Issues with using XMLType indexes against a table with XMLType column

Question

I am attempting to use an XMLIndex with a Structured Component and not having too much luck. Not much data in metalink nor is the documentation very helpful:
http://download.oracle.com/docs/cd/E11882_01/appdev.112/e10492/xdb_indexing.htm#BCGHGIGC
The table DDL is as follows:
CREATE TABLE ECI_SCHEMA.REV_ITEM_EARN_DTL_VIRTUAL(
REV_ITEM_EARN_DTL_ID_NBR NUMBER(16,0) NOT NULL,
UNIQ_MSG_ID_NBR VARCHAR2(50) NOT NULL,
REV_ITEM_BILL_DTL_ID_NBR NUMBER(16,0),
PLAN_RACN_NBR NUMBER(10,0) NOT NULL,
INV_DTL_IMG SYS.XMLType NOT NULL,
NON_INV_DTL_IMG BLOB NOT NULL,
PART_KEY_CD GENERATED ALWAYS AS (MOD(PLAN_RACN_NBR,5)) VIRTUAL,
LAST_UPDT_TMSTP TIMESTAMP(6) NOT NULL,
INV_ID_NBR NUMBER(16,0),
ITEM_STATUS_CD VARCHAR2(1) DEFAULT 'A' NOT NULL
LOB (NON_INV_DTL_IMG) STORE AS NON_IDI_LOB (CHUNK 8192 PCTVERSION 10 CACHE)
TABLESPACE ECI_DATA
PARTITION BY RANGE (PART_KEY_CD)
PARTITION RIED_DAY0_PART
VALUES LESS THAN (1)
TABLESPACE ECI_DATA
PARTITION RIED_DAY1_PART
VALUES LESS THAN (2)
TABLESPACE ECI_DATA
PARTITION RIED_DAY2_PART
VALUES LESS THAN (3)
TABLESPACE ECI_DATA
PARTITION RIED_DAY3_PART
VALUES LESS THAN (4)
TABLESPACE ECI_DATA
PARTITION RIED_MAXVAL_PART
VALUES LESS THAN (MAXVALUE)
TABLESPACE ECI_DATA
XMLTYPE COLUMN "INV_DTL_IMG" STORE AS OBJECT RELATIONAL
XMLSCHEMA "someXdbDocument.xsd"
ELEMENT "revenueInvoice"
According to the documentation, I should be able to create a structured XMLIndex on the XMLType column with the following syntax:
SQL> create index eci_schema.rev_item_earn_dtl_virt_xmlix on eci_schema.rev_item_earn_dtl_virtual
2 (INV_DTL_IMG)
3 INDEXTYPE IS XDB.XMLIndex
4 parameters ('PATH TABLE RIED_PATH_TABLE')
5 local;
When I do this, I get the following error:
create index eci_schema.rev_item_earn_dtl_virt_xmlix on eci_schema.rev_item_earn_dtl_virtual
ERROR at line 1:
ORA-29958: fatal error occurred in the execution of ODCIINDEXCREATE routine
ORA-30959: The indexed column is not stored in CLOB.
What am I doing wrong? Based on the Oracle documentation, I was under the impression that 11.2 XMLIndex would work with Object Relational storage. Is this not the case?

Answer 1

CREATE INDEX ECI_SCHEMA.REV_ITEM_EARN_DTL_IX7
       ON ECI_SCHEMA.REV_ITEM_EARN_DTL
                  extractValue(inv_dtl_img, '/revenueInvoice/service/transportation/mstrTrkngNbr')
TABLESPACE ECI_REV_ITEM_EARN_DTL_IX7_ITS
LOGGING
PARALLEL(DEGREE 8 INSTANCES 1)
LOCAL
/Elements that occur at most once in each document can be indexed using extractValue(). Despite the fact that the index appears to be a functional index, when we create the index we automatically re-write the create index into a normal btree index on the column that contains the value for the element identified by the xpath.
Eg in the case of a functional index based on extractValue, defined on XMLType using Object relational storage, with an xpath that identifies a node that occurs at most once in each document is not a functional index, it's re-written into a plain old vanilla btree index. You can actually check this by looking in the system tables
Eg
SQL> connect system/oracle
Connected.
SQL> select table_name, index_name from all_indexes where owner = 'OE' and table_name = 'PURCHASEORDER';
TABLE_NAME                     INDEX_NAME
PURCHASEORDER                  LINEITEM_TABLE_MEMBERS
PURCHASEORDER                  ACTION_TABLE_MEMBERS
PURCHASEORDER                  SYS_C0011037
SQL> alter session set current_schema = OE
  2  /
Session altered.
SQL> create unique index PO_REF_INDEX on PURCHASEORDER (extractValue(object_value,'/PurchaseOrder/Reference'));
Index created.
SQL> set lines 250
SQL> select index_name, index_type from all_indexes where owner = 'OE' and table_name = 'PURCHASEORDER';
INDEX_NAME                     INDEX_TYPE
PO_REF_INDEX                   NORMAL
LINEITEM_TABLE_MEMBERS         NORMAL
ACTION_TABLE_MEMBERS           NORMAL
SYS_C0011037                   NORMAL
SQL> select * from dba_ind_expressions where table_name = 'PURCHASEORDER' and index_owner = 'OE'
  2  /
no rows selectedFrom the above we can see that the index created on extractValue has been re-written in a plain old vanilla BTREE index, and there is no definition for it in dba_ind_expressions So assuming you were able to create the index and insert the data you should find that your index is not a functional index.
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