[dba-VB] Unspecified Error

I've never programmed against an MDB.

Are you opening and closing the connection repeatedly?  I did have an issue where I was "leaking" 
connections (kinda) and ran out of connections to SQL Server.  Basically the garbage collector runs 
when it thinks it needs to.  If you don't force a cleanup of non-native (to .Net) objects such as 
SQL Server connections, then the GC doesn't know it needs to clean up and doesn't do so.  I had to 
build a dispose method for my classes and intentionally call that dispose method as the class was 
closed, which forced the GC to release the non-native objects immediately instead of whenever it 
decided to.

John W. Colby
www.ColbyConsulting.com

On 10/29/2010 5:05 AM, Shamil Salakhetdinov wrote:
> Hi All --
>
> After several hours (~6 hours Win7 64bit, ~24hours WinXP) of running
> multi-threaded (.NET Framework 3.5 SP1 WinForms) desktop application using
> .mdb files as backend I'm getting the following runtime error:
>
> Exception ->  Unspecified error
>
> StackTrace ->     at
> System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString
> constr, OleDbConnection connection)
>     at
> System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOption
> s options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection
> owningObject)
>     at
> System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbCon
> nection owningConnection, DbConnectionPoolGroup poolGroup)
>     at
> System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection
> owningConnection)
>     at
> System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection
> outerConnection, DbConnectionFactory connectionFactory)
>     at System.Data.OleDb.OleDbConnection.Open()
>     at
> NetworkManager.SearchInputFileHandler.GetInputRows(SearchProgramTypeEnumerat
> ion programType, Int32 startRowNum, Int32 rowsQty, Boolean setupInProgress,
> Boolean filterOutUninitializedRows)
> 	
> It looks like this is an OleDbProvider bug.
>
> Have you seen/experienced something like that?
>
> Context:
>
> 1. I do exclusively use
>
> using (OleDbConnection cnn = new
> OleDbConnection("{{mymdbConnectionStringHere}}"))
> {
>      cnn.Open();
>      ...
> }
>
> 2. I do use IN clause in some select SQL expressions to point to external
> MDB tables.
>
> I guess the issues is caused by case (2). Although that's still a hypothesis
> here to check (some code fixes are needed in the core code of my
> application, and I'm considreing now will that be worth fixing, or I should
> better switch to MS SQL backend.)
>
> Thank you.
>
> --
> Shamil
>
>
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