Function based index Issue

Hi Guys,
We are running Oracle 8.1.7 Database on Solaris server. We created function based indexes, while executing queries the function based indexes are not being used. Only if we use a hint in the query the indexes are being used. Is this a bug in oracle 8.1.7 or is this is how the function based indexes have to be used. Can somebody clarify this issue, I will appreciate your help. Thanks in advance.

First, have you analyzed the tables recently? I believe you have to be using the CBO if you're using function based indexes. If the CBO has bad statistics, it may be generating bad plans.
Second, can you post the query & the plan (with and without the hint)? Is it possible that the CBO is finding a better plan than using the index?
Justin

Similar Messages

Query not considering function based index in oracle 11g

I have a query which used Function Based Index when run in oracle 9i but when I run the same query
without any changes, it does not consider index. Below is the query:
SELECT distinct patient_role.domain_key, patient_role.patient_role_key,
patient_role.emergency_contact_name,
patient_role.emergency_contact_phone, patient_role.emergency_contact_note,
patient_role.emergency_contact_relation_id,
patient_role.financial_class_desc_id, no_known_allergies, patient_role.CREATED_BY,
patient_role.CREATED_TIMESTAMP,
patient_role.CREATED_TIMESTAMP_TZ, patient_role.UPDATED_BY, patient_role.UPDATED_TIMESTAMP,
patient_role.UPDATED_TIMESTAMP_TZ,
patient_role.discontinued_date
FROM encounter, patient_role
WHERE patient_role.patient_role_key = encounter.patient_role_key
AND UPPER(TRIM(leading :SYS_B_0 from encounter.account_number)) = UPPER(TRIM(leading :SYS_B_1 from
:SYS_B_2))
AND patient_role.discontinued_date IS null
AND encounter.discontinued_date IS null ;
Index definition:
CREATE INDEX "user1"."IX_TRIM_ACCOUNT_NUMBER" ON "user1."ENCOUNTER" (UPPER(TRIM(LEADING
'0' FROM "ACCOUNT_NUMBER")), "PATIENT_ROLE_KEY", "DOMAIN_KEY", "DISCONTINUED_DATE")
PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT)
TABLESPACE "user1"
Database : Oracle 11g (11.2.0.3)
O/S : Linux 64 bit (the query does not consider index even on windows os)
Any suggestions?
-Onkar
Edited by: onkar.nath on Jul 2, 2012 3:32 PM

Onkar,
I don't appreciate you posting this question in several forums at the same time.
If I would know you also posted this on Asktom, I wouldn't even have bothered.
As to your 'issue':
First of all: somehow cursor_sharing MUST have been set to FORCE. Oracle is a predictable system, not a fruitmachine.
Your statement the '0' is replaced by a bind variable anyway is simply false. If you really believe it is not false, SUBMIT a SR.
But your real issue is not Oracle: it is your 'application', which is a mess anyway. Allowing for alphanumeric numbers is a really bad idea.
Right now you are already putting workaround on workaround on workaround on workaround.
Issue is the application: it is terminal., and you either need to kill it, or to replace it.
Sybrand Bakker
Senior Oracle DBA

Unable to create function based Index

Hi All,
I created a function as below:
create or replace function eqx_oklb_term_date_nvl(pin_term_date date)
return date
deterministic
is
l_sub_date date := sysdate+1;
l_return_value date := l_sub_date;
begin
l_return_value := nvl(pin_term_date, l_sub_date);
return l_return_value;
exception
when others
then
l_return_value := l_sub_date;
return l_return_value;
end eqx_oklb_term_date_nvl;
Now trying to create a function based index using below code:
create index EQX_OKC_K_LINES_B_N4 on OKC.OKC_K_LINES_B(EQX_OKLB_TERM_DATE_NVL(DATE_TERMINATED))
logging
tablespace EQIXDATA
noparallel;
Encountered Error:
SQL Error: ORA-00904: "EQX_OKLB_TERM_DATE_NVL": invalid identifier
00904. 00000 - "%s: invalid identifier"
*Cause:
*Action:
I can successfully query dba_objects for the function.
Owner Object_name object_id object_type last_ddl_time status
APPS EQX_OKLB_TERM_DATE_NVL 11764623 FUNCTION 3/4/2013 9:44:57 PM VALID
I can also query the function using dual.
select eqx_oklb_term_date_nvl(null) nvl_date from dual;
nvl_date
3/5/2013 9:53:59 PM
I have given grants of the function to both schemas APPS/OKC
grant all on eqx_oklb_term_date_nvl to okc;
grant all on eqx_oklb_term_date_nvl to apps;
The column date_terminated in table okc_k_lines_b is a date. I've checked that.
Stuck here. Please help.
Thanks in advance,
Rahul

