Re: [cx-oracle-users] prepare not needed before execute many, right?

[Mark H. <mh...@pi...>]

Amaury Forgeot d'Arc wrote:
> 2007/1/18, Mark Harrison <mh...@pi...>:
>> Is there a difference between calling:
>>
>>      curs.prepare("call set_x1(:a,:b)")
>>      curs.executemany("call set_x1(:a,:b)", mylist)
>>
>> and just:
>>
>>      curs.executemany("call set_x1(:a,:b)", mylist)
>>
>> I know it doesn't make sense, but my test program
>> seems to be faster with the prepare.  I'm sure it's
>> other factors, but I just want to make sure I'm
>> not being stupid.
>>
> 
> I checked with the cx_Oracle source code, and you seem to be right:
> at the C level, there is no difference between the two cases.
> Moreover, the additional function call should make the first sample a
> little slower.
> 
> BTW, when the statement is prepared, it's better to call executemany
> with None instead of repeating the query:
>     cursor.executemany(None, mylist)
> cx_Oracle compare queries by string identity ('is', not '=='). Here
> the compiler optimizes the script by sharing the same string for the
> two lines. So it should not have any performance impact in this case.

Good advice, Thanks!
Mark