. That is edit the 
postgresql.conf file. Note the log_statement parameter. You could start with just logging connections to 
see if any fail. It seems like it would be difficult to log millions of transactions to find one error. 
That's a hec of log file to look through. And turning on ODBC logging (client side via the ODBC 
Administrator) could (would) be even more taxing.
I would expect that ODBC Direct or INSERTS in general to provide much better perfromance than using DAO 
for AddNew.
In general, the thing you want is as much information as possible when an error is thrown. I haven't used 
ODCBDirect extensively so I am not sure about the best way to determine if PostgreSQL server threw  a 
native error, or Access, or some "container" is throwing the error. With your "ODBC Call failed", it would 
be nice to know if there are err.Number, err.Source, and to know if the ODBCDirect Workspace contains an 
actual collection of errors instead of just one.
Some others might know if ADO provides a better object model for what you are 
trying to do.

Also note basic observations, like do failures happen at the beginning or in the middle of processing 
thousands or transaction? Is Access constantly open or does it get opened afresh periodically? Do you 
process data in sessions (one now and again later). How far apart are the sessions. Is there a patterm 
relative to the failures?




Robin Weber wrote:
> Hi Greg,
>
> Thanks so much for your response.  It's nice to get a dialog going.  To 
> answer your questions:
> > 1. What version of the ODBC driver are you using? (I found my  version 
> > using REGEDIT to key
> > HKEY_CURRENT_USER\Software\Microsoft\Installer\Products)
> 08.00.0102
> I had the same problem running a couple of different versions in the 7.0 
> series.
> > 2. What version of Access are you using?
> MS Access 2003 SP1
>
> > 3. What Access library are you using -DAO or ADO?
> Usually DAO, but I've had the same problem using ODBCDirect, repeatedly 
> executing SQL lines (such as inserts) several million times.
> > 4. Since Access is typically interactive, how are you transacting 
> > these millions of records, reading a file or is some external device 
> > driving Access?
> I'm reading text files, parsing the lines, loading variables, and either 
> processing AddNew's on a linked table, or doing Inserts in an ODBCDirect 
> workspace
> > 5. Are you connecting though the Access objects (normal queries and 
> > tables), or using pass-through?
> Both, as above.
>
> > 6. What version of Postgres server are you using? Linux or Windows?
> 8.0.3 under Windows XP, unfortunately.  (Our lab is Linux-deficient)
>
> > 7. Is logging turned on at the server? (e.g. pg_ctl start -l my_pg.log)
> Not yet.  I will activate it.  Can you give me a hint on what to look 
> for in the log?
> I will experiment with getting a hold of the connection object and 
> closing and opening it to start a new driver instance.  It takes a long 
> time of stuffing data through the driver to re-create the crash, so it's 
> hard to know when I've gotten around the bug or not.
> Please let me know if my answers invite any new information.
>
> Oh, also, the link from the Postgres web site has changed, and I'm not 
> sure where to get new versions of the driver.  Any help with my confusion?
> With thanks,
> Robin
>
> At 02:29 PM 9/8/2005, you wrote:
>
> > Hello and welcome Robin,
> > I find the key to getting help is giving enough information.
> >
> > You might answer a few questions.
> > 1. What version of the ODBC driver are you using? (I found my  version 
> > using REGEDIT to key 
> > HKEY_CURRENT_USER\Software\Microsoft\Installer\Products)
> > 2. What version of Access are you using?
> > 3. What Access library are you using -DAO or ADO?
> > 4. Since Access is typically interactive, how are you transacting 
> > these millions of records, reading a file or is some external device 
> > driving Access?
> > 5. Are you connecting though the Access objects (normal queries and 
> > tables), or using pass-through?
> > 6. What version of Postgres server are you using? Linux or Windows?
> > 7. Is logging turned on at the server? (e.g. pg_ctl start -l my_pg.log)
> >
> >
> > By the way other list memebers, after installation is there a 
> > recommended way to determine the pgODBC driver version?
> > Robin,
> > Before knowing any of these answers I can say
> > the  ADO Connection object is your means of "opening and closing" the 
> > ODBC (or OLE/DB) driver. Open and close often is the rule of thumb for 
> > interacting with server database. There is typically caching going on 
> > for recent connections, so the opening a new connection is not the 
> > resource hog it might seem. If all that is ok, you may indeed have a 
> > pgODBC  driver version with a leak.
> > And as a complete aside because it has bitten me too many times, set 
> > the Jet ConnectionTimeout under
> > HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\Jet 4.0\ to 0 
> > (never timeout). A jet connection (linked table) will loose 
> > connectivity after a default time of 60 minutes of inactivity unless 
> > this key is set to some other value (longer or shorter) or 0.
> > Refreshing linked tables is also do-able. You should be able to google 
> > it or write back and someone will no doubt expound upon it. The Access 
> > (version) Handbook's from Sybex are excellent references for the 
> > mundane to the arcane.
> >
> > Robin Weber wrote:
> >
> > > Hello Community,
> > > I'm new to this list.
> > > I am a user of the Postgres ODBC driver, mainly under MS Access and 
> > > Matlab.  We deal in very large tabular datasets.  (My largest table 
> > > is currently 72 million records, and it will grow several times that 
> > > size before the year is out.
> > > The driver fails after several million record inserts (under access).
> > > Once failed (with nothing more helpful tan an "ODBC call failed" 
> > > message box), it will process no further requests.  (I believe it 
> > > will also fail after receiving that much data, as well a sending.)
> > > (I would think of a memory leak of some sort, but in my 27 pro years 
> > > of programming, I have never dealt with the inner workings of an ODBC 
> > > driver, and I don't know how to get driver error information.  This 
> > > is also my first open source experience, so please forgive my naivete.)
> > > I would like to figure out how to fix this problem.  I'm willing to 
> > > help debug, but I need help getting started.  How do I go about 
> > > trying to understand this problem?
> > > One thing that might be helpful:  Is there a programmatic way to get 
> > > Access to close and unload, then reopen the ODBC driver without 
> > > actually quitting Access?  I notice that when I start Access "fresh" 
> > > I can pump another several million records through before failing.  
> > > If I can make my programs unload then reload the driver every few 
> > > million records, it might make a good workaround for my problem.  Any 
> > > clues out there?
> > > With thanks,
> > > Robin
> > >
> > > --------------------------------------------------
> > > Robin Weber
> > > Data Manager and Application Developer for
> > > Marine Mammals and Birds
> > > Tagging of Pacific Pelagics Project
> > > University of California Santa Cruz
> > > Long Marine Lab - Center for Ocean Health
> > > 100 Shaffer Road
> > > Santa Cruz, CA 95060-5730
> > > (831) 459-2691
> > >
> > >
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> --------------------------------------------------
> Robin Weber
> Data Manager and Application Developer for
> Marine Mammals and Birds
> Tagging of Pacific Pelagics Project
> University of California Santa Cruz
> Long Marine Lab - Center for Ocean Health
> 100 Shaffer Road
> Santa Cruz, CA 95060-5730
> (831) 459-2691
>
>
>
>
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