Hi,
To follow up, the below code resolved the issue:
create index EQX_OKC_K_LINES_B_N4 on okc_k_lines_b(apps.eqx_oklb_term_date_nvl(date_terminated))
logging
tablespace eqixdata
noparallel;
-- qualifying the custom function name with schema name resolved the issue.
Thanks,
Rahul

Function Based index getting disabled frequently

I am facing some error like “ORA-30554: function-based index ORADB1.FUN_INDX1 is disabled” in the development database. I verified that the function which is referred by the index is valid. Once I even got the tedious generic error ORA-600 because of this. I referred the metalink and advised to drop and recreate the index
Dropping and recreating the index will solve the issue for 2-3 days and again the same will be repeated. So what I did is made the index unusable as it will not affect the other application activities. Can anybody give a clue on this issue?

I am facing some error like “ORA-30554:
function-based index ORADB1.FUN_INDX1 is disabled” Cause: An attempt was made to access a function-based index that has been marked disabled because the function on which the index depends has been changed.
Action: Perform one of the following actions: -- drop the specified index using the DROP INDEX command -- rebuild the specified index using the ALTER INDEX REBUILD command -- enable the specified index using the ALTER INDEX ENABLE command -- make the specified index usable using the ALTER INDEX UNUSABLE command

Function-Based Index enabling.

Hi...
I'm trying to create a function-based index along the lines of:
CREATE INDEX x_ssn4
ON table_y(SUBSTR(ssn,6,4))
UNRECOVERABLE;
...so as to be able to query the final 4 digits of social security numbers. Problem is that the above elicits an ORA-00439 "feature not enabled" message. I'm running 8.1.6 and have tried setting the Oracle parameter QUERY_REWRITE_ENABLED to 'TRUE' via an ALTER SESSION command, but to no avail.
Anyone know how to 'turn the feature on'?
Thanks, Rob

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Rick Post:
I've always done it by logging on as SYS and executing a 'grant query rewrite to myuser'.
<HR></BLOCKQUOTE>
Thanks... but turns out that the privilege is not really the issue, as the ALTER SESSION command works. I figured out that the problem was the setting for COMPATIBLE. It pointed to 8.0.0 instead of 8.1.x which is what was needed to permit function-based indexing.
~Rob
null

Query Transformation in Function Based Index's Expression

Hi All,
I am having a wired issue with Function Based Indexes on Orcale 10.2.0.3 running on Solaris 5.9.
I have created two FBI on two tables using following syntax.
CREATE INDEX EQHUB.IDX_BBO_WRT_DES_FBI ON EQHUB.BBO_WARRANT_PRICING (CASE WHEN latest_version_flag = 'Y' THEN 1 ELSE NULL END);
CREATE INDEX EQHUB.IDX_BBO_DES_FBI ON EQHUB.BBO_DESCRIPTIVE_DATA (CASE WHEN latest_version_flag = 'Y' THEN 1 ELSE NULL END);
For the second command (IDX_BBO_DES_FBI), when i query DBA_IND_EXPRESSIONS view, i found that Oracle has done some kind of QUERY TRANSFORMATION (?) and converted
FBI expression to CASE "LATEST_VERSION_FLAG" WHEN 'Y' THEN 1 ELSE NULL END.At the same time,EXPRESSION on first index is not changed.
Now,my question is what has made transformation to occure only for second index.
I also found that inspite of highly SELECTIVE nature of both the indexes, only SECOND index is being used by CBO (for which trasnformation occured)
and IDX_BBO_WRT_DES_FBI is not being used(FTS is happening instead).
Query is using same expression for both the tables as
(CASE WHEN latest_version_flag = 'Y' THEN 1 ELSE NULL END)=1
INDEX_NAME                          TABLE_NAME                          COLUMN_EXPRESSION
IDX_BBO_WRT_DES_FBI                 BBO_WARRANT_PRICING                 CASE WHEN "LATEST_VERSION_FLAG"='Y' THEN 1 ELSE NULL END
IDX_BBO_DES_FBI                     BBO_DESCRIPTIVE_DATA                CASE "LATEST_VERSION_FLAG" WHEN 'Y' THEN 1 ELSE NULL ENDI read that expression should be evaluated including CASE of characters and spaces in query.Is that true?
Appreciating responses in advance.

