Re: issues with SQL size st.execute(SQL) in 8.3.3

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От Achilleas Mantzios
Тема Re: issues with SQL size st.execute(SQL) in 8.3.3
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Msg-id 200810182224.35872.achill@matrix.gatewaynet.com
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Ответ на Re: issues with SQL size st.execute(SQL) in 8.3.3  (Kris Jurka <books@ejurka.com>)
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Στις Saturday 18 October 2008 16:48:12 ο/η Kris Jurka έγραψε:
>
> On Sat, 18 Oct 2008, Achilleas Mantzios wrote:
>
> > Στις Friday 17 October 2008 20:34:57 ο/η Kris Jurka έγραψε:
> >>
> >> It all depends on whether you are relying on any V3 features in other
> >> places.  I have a fix for the issue (attached).  I'm still testing it and
> >> will hopefully apply it this weekend.
> >
> > Regarding V2, its just a simple program like the one i showed,
> > can you point some cases which would explicitly rely on V3 features ?
> > Which JDBC method calls would be affected by the enforcement of V2?
> > Can the rest of the backends (other than the one serving the v2 client) be
> > affected in any way by this?
>
> If it's just this connection, then switching to V2 is a fine solution.  A
> simple execute works fine and won't affect anything else.  I thought you
> were considering switching your whole application to V2 which needs a
> little more thought.  As an example ParameterMetaData is only
> implementable with the V3 protocol.
>
> I have applied to previous patch to CVS, and it should fix your problem,
> but it does not solve every deadlock situation.  The deadlock avoidance
> code was originally written for batch execution which should not be
> returning ResultSets.  If many long queries that return significant
> results are issued with a single execute we will still deadlock.  Solving
> this would require tracking the bytes actually sent rather than the number
> of queries sent, or a more significant redesign to use multiple threads or
> NIO.  Attached is sample code which still deadlocks.

Kris,
many thanx for the explanation of the problem and the patch.

>
> Kris Jurka



--
Achilleas Mantzios

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