Re: [cx-oracle-users] Unicode issue

[Uwe H. <uw...@fa...>]

Hi Anthony,

  see below.

Regards
     Uwe

Am 13.01.2012 23:37, schrieb Anthony Tuininga:
> Hi,
>
> I just had a chance to test this out. This is "normal" and "expected"
> behavior -- not what you want but that's a different thing!

;-)


>> I tested
> this with nvarchar2 instead of varchar2 and in that situation *both*
> string and unicode parameters work equally well.

Yup , I had expected this. But that's not a very practical solution. 
 From my view of a *client* developer that means: Using unicode
with cx_Oracle is tough (For example you can use custom Cursor classes 
making a parameter conversion from unicode to str on the fly).
You have to touch every application when moving from 5.0.4 to 5.1.x.

As a side note: What does this mean (performance wise) for python3.x
and varchar2 attributes. I haven't tested this.


You can also add this
> line
>
> cursor.setinputsizes(P1 = str)
>
> That will force Oracle to treat it as a string (instead of Unicode)
> and then all is well as well.
>
If you have large applications with many queries it's also impractical 
to touch every query.


> Hope that helps.

>
> Anthony
>
> 2011/12/6 Brian Watson<bw...@ma...>:
>> Hello everyone,
>>
>> I'm referencing bug 3442096:
>>
>> https://sourceforge.net/tracker/index.php?func=detail&aid=3442096&group_id=84168&atid=571972
>>
>> We just updated a webapp from SQLAlchemy 0.4 to 0.7.3.  Once we went live,
>> the server slowed to a crawl.  We put them back on their old server while we
>> diagnosed.  I hadn't noticed before, but the new orm emits unicode
>> parameters.  The unicode version is much slower:
>>
>> 2011-12-06 14:12:24,439 INFO sqlalchemy.engine.base.Engine SELECT
>> [......CUT......]
>> FROM demp_inventory
>> WHERE demp_inventory.inventory_snsn = :inventory_snsn_1 AND
>> demp_inventory.inventory_slocation = :inventory_slocation_1 AND
>> demp_inventory.inventory_sentityid = :inventory_sentityid_1 AND
>> demp_inventory.inventory_scc = :inventory_scc_1 AND
>> (demp_inventory.inventory_sshelflifeid IS NULL OR
>> demp_inventory.inventory_sshelflifeid = :inventory_sshelflifeid_1) AND
>> (demp_inventory.inventory_sserialno IS NULL OR
>> demp_inventory.inventory_sserialno = :inventory_sserialno_1))
>> WHERE ROWNUM<= :ROWNUM_1
>> 2011-12-06 14:12:24,439 INFO sqlalchemy.engine.base.Engine
>> {'inventory_snsn_1': u'0000LLCQA7546', 'inventory_slocation_1':
>> u'JNK1234114', 'inventory_sserialno_1': '', 'ROWNUM_1': 1,
>> 'inventory_sentityid_1': u'bae9b856-d874-11df-89f4-0022191e6cbe',
>> 'inventory_sshelflifeid_1': '', 'inventory_scc_1': u'A'}
>>
>> 0.419656 seconds to execute
>>
>>
>> 2011-12-06 13:59:15,882 INFO sqlalchemy.engine.base.Engine SELECT
>> [......CUT......]
>> FROM demp_inventory
>> WHERE demp_inventory.inventory_snsn = :inventory_snsn_1 AND
>> demp_inventory.inventory_slocation = :inventory_slocation_1 AND
>> demp_inventory.inventory_sentityid = :inventory_sentityid_1 AND
>> demp_inventory.inventory_scc = :inventory_scc_1 AND
>> (demp_inventory.inventory_sshelflifeid IS NULL OR
>> demp_inventory.inventory_sshelflifeid = :inventory_sshelflifeid_1) AND
>> (demp_inventory.inventory_sserialno IS NULL OR
>> demp_inventory.inventory_sserialno = :inventory_sserialno_1))
>> WHERE ROWNUM<= :ROWNUM_1
>> 2011-12-06 13:59:15,882 INFO sqlalchemy.engine.base.Engine
>> {'inventory_snsn_1': '0000LLCQA7546', 'inventory_slocation_1': 'JNK1234114',
>> 'inventory_sserialno_1': '', 'ROWNUM_1': 1, 'inventory_sentityid_1':
>> 'bae9b856-d874-11df-89f4-0022191e6cbe', 'inventory_sshelflifeid_1': '',
>> 'inventory_scc_1': 'A'}
>>
>> 0.014337 seconds to execute
>>
>> I've tested on cx_Oracle 5.0.3, 5.0.4, and 5.1.1 with identical results.
>>   I've learned my lesson on deployment, and I'll never do another rollout
>> without performance testing first.  I've tried various fixes so far with no
>> luck.  I've downloaded the source to try and diagnose my own problem, but
>> thats easier said than done.  I'm trying to get sqla to nix unicode params.
>>   If anyone has any suggestions or things to try, PLEASE let me know.  We use
>> cx in production and would buy support or donate to solve our issue.
>>
>> Many thanks,
>> Brian Watson
>>
>> ------------------------------------------------------------------------------
>> Cloud Services Checklist: Pricing and Packaging Optimization
>> This white paper is intended to serve as a reference, checklist and point of
>> discussion for anyone considering optimizing the pricing and packaging model
>> of a cloud services business. Read Now!
>> http://www.accelacomm.com/jaw/sfnl/114/51491232/
>> _______________________________________________
>> cx-oracle-users mailing list
>> cx-...@li...
>> https://lists.sourceforge.net/lists/listinfo/cx-oracle-users
>>
>
> ------------------------------------------------------------------------------
> RSA(R) Conference 2012
> Mar 27 - Feb 2
> Save $400 by Jan. 27
> Register now!
> http://p.sf.net/sfu/rsa-sfdev2dev2