I believe setting unidirectional to True is where you are getting problems.

Here's a rule of thumb: If your query is ever going to need to buffer more
than one record at a time, DO NOT USE UNIDIRECTIONAL.

If unidirectional is true it means you are totally in control of the query
and the automatic features of IBO handling the OAT advancement are
potentially intrusive and therefore benign.

Jason Wharton

> -----Original Message-----
> From: IBObjects@yahoogroups.com [mailto:IBObjects@yahoogroups.com]On
> Behalf Of Stephen Boyd
> Sent: Wednesday, November 02, 2005 8:38 AM
> To: IBObjects@yahoogroups.com
> Subject: [IBO] CommitAction and automatic AOT advancement
>
>
> I am trying very hard to understand the relationship between
> CommitAction and automatic OAT advancement. I thought I had it
> figured out but I have come across a situation where it doesn't work
> the way I thought it did. I am using TIBOQuery with TIB_Connection
> and TIB_Transactions components.
>
> The strategy that I have adopted is to set CommitAction to caClose for
> all queries that are used to look up values and to set CommitAction to
> caFetchAll for all queries that drive DBGrids. Lookup queries have
> Unidirectional set to True. I have set the TimeoutProps as follows:
>
> AllowCheckOAT = 10
> Attempt = 5
> AttemptMaxRow = 1000
> AttemptRetry = 1
> AttemptTicks = 250
>
> In most situations this appears to work the way I expect. That is
> caClose queries are close, caFetchAll queries are fetched to EOF and
> the transaction is commited. But I have 1 query where this doesn't
> seem to work so I started digging around with the debugger and
> discovered that queries with Unidirectional = True and do not get
> forced closed. In TIB_Transaction.SysTimeoutAttempt we have the
> following code:
>
> CanAttemptCommit := true;
> for ii := 0 to DatasetCount - 1 do
> with Datasets[ ii ] do
> begin
> if CursorIsOpen then
> ---------------->
> if Unidirectional or Fetching {or ( BufferRowCount > 1000 )}
> then
> begin
> CanAttemptCommit := false;
> Break;
> end
> <-----------------
> CanAttemptCommit := true;
> for ii := 0 to DatasetCount - 1 do
> with Datasets[ ii ] do
> begin
> if CursorIsOpen then
> if Unidirectional or Fetching {or ( BufferRowCount > 1000 )}
> then
> begin
> CanAttemptCommit := false;
> Break;
> end
>
> Why do Unidirectional queries not get forced closed? If CommitAction =
> caClose then isn't that an indication that I don't care about the
> content of this query? What do I have to do the get the OAT to
> advance in this situation?