Randolf.
It's a shame that I forgot to look into the full execution plan information to check how Oracle really handles my queries.
Look here(edited for clarity):
explain plan for
select /*+ case1 ordered use_nl(x, y) */ count(case c1
    when '1' then 1
    when '2' then 2
    when '3' then 3
    else 4
end) from
(select level from dual connect by level <= 300000) x,
(select
from t1
) y;
| Id | Operation                       | Name | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT                |      |     1 |     2 |     5   (0)| 00:00:01 |
|   1 | SORT AGGREGATE                 |      |     1 |     2 |            |          |
|   2 |   NESTED LOOPS                  |      |     3 |     6 |     5   (0)| 00:00:01 |
|   3 |    VIEW                         |      |     1 |       |     2   (0)| 00:00:01 |
|   4 |     CONNECT BY WITHOUT FILTERING|      |       |       |            |          |
|   5 |      FAST DUAL                  |      |     1 |       |     2   (0)| 00:00:01 |
|   6 |    TABLE ACCESS FULL            | T1   |     3 |     6 |     3   (0)| 00:00:01 |
Column Projection Information (identified by operation id):
   1 - (#keys=0) COUNT(CASE WHEN "T1"."C1"='1' THEN 1 WHEN "T1"."C1"='2' THEN
       2 WHEN "T1"."C1"='3' THEN 3 ELSE 4 END )[22]
   2 - (#keys=0) "T1"."C1"[CHARACTER,1]
   4 - "DUAL".ROWID[ROWID,10], LEVEL[4]
   5 - "DUAL".ROWID[ROWID,10]
   6 - "T1"."C1"[CHARACTER,1]
32 rows selected.
explain plan for select /*+ case2 ordered use_nl(x, y) */ count(case
    when c1 = '1' then 1
    when c1 = '2' then 2
    when c1 = '3' then 3
    else 4
end) from
(select level from dual connect by level <= 300000) x,
(select
from t1
) y;
| Id | Operation                       | Name | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT                |      |     1 |     2 |     5   (0)| 00:00:01 |
|   1 | SORT AGGREGATE                 |      |     1 |     2 |            |          |
|   2 |   NESTED LOOPS                  |      |     3 |     6 |     5   (0)| 00:00:01 |
|   3 |    VIEW                         |      |     1 |       |     2   (0)| 00:00:01 |
|   4 |     CONNECT BY WITHOUT FILTERING|      |       |       |            |          |
|   5 |      FAST DUAL                  |      |     1 |       |     2   (0)| 00:00:01 |
|   6 |    TABLE ACCESS FULL            | T1   |     3 |     6 |     3   (0)| 00:00:01 |
Column Projection Information (identified by operation id):
   1 - (#keys=0) COUNT(CASE WHEN "T1"."C1"='1' THEN 1 WHEN "T1"."C1"='2' THEN
       2 WHEN "T1"."C1"='3' THEN 3 ELSE 4 END )[22]
   2 - (#keys=0) "T1"."C1"[CHARACTER,1]
   4 - "DUAL".ROWID[ROWID,10], LEVEL[4]
   5 - "DUAL".ROWID[ROWID,10]
   6 - "T1"."C1"[CHARACTER,1]As you exactly mentioned, I was executing different SQL but actually same queries!
Thanks for pointing my flaws.
PS) OP, forgive me for bothering you with off-topic things. :)
================================
Dion Cho - Oracle Performance Storyteller
http://dioncho.wordpress.com (english)
http://ukja.tistory.com (korean)
================================
Edited by: Dion_Cho on Feb 10, 2009 5:45 AM
Typo

Importing error: related to function-based indexes?

