Microsoft KB Archive/180015

= PRB: Stored Procedures Slower with MS Oracle ODBC Driver 2.0 =

Article ID: 180015

Article Last Modified on 2/14/2005

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APPLIES TO


 * Microsoft Visual Basic 5.0 Enterprise Edition
 * Microsoft Open Database Connectivity 2.0
 * Microsoft Open Database Connectivity 2.0
 * Microsoft Open Database Connectivity 2.0
 * Microsoft Open Database Connectivity 2.5

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This article was previously published under Q180015



SYMPTOMS
When you call an Oracle stored procedure through Remote Data Objects (RDO) or through ActiveX Data Objects (ADO) using Command.Refresh, the Microsoft Oracle ODBC Driver version 2.0 is slower than version 1.0.



CAUSE
The underlying ODBC API call (SQLProcedureColumns) was changed in version 2.0 of the MS Oracle ODBC Driver to accommodate Oracle package support. By making this change, the SQL for the API call increased ten-fold. The larger SQL statement results in the slower execution of Oracle stored procedures.



RESOLUTION
When using RDO there is no workaround. SQLProcedureColumns is always called. With ADO, if all of the Command attributes are set, the parameters collection is defined and Command.Refresh is not used, then SQLProcedureColumns is not called. For an example of how to use ADO so that SQLProcedureColumns is not called, please see the following article in the Microsoft Knowledge Base:

176936 INFO: Visual Basic Accessing an Oracle Database Using ADO



STATUS
Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.



MORE INFORMATION
Following is the SQL statement that SQLProcedureColumns creates on Oracle (captured through Oracle SQL trace): select null,owner,decode(package_name,NULL,object_name,  package_name||'.'||object_name),decode(position,0,   'RETURN_VALUE',nvl(argument_name,chr(0))), decode(data_type,'REFCURSOR',3,decode(in_out, 'IN',1,'IN/OUT',2,'OUT',decode(argument_name,null,5,4) ,0)), decode(data_type, 'CHAR', 1, 'DATE', 11, 'FLOAT' , 8, 'LONG', -1, 'LONG RAW', -4, 'NUMBER', 3, 'RAW', -3,   'VARCHAR2', 12, 0), data_type, decode(data_type, 'CHAR',   decode(data_length, null, 255, data_length), 'DATE', 19,   'FLOAT', 15, 'LONG', 2147483647, 'LONG RAW', 2147483647,   'NUMBER', decode(data_precision, null, 38, data_precision),   'RAW', decode(data_length, null, 255, data_length),   'VARCHAR2', decode(data_length, null, 2000, data_length),   data_length), decode(data_type, 'CHAR', decode(data_length, null, 255, data_length), 'DATE', 16, 'FLOAT', 8, 'LONG',  2147483647, 'LONG RAW', 2147483647, 'NUMBER', decode( data_precision, null, decode(data_scale, 0, 40, 40), 40),  'RAW', decode(data_length, null, 255, data_length),   'VARCHAR2', decode(data_length, null, 2000, data_length),   data_length), decode(data_type, 'DATE', 0, 'FLOAT', null,   'NUMBER', 0, data_scale), decode(data_type, 'NUMBER', 10,   'FLOAT', 10, 'DATE', 10, null), 2, null, overload,  sequence from all_arguments where data_level = 0 and decode(package_name,NULL,object_name,package_name||'.'||  object_name) like 'PACKPERSON.ONEPERSON' escape '\' order by 2,3,14,15 If you use ADO (as demonstrated in KB article 176936) instead of RDO, the above statement is never issued to Oracle. Because of this, ADO can execute an Oracle stored procedure much faster than RDO.

Additional query words: MS Oracle ODBC Driver rdo ado stored procedure

Keywords: kboracle kbrdo kbdatabase kbprb kbdriver KB180015

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