Extract() problem in Enterprise manager

Question

OEM issues queries like the following one in several places:
/* OracleOEM */ SELECT c.extract('/element/@name', 'xmlns="http://www.w3.org/2001/XMLSchema"').getStringVal()
FROM  table(xmlsequence((
SELECT  s.schema.extract('//schema/element')
from dba_xml_schemas s
WHERE  s.schema_Url = 'http://www.agralin.nl/WebQuery/ns/data1' and s.owner ='AGE'))) cOne of these places is the clicking of the plus sign in front of an XML schema name, another one is in the definition of an xmltype column, if on the "xml type options" page the "xml schema based" option is selected. In both cases my test server seems to enter an endless loop. I have only one very large schema defined; the original text length is 122 KB, the internal Oracle version is at least 140KB.
A second instance of OEM tells me the execution plan is
1. collection iterator (pickler fectch)
2. select statement
After running for about two hours I killed the server thread, which was by then consuming over half a gigabyte of PGA memory and over 90% of the CPU. I started the subquery in SQL*Plus:
SELECT  s.schema.extract('//schema/element')
FROM dba_xml_schemas s
WHERE  s.schema_Url = 'http://www.agralin.nl/WebQuery/ns/data1' AND (s.owner =  'AGE')After about five minutes it was clear this query suffered the same problem (although with a different execution plan), so I aborted it as well. My final simplification:
SELECT  *
FROM dba_xml_schemas s
WHERE  s.schema_Url = 'http://www.agralin.nl/WebQuery/ns/data1' AND (s.owner =  'AGE'))took half a minute with long set to 140000, giving almost the full element text. I did a count(*) to be sure the result set consisted of just one record. Earlier tests, with very simple xmlschema's did respond normally, so I guess the length of my schema is part of the problem.
Is this a known bug, or can anybody give me a workaround?
Age Jan

Answer 1

Again:
ORA-00955: name is already used by an existing object
--edited, i posted a blog but i didn't like it too much:
Starting with step 1) emca -deconfig dbcontrol db -repos drop
later estep 2 (a bit modified):
SQL>> DECLARE
  2  CURSOR c1 IS
  3  SELECT owner, synonym_name name
  4  FROM dba_synonyms
  5  WHERE table_owner = 'SYSMAN';
  6  BEGIN
  7  FOR r1 IN c1 LOOP
  8  IF r1.owner = 'PUBLIC' THEN
  9  EXECUTE IMMEDIATE 'DROP PUBLIC SYNONYM '||r1.name;
10  ELSE
11  EXECUTE IMMEDIATE 'DROP SYNONYM '||r1.owner||'.'||r1.name;
12  END IF;
13  END LOOP;
14  END;
15  /
DROP USER SYSMAN CASCADE;
DROP PUBLIC SYNONYM SETEMVIEWUSERCONTEXT;
DROP ROLE MGMT_USER;
DROP PUBLIC SYNONYM MGMT_TARGET_BLACKOUTS;
DROP USER MGMT_VIEW;
An advide: logs can told you a lot of information, you should read them in detail.