I've come across a strange error. I've got a user that has an export dump file who wants me to import the data into a new database. (Its an Oracle 10G database.)
When I use the 'imp' command, the table import completes successfully, but I end up receiving the following warnings:
IMP-00003: oracle error 942 encountered
ORA-00942: table or view does not exist
IMP-00017: following statement failed with ORACLE error 942
"CREATE INDEX "X" on "Y" (TO_CHAR("Z",'yyyymmdd')) P"
"CTFREE 10 INITRANS 2 MAXTRANS 255 STORAGE(INITIAL 3145728 FREELISTS 1 FREEL"
"IST GROUPS 1 BUFFER_POOL DEFAULT) TABLESPACE "TBSPC" LOGGING"
The table itself seems to have been imported correctly; and all data rows exist. Its just the index that isn't being imported/rebuilt. (Other indexes on the same table were imported properly.)
The only thing that I could find that seems odd is that this index uses functions (the "TO_CHAR" in the index above). All of the other indexes on the table refer to basic fields. And I can rebuild the index manually.
Is the 'imp' command able to handle function-based indexes? Is there some parameter than I need to set to allow it to import these indexes?
(I know the more efficient thing to do would be to do an import with no indexes and rebuild them later...)
Edited by: user588235 on Dec 9, 2009 5:16 PM

Function based indexes should be supported. If it is exported, then it should be able to be imported. This just seems like a weird case. Have you tried to create a different table and then create a function based index on that table then see if exp/imp work?Yes, I have tried creating new versions of the tables (both with and without function-based indexes).
During my tests, I found that I can recreate the problem if I create the table in Oracle 9 and import it into Oracle 10; the problem doesn't occur when importing/exporting between Oracle9->Oracle9 or Oracle10->Oracle10. (However, the user told me that this was an export from Oracle 10.)
One other thing: I've noticed that if, instead of importing into a user account, I import into the system account, it works with no problems. For example:
imp userid='sys/xyz as sysdba' file=mydata.dmp fromuser=use1 touser=use2 ->Results in warnings while reading indexes
imp userid='sys/xyz as sysdba' file=mydata.dmp fromuser=use1 touser=sys ->works with no warning
This makes me suspect that its a problem with the permissions that have been granted. (I've granted 'create any index' and 'query rewrite' to the user account however.)
Not to change the issue, but since this is 10g, have you tried using datapump to expdp/impdp the same information?Might be an option; problem is, I'm dealing with a legacy system that was set up to use 'imp/exp', so altering backup and restore methods will require a lot of work.

Function Based Indexes - negative performance

Has anyone run across any cases where they have had issues with Function Based Indexes negatively impacting performance??
We are trying to use function based indexes in 9i (NLS_SORT=GENERIC_BASELETTER) and 10g (NLS_SORT=BINARY_CI) for case insensitivity.
We thought this was a decent solution until recently when testing with larger datasets. Any info is appreciated.
Thanks,

Just to clarify rreynoldson's first point:
All indexes will negatively impact inserts. Indexes, including function-based indexes, may or may not improve update and delete performance depending on whether the overhead of maintaining the index outweighs the benefit of being able to use the index to find the row(s) to update relatively quickly.
For user564260:
Assuming those parameters are set, make sure that you've gathered statistics on the function based index. If that doesn't resolve the problem, can you post a small test case that demonstrates the problem where you
- Create the table
- Create the indexes
- Populate it with data
- Run the query that you'd expect to use the FBI
- Post the explain plan
that would help us immensely.
Justin

