Hi

Further to my last email. I have just run the code again with these
results


Oldest transaction 441772
Oldest active 441773
Oldest snapshot 441773
Next transaction 456774


I note that in my first email the 'Oldest transaction' had caught up
with 'Next transaction'. It hasn't in the above and in most of my tests
the results are as above not below. Weird!

Thanks
Rob

On 27/03/2014 9:33 a.m., Robert Martin wrote:
> Hi
>
> I have been playing with a test app that uses auto commit. Basically
> there are 3 components and IBODatabase and two IBOQuery components. One
> of these is an insert Query and the other a select query. I am using
> the latest FB 2.5.2 in superclassic mode. My IBODatabase is using all
> defaults.
>
> I do a gstat on the DB and confirm that the OAT and Next transaction are
> close (i.e. 1 different) then click run. The system inserts 15000
> (although the effects are similar when 30000 inserts are used) entries
> and I run GStat again. The result is shown below.
>
> Oldest transaction 426761
> Oldest active 411761
> Oldest snapshot 411761
> Next transaction 426762
>
> If I close the app the above remain constant. If I reopen the app and
> run the select Query the numbers all 'reset'.
>
> I assumed that connecting triggers garbage collection. So to test this
> I re ran and instead of opening the app and running the select I
> manually ran a -sweep using gfix.exe. Surprisingly this doesn't 'reset'
> the transactions. Any ideas what is going on here?
>
>
> The results above are the same even when I attempt to 'force' a hard
> commit by doing an explicit IBODatabase.IB_Transaction.StartTransaction
> and IBODatabase.IB_Transaction.Commit after the insert loop. This is
> not what I would have expected.
>
> What am I doing wrong ?
>
> p.s. If I explicitly start and commit transactions around the inserts
> the OAT stays close to the Next Transaction. So that seems to be
> working fine.
>
> Here is my test code if that helps...
>
> var
> Counter : Integer;
> begin
> StopButton.Enabled := True;
> RunButton.Enabled := False;
>
> try
> ConnectToDB;
>
> ProgressBar.Position := 0;
> ProgressBar.Max := StrToInt(RunEdit.Text); //Normally 15000
>
> fStopNow := False;
> Counter := 0;
> while (Counter < ProgressBar.Max)
> and (fStopNow = False) do begin
> // InsertQuery.IB_Transaction.StartTransaction;
> InsertQuery.ExecSQL;
> // InsertQuery.IB_Transaction.Commit;
> ProgressBar.Position := ProgressBar.Position + 1;
> Inc(Counter);
>
> Application.ProcessMessages;
> end;
>
> //Attempt to explicity force CommitRetaining transaction to
> 'hard' commit
> IBODatabase.IB_Transaction.StartTransaction;
> IBODatabase.IB_Transaction.Commit;
>
> finally
> ProgressBar.Position := 0;
>
> StopButton.Enabled := False;
> RunButton.Enabled := True;
>
> // IBODatabase.Disconnect;
> end;
>
>
>
> Thanks
> Rob
>
>
>