Re: [cx-oracle-users] Performance of objects

[Walter <wa...@li...>]

On 4 Sep 2017, at 23:21, Anthony Tuininga wrote:

> On Wed, Aug 30, 2017 at 3:40 AM, Walter Dörwald 
> <wa...@li...>
> wrote:
>
>> On 30 Aug 2017, at 1:09, Anthony Tuininga wrote:
>>
>>> Hi Walter,
>>>
>>> I just tried this on Linux with 12.2 Client and Database. I got 
>>> these
>>> results:
>>>
>>> table 1.1217586994171143
>>> object 0.8592920303344727
>>>
>>> When I change the number of iterations from 1300 to 1200 I get this:
>>>
>>> table 0.996464729309082
>>> object 0.747194766998291
>>>
>>> So it seems consistent. Are you able to try with a different
>>> database/client scenario to see if the issues you are seeing are 
>>> version
>>> specific?
>>
>> I retried on Linux with the same database:
>>
>> In [1] ▸ import cx_Oracle
>> In [2] ▸ cx_Oracle.clientversion()
>> Out[3] ▸ (11, 2, 0, 2, 0)
>> In [4] ▸ cx_Oracle.version
>> Out[4] ▸ '6.0.1'
>> In [5] ▸ db = cx_Oracle.connect("user/pwd@db")
>> In [6] ▸ db.version
>> Out[6] ▸ '11.2.0.1.0'
>>
>> With 1200 iterations I get:
>>
>> table 0.3604605197906494
>> object 0.8905477523803711
>> equal True
>>
>> With 1300 iterations I get:
>>
>> table 0.3804595470428467
>> object 42.898988246917725
>> equal True
>>
>> The strange thing is that
>>
>>    c.execute("select test_events2 from dual")
>>
>> takes 0.2 seconds and
>>
>>    objs = c.fetchone()[0].aslist()
>>
>> takes 0.1 seconds, but accessing the attributes takes 42 seconds.
>>
>> I also tried the script on Linux against a 12.1.0.2.0 database. The 
>> output:
>>
>> table 0.5058784484863281
>> object select 0.20530128479003906
>> object fetch 0.10213565826416016
>> object convert 110.43995141983032
>> object 110.74747037887573
>> equal True
>>
>> So maybe this problem is specific to the client version?
>>
>> Or it happens on all versions, but the threshold is higher?
>>
>
> I just tried with 11.2 client and I get similar responses to yours.
>
> 1200:
> table 0.9072585105895996
> object 0.710052490234375
>
> 1300:
> table 1.0106935501098633
> object 116.8638014793396
>
> With 12.1 client I also get similar numbers:
>
> 1200:
> table 0.9160842895507812
> object 0.7757439613342285
>
> 1300:
> table 1.0204412937164307
> object 118.60206842422485
>
> So apparently, this was a performance issue resolved in 12.2 client. 
> If you
> can upgrade, do it!

I'd like to, but

    http://www.oracle.com/technetwork/topics/intel-macsoft-096467.html

doesn't list any 12.2 version for the Mac.

> Anthony

Servus,
    Walter