Function Based Indexes Errors

Hi
I am trying to create function based indexes based on the examples in the b10826 Spatial Users guide --
The Create index statement is failing because it says it cannot read the metadata
create index EMITTER_LOB_WIDX ON EMITTER (OWNER1.WT_GEOMETRY_PACKAGE.LINEOFBEARING(EQUIP_X, EQUIP_Y, LOB_BEARING, LOB_RANGE)) INDEXTYPE IS MDSYS.SPATIAL_INDEX LOCAL;
create index EMITTER_LOB_WIDX ON EMITTER (EMITTER.WT_GEOMETRY_PACKAGE.LINEOFBEARING(EQUIP_X, EQUIP_Y, LOB_BEARING, LOB_RANGE)) INDEXTYPE IS MDSYS.SPATIAL_INDEX LOCAL
ERROR at line 1:
ORA-29855: error occurred in the execution of ODCIINDEXCREATE routine
ORA-13203: failed to read USER_SDO_GEOM_METADATA view
ORA-13203: failed to read USER_SDO_GEOM_METADATA view
ORA-06512: at "MDSYS.SDO_INDEX_METHOD_10I", line 10
Here is the USER_SDO_GEOM_METADATA ENTRY:
TABLE_NAME
COLUMN_NAME
DIMINFO(SDO_DIMNAME, SDO_LB, SDO_UB, SDO_TOLERANCE)
SRID
EMITTER
OWNER1.WT_GEOMETRY_PACKAGE.LINEOFBEARING(EQUIP_X, EQUIP_Y, LOB_BEARING,
LOB_RANGE)
SDO_DIM_ARRAY(SDO_DIM_ELEMENT('X', -180, 180, .00005), SDO_DIM_ELEMENT('Y', -90,
90, .000005))
TABLE_NAME
COLUMN_NAME
DIMINFO(SDO_DIMNAME, SDO_LB, SDO_UB, SDO_TOLERANCE)
SRID
8307
The package is owned by OWNER1 - the Table is in OWNER2's schema - not that that matters - what are the known issues with Function Based Indexes
Am I missing something Obvious?

I think its a bug
I moved the function to the local schema - I also pulled it out of the package -
So I look in USER_SDO_GEOM_METADATA no records for select * from USER_SDO_GEOM_METADATA
Not being satisfied with that I look in ALL_SDO_GEOM_METADATA
SELECT * FROM ALL_SDO_GEOM_METADATA WHERE OWNER = 'OWNER2';
no rows selected
So I should be good for insert
INSERT INTO USER_SDO_GEOM_METADATA VALUES ('EMITTER','OWNER2.EQUIPMENTPOINT(EQUIP_X, EQUIP_Y)', MDSYS.SDO_DIM_ARRAY(MDSYS.SDO_DIM_ELEMENT('X',-180,180,0.005),MDSYS.SDO_DIM_ELEMENT('Y',-90,90,0.005)), 8307);
INSERT INTO USER_SDO_GEOM_METADATA VALUES ('EMITTER','LOCUST2.EQUIPMENTPOINT(EQUIP_X, EQUIP_Y)', MDSYS.SDO_DIM_ARRAY(MDSYS.SDO_DIM_ELEMENT('X',-180,180,0.005),MDSYS.SDO_DIM_ELEMENT('Y',-90,90,0.005)), 8307)
ERROR at line 1:
ORA-13223: duplicate entry for EMITTER.OWNER2.EQUIPMENTPOINT(EQUIP_X, EQUIP_Y)
in SDO_GEOM_METADATA
ORA-06512: at "MDSYS.MD", line 1723
ORA-06512: at "MDSYS.MDERR", line 17
ORA-06512: at "MDSYS.SDO_GEOM_TRIG_INS1", line 21
ORA-04088: error during execution of trigger 'MDSYS.SDO_GEOM_TRIG_INS1'
If I insert to all_sdo_geom_metadata it takes but the index create fails b/c it cannot read user_sdo_geom_metadata
INSERT INTO ALL_SDO_GEOM_METADATA VALUES (OWNER2','EMITTER','OWNER2.EQUIPMENTPOINT(EQUIP_X, EQUIP_Y)', MDSYS.SDO_DIM_ARRAY(MDSYS.SDO_DIM_ELEMENT('X',-180,180,0.005),MDSYS.SDO_DIM_ELEMENT('Y',-90,90,0.005)), 8307);
1 row created.
SQL> CREATE INDEX EMITTER_EQUIP_WIDX ON EMITTER(OWNER2.EQUIPMENTPOINT(EQUIP_X, EQUIP_Y)) INDEXTYPE IS MDSYS.SPATIAL_INDEX PARAMETERS ('layer_gtype=point tablespace=EMITTER_IDX_TBS');
CREATE INDEX EMITTER_EQUIP_WIDX ON EMITTER(OWNER2.EQUIPMENTPOINT(EQUIP_X, EQUIP_Y)) INDEXTYPE IS MDSYS.SPATIAL_INDEX PARAMETERS ('layer_gtype=point tablespace=EMITTER_IDX_TBS')
ERROR at line 1:
ORA-29855: error occurred in the execution of ODCIINDEXCREATE routine
ORA-13203: failed to read USER_SDO_GEOM_METADATA view
ORA-13203: failed to read USER_SDO_GEOM_METADATA view
ORA-06512: at "MDSYS.SDO_INDEX_METHOD_10I", line 10
select table_name, column_name from user_sdo_geom_metadata;
TABLE_NAME
COLUMN_NAME
EMITTER
OWNER2.EQUIPMENTPOINT(EQUIP_X, EQUIP_Y)
Arghhh!!!
Anyone else encounter a similar problem?
I know that I have to be careful regarding owner.packager.function naming convention
I have followed the oracle examples from here
http://www.oracle.com/technology/obe/obe10gdb/content/spatial/files/add_metadata_fi.sql
are they broken? Is this a bug ?

