EXTREMELY SLOW XQUERY PERFORMANCE AND SLOW DOCUMENT INSERTS

Question

EXTREMELY SLOW XQUERY PERFORMANCE AND SLOW DOCUMENT INSERTS.
Resolution History
12-JUN-07 15:01:17 GMT
### Complete Problem Description ###
A test file is being used to do inserts into a schemaless XML DB. The file is inserted and then links are made to 4
different collection folders under /public. The inserts are pretty slow (about
15 per second and the file is small)but the xquery doesn't even complete when
there are 500 documents to query against.
The same xquery has been tested on a competitors system and it has lightening fast performance there. I know it
should likewise be fast on Oracle, but I haven't been able to figure out what
is going on except that I suspect somehow a cartesian product is the result of
the query on Oracle.
### SQLXML, XQUERY, PL/SQL syntax used ###
Here is the key plsql code that calls the DBMS_XDB procedures:
CREATE OR REPLACE TYPE "XDB"."RESOURCEARRAY" AS VARRAY(500) OF VARCHAR2(256);
PROCEDURE AddOrReplaceResource(
resourceUri VARCHAR2,
resourceContents SYS.XMLTYPE,
public_collections in ResourceArray
) AS
b BOOLEAN;
privateResourceUri path_view.path%TYPE;
resource_exists EXCEPTION;
pragma exception_init(resource_exists,-31003);
BEGIN
/* Store the document in private folder */
privateResourceUri := GetPrivateResourceUri(resourceUri);
BEGIN
b := dbms_xdb.createResource(privateResourceUri, resourceContents);
EXCEPTION
WHEN resource_exists THEN
DELETE FROM resource_view WHERE equals_path(res, privateResourceUri)=1;
b := dbms_xdb.createResource(privateResourceUri, resourceContents);
END;
/* add a link in /public/<collection-name> for each collection passed in */
FOR i IN 1 .. public_collections.count LOOP
BEGIN
dbms_xdb.link(privateResourceUri,public_collections(i),resourceUri);
EXCEPTION
WHEN resource_exists THEN
dbms_xdb.deleteResource(concat(concat(public_collections(i),'/'),resourceUri));
dbms_xdb.link(privateResourceUri,public_collections(i),resourceUri);
END;
END LOOP;
COMMIT;
END;
FUNCTION GetPrivateResourceUri(
resourceUri VARCHAR2
) RETURN VARCHAR2 AS
BEGIN
return concat('/ems/docs/',REGEXP_SUBSTR(resourceUri,'[a-zA-z0-9.-]*$'));
END;
### Info for XML Querying ###
Here is the XQuery and a sample of the output follows:
declare namespace c2ns="urn:xmlns:NCC-C2IEDM";
for $cotEvent in collection("/public")/event
return
<cotEntity>
{$cotEvent}
{for $d in collection("/public")/c2ns:OpContextMembership[c2ns:Entity/c2ns:EntityIdentifier
/c2ns:EntityId=xs:string($cotEvent/@uid)]
return
$d
</cotEntity>
Sample output:
<cotEntity><event how="m-r" opex="o-" version="2" uid="XXX541113454" type="a-h-G-" stale="2007-03-05T15:36:26.000Z"
start="2007-03-
05T15:36:26.000Z" time="2007-03-05T15:36:26.000Z"><point ce="" le="" lat="5.19098483230079" lon="-5.333597827082126"
hae="0.0"/><de
tail><track course="26.0" speed="9.26"/></detail></event></cotEntity>

Answer 1

19-JUN-07 04:34:27 GMT
UPDATE
=======
Hi Arnold,
you wrote -
Please use Sun JDK 1.5 java to perform the test case.Right now I have -
$ which java
/usr/bin/java
$ java -version
java version "1.4.2"
gcj (GCC) 3.4.6 20060404 (Red Hat 3.4.6-3)
sorry as I told you before I am not very knowledgeable in Java. Can you tell me what setting
s I need to change to make use of Sun JDK 1.5. Please note I am testing on Linux
. Do I need to test this on a SUN box? Can it not be modify to run on Linux?
Thanks,
Rakesh
STATUS
=======
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