Re: (ITS#7638) Handle connection loss in SQL backend

[pierre@reactos.org]

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Unfortunately, I don't see any other solution. I browsed everything I=20
could in ODBC doc, in order to be able to query link status, but there's =

no way.

And the other solution to redo the whole statement in case of failure=20
would be even more complex and would require too many code rewrites due=20
to a complete logic change. So, it seems to me to be the intermediate=20
solution.

The overhead being limited on "decent" connection.

Regards,

On 07/07/2013 14:33, Michael Str=F6der wrote:
> pierre@reactos.org wrote:
>> With this patch, before preparing any req on the given connection=20
>> handle, the
>> backend will first try to check whether the connection is active by=20
>> issue a
>> dummy query. In case it's not, it will close the previous connection=20
>> and open a
>> new one. And then, will prepare the req on the connection link.
>>
>> I made this choice of developement because, preparing statement,=20
>> executing it
>> and then, only looking whether it fails to re-submit would have been=20
>> more
>> complex, since it would have required to start over the whole process =

>> for the
>> query (statement preparation and such) while preparation & execution=20
>> aren't not
>> in the same function.
>
> Hmm, so there's an extra dummy query for each real query. If the SQL=20
> DB is connected over network this means a synchronous extra round trip =

> for each query.
>
> Ciao, Michael.
>
>


--=20
Pierre Schweitzer<pierre at reactos.org>
System Administrator
ReactOS Foundation



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