Function based indexes on CLOB storage

On a 10gR2 database, with schema-less CLOB storage for an XMLType column:
(1) Can a function based index include a wildcard in the namespace ? Or do I need a new function based index for each specific namespace ?
(2) I must create a new function based index for each different element that I want an indexed search on ?
(3) What limit is there on the number of function based indexes per table ?
(4) I believe XQuery can include a wildcard for namespaces, but XPath 1.x can't. Can I create a function based index using XQuery, rather than XPath ?
Documents conforming to different versions of an XML schema will be present (schema versioning), but I want to search across all documents irrespective of a specific namespace - e.g. "Find any document with reference = 'some Value' , and amount = 1000".
CLOB storage is proposed, due to the need to handle documents from multiple versions of an XML schema. The knowledge of the XSD is not known at development time, but is user definable, and it must be possible to change the structure without system down time. Structured storage is not suitable, due to Oracle's requirement for downtime if the schema changes (CopyEvolve drops/recreates tables), and Oracle doesn't support schema collections, so you can't bind an XML column to multiple schemas.
Here is some sample code of what I'm trying to do:
create table BulkTest
ID NUMBER(10) not null primary key,
USERFIELDS XMLTYPE
create sequence S_BulkTest;
--Document conforming to version 1 of schema
INSERT INTO BulkTest(id, Userfields) VALUES
(S_BulkTest.Nextval,
'<?xml version="1.0" encoding="utf-8" ?>
<mt395 xmlns="urn:incident:mt395-1">
     <reference>FH12345678</reference>
     <relatedReference>FH23456789</relatedReference>
     <queries>Here is some query text.</queries>
     <narrative>Here is some narrative text.</narrative>
     <relatedMessageType>300</relatedMessageType>
     <relatedMessageDate>2005-03-29</relatedMessageDate>
     <direction>R</direction>
     <sessionNumber>1234</sessionNumber>
     <isn>123456</isn>
     <relatedMessageDescription>This is the deal where I bought USD 1 million for GBP at 1.76.</relatedMessageDescription>
     <otherParty>232332</otherParty>
</mt395>'
--Document conforming to version 2 of schema
INSERT INTO BulkTest(id, Userfields) VALUES
(S_BulkTest.Nextval,
'<?xml version="1.0" encoding="utf-8" ?>
<mt395 xmlns="urn:incident:mt395-2">
     <guid>0f9a08f6-b052-4693-baba-8f7dc881e7e8</guid>
     <reference>333333</reference>
     <queries>Another query</queries>
     <narrative>Some narrative</narrative>
     <direction>R</direction>
     <sessionNumber>1234</sessionNumber>
     <isn>223456</isn>
</mt395>'
--It seems I need to create a new index for each field I want to search on
create index iBulkTest_REFERENCE
on BulkTest
(extractValue(UserFields,'/mt395/reference', 'xmlns="urn:incident:mt395-1"'));
--And that a new index is required for each specifc namespace that is present
--Can't we include a wildcard in the namespace ?
create index iBulkTest_REFERENCE_2
on BulkTest
(extractValue(UserFields,'/mt395/reference', 'xmlns="urn:incident:mt395-2"'));
--If I want to query, I have to explicitly specify each namespace.
--Can't I specify a wildcard ?
--This will make it "fun" querying across namespaces!
select
id,
extractValue(UserFields,'/mt395/reference', 'xmlns="urn:incident:mt395-2"') As Reference,
t.userfields.getclobval() userfields
from bulktest t
WHERE extractValue(UserFields,'/mt395/reference', 'xmlns="urn:incident:mt395-2"') = '333333'

