Another performance problem

Question

Hi! I have following data structure - site/buyers/buyer/notices/notice/noticesTexts/noticeText defined in corresponding .xsd file. The storage type is schema based and structured.
I make data import to XML DB using appendChildXML(). So to add another buyer I call something like this: UPDATE xml_site SET OBJECT_VALUE = appendChildXML(OBJECT_VALUE,"/site/buyers", XMLType(?))
The issue is that performance degrades with the growth of nodes quantity - it takes 20ms to add buyer #30 and it takes 2000ms to add buyer #600.
Is this normal situation or am I doing something wrong?

Answer 1

Hm, the problem is then I use appendChildXML with the full path, appendChildXML just replaces child, not appends another one. You can see this in the output below :
Connect xxx/yyy@zzz
DELETE FROM "SCOTT"."xml_market";
INSERT INTO "SCOTT"."xml_market" VALUES(XMLType('<market><site><buyers></buyers></site></market>'));
UPDATE "SCOTT"."xml_market" SET OBJECT_VALUE = appendChildXML(OBJECT_VALUE,'/market/site/buyers', XMLType('<buyer buyerId="1"/>'));
SELECT extract(object_value,'/market/site/buyers') FROM "SCOTT"."xml_market";
UPDATE "SCOTT"."xml_market" SET OBJECT_VALUE = appendChildXML(OBJECT_VALUE,'/market/site/buyers', XMLType('<buyer buyerId="2"/>'));
SELECT extract(object_value,'/market/site/buyers') FROM "SCOTT"."xml_market";
UPDATE "SCOTT"."xml_market" SET OBJECT_VALUE = appendChildXML(OBJECT_VALUE,'//buyers', XMLType('<buyer buyerId="3"/>'));
SELECT extract(object_value,'/market/site/buyers') FROM "SCOTT"."xml_market";
UPDATE "SCOTT"."xml_market" SET OBJECT_VALUE = appendChildXML(OBJECT_VALUE,'//buyers', XMLType('<buyer buyerId="4"/>'));
SELECT extract(object_value,'/market/site/buyers') FROM "SCOTT"."xml_market";
Connected.
1 row removed.
1 row created.
1 row updated.
EXTRACT(OBJECT_VALUE,'/MARKET/SITE/BUYERS')
<buyers>
<buyer buyerId="1"/>
</buyers>
1 row selected.
1 row updated.
EXTRACT(OBJECT_VALUE,'/MARKET/SITE/BUYERS')
<buyers>
<buyer buyerId="2"/>
</buyers>
1 row selected.
1 row updated.
EXTRACT(OBJECT_VALUE,'/MARKET/SITE/BUYERS')
<buyers>
<buyer buyerId="2"/>
<buyer buyerId="3"/>
</buyers>
1 row selected.
1 row updated.
EXTRACT(OBJECT_VALUE,'/MARKET/SITE/BUYERS')
<buyers>
<buyer buyerId="2"/>
<buyer buyerId="3"/>
<buyer buyerId="4"/>
</buyers>
1 row selected.
So, good execution times were because of this "replacement"- there always was one buyer. If I use "//buyers" path - appendChildXML works properly - buyers are add correctly, but execution times grow respectively to the growth of nodes count - still have 2-5 sec on adding buyer #600, regardless of the domFidelity set to false. Also I found out that insertChildXML works fine with the full path "/market/site/buyers", but execution times grow the same way.
BTW I followed big red button "DOWNLOAD ORACLE SOFTWARE" and I can't find 10.2.0.3 for windows - only 10.2.0.1.