Subject Re: [IBO] Integer Overflow Exception - TIB_StoredProc
Author G. Nau
then I'll drop the IB_StoredProcs and give it a try with ib_cursor.
The effective procedure I'm using in my application is given a
stringlist with partnumbers and will return the PK of the first one
the SP which simply returns "1" was just to verify it's not the SP itself
giving the overflow and can replicate the overflow in a small test


Am 7 Sep 2005 um 19:18 hat Helen Borrie geschrieben:

> At 10:31 AM 7/09/2005 +0200, you wrote:
> >Hellen,
> >it is indeed an integer overflow and not a GDSCode.
> >The overflow happens in the IB_storedproc.execute method.
> TIB_Dataset.SysClose (in my version 4.5Ai of IBO)
> >---
> > try
> > Inc( FCursorGen ); <<<<-- here
> > except
> > FCursorGen := 0;
> > end;
> >---
> >FcursorGen is defined as word and overflowing at a count of 65535
> >(which happens approx. after calling TIB_Storedproc.execute 32768
> >times).
> Still, I think it will be signed, so WORD (being a 4-byte integer) will
> overflow at 32768.
> >Is this a limitation within FB or do I have to do some cleanup work
> >after a call to TIB_storedproc.execute to keep the value of the
> >FCursorGen low?
> I don't know the answer but I would suppose that Jason limits it
> deliberately for a specific reason, e.g. to lower the bar for excessive
> concurrent executions, or something of that ilk.
> Hopefully Jason will step in and explain his exact rationale.
> >To give it a test I redefined the FcursorGen from Word to LongWord
> >and can call TIB_storedproc now without any limit.
> >But this doesn't sound like a correct solution to me.
> >What has to be done to keep the FCursorGen counter at low
> >numbers?
> In real life, you wouldn't have a SP like your example. Why wouldn't you
> just write a client function to calculate something that always produced
> the same result (or an algorithmic result)? SPs are meant to act on data,
> within the context of a transaction.
> It's very uncool, for example, to iterate through 30,000 records on the
> client side and feed through 30,000 SP calls - presumably parameterised to
> be at all useful - without batching them into realistic chunks. If a
> developer absolutely insists on designing an application this way, then
> 8000 record changes is the recommended maximum per transaction.
> If (as your sample SP suggests) your aim is to return a set from the SP,
> then you would not have multiple SP calls in a transaction: only one.
> A further tip: stay clear of TIB_StoredProc. It's only there for
> compatibility. IBO has much better ways to use SPs - ib_query or ib_cursor
> for selectable procedures, ib_dsql for executable ones.
> Helen

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