[egenix-users] cursor.executedirect configurable?

[M.-A. Lemburg]

Hello Brad,

On 2008-09-10 04:18, Brad Allen wrote:
> I am using mxODBC 3 with the Storm ORM, which makes use of
> cursor.execute. I would like to find a way to configure mxODBC to use
> executedirect without having to change or override Storm's call to
> cursor.execute.
> 
> Is there some way to configure mxODBC to use the executedirect behavior
> when cursor.execute is called?

No, that's not possible without wrapping the cursor object and
then redirecting the method in the wrapper.

Note that cursor.execute() will work like cursor.executedirect()
when called without parameters.

You should check the performance of using one over the other.
cursor.executedirect() will bypass the prepare step, so the
statement will have to be parsed and processed over and over
again.

Some database backends do clever caching on the server, so this
is not an issue, in fact, it's faster for simple queries since
you avoid a few network round-trips.

For other backends, it's slower, since they don't implement
such caching.

Another issue is related to parameter binding: using
cursor.executedirect() the ODBC driver does not have any
parameter type information available (this only becomes
available via the prepare step), so mxODBC cannot do
any efficient conversion to database data types on the
client side. This may result in conversion problems on
the server side and introduce extra overhead.

-- 
Marc-Andre Lemburg
eGenix.com

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