Andy
#1. You do not have scehma versioning here. Your model is totally incorrect. You shoud not change the namespace when versioning the XML Schema. You have 2 different and totally disjoint XML Schemas. The correct was to version, as distinct from evolve an XML Schema is to change the Schema Location Hint associated with your XML...
Eg
INSERT INTO BulkTest(id, Userfields) VALUES
(S_BulkTest.Nextval,
'<?xml version="1.0" encoding="utf-8" ?>
<mt395 xmlns="urn:incident:mt395" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:incident:mt395 mt395-1.xsd">
<reference>FH12345678</reference>
<relatedReference>FH23456789</relatedReference>
<queries>Here is some query text.</queries>
<narrative>Here is some narrative text.</narrative>
<relatedMessageType>300</relatedMessageType>
<relatedMessageDate>2005-03-29</relatedMessageDate>
<direction>R</direction>
<sessionNumber>1234</sessionNumber>
<isn>123456</isn>
<relatedMessageDescription>This is the deal where I bought USD 1 million for GBP at 1.76.</relatedMessageDescription>
<otherParty>232332</otherParty>
</mt395>'
--Document conforming to version 2 of schema
INSERT INTO BulkTest(id, Userfields) VALUES
(S_BulkTest.Nextval,
'<?xml version="1.0" encoding="utf-8" ?>
<mt395 xmlns="urn:incident:mt395 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:incident:mt395 mt395-2.xsd">
<guid>0f9a08f6-b052-4693-baba-8f7dc881e7e8</guid>
<reference>333333</reference>
<queries>Another query</queries>
<narrative>Some narrative</narrative>
<direction>R</direction>
<sessionNumber>1234</sessionNumber>
<isn>223456</isn>
</mt395>'
This is the correct way of versioning an XML Schema. THe namespace stays the same, the SchemaLocationHint in the SchemaLocation tag changes.
Bear in mind that if you use the technique you are currently using you will make any path expressions you need to write absolutely unmaintaining and the processing of them very inefficient.
Some questions to consider
Node 'X' in namespace 'X' is never the same as Node 'X' in namespace 'Y'.
How would you write an Xpath or XQuery that targetted multiple versions, but not all versions ?
What happens if you have other documents that are really in a different namespace ? Using wildcards can you differentiate them..
From the problem you are describing and the terminolgy you are using it looks like you've been an early customer of Yukon. MSFT clearly didn't understand schema versioning in the early beta releases and used the 'change the namespace' schema for modelling schema versioning.
We do have some technology coming down the pipe which can address the issue, regardless of whether or not it is too late for you to correct the versioning scheme you have selected. However I cannot discuss that in a public forum. If you want to learn about these features and are prepared to enter an NDA with Oracle in order to do so please contact me directly. You can do this a number of ways...
Guess my email address @oracle.com
Post your email address here and I'll delete the post as soon as I have it..
Update your OTN Forum profile to include your email address
Open a TAR and post the tar number here. You can then softclose the tar as this is simply a method for me to get your contact info.

How to create function based index for TO_CHAR

i need to create a function based index for the function to_char.when i tried ,i got an error,"only pure function can be indexed".what the error really means, help me in creating the index to reduce my query cost.

It works fine on my database. version 9iR2
create index IDX_TO_CHAR on emp(to_char(hiredate,'YYYY-MM-DD HH24:MI:SS'));
explain plan for
select hiredate from emp where to_char(hiredate,'YYYY-MM-DD HH24:MI:SS')='1981-05-01 00:00:00';
| Id | Operation                   | Name        | Rows | Bytes | Cost (%CPU)|
|   0 | SELECT STATEMENT            |              |     1 |     8 |     2 (50)|
|   1 | TABLE ACCESS BY INDEX ROWID| EMP          |     1 |     8 |     2 (50)|
|* 2 |   INDEX RANGE SCAN          | IDX_TO_CHAR |     1 |       |     2 (50)|
Predicate Information (identified by operation id):
   2 - access(TO_CHAR("EMP"."HIREDATE",'YYYY-MM-DD HH24:MI:SS')='1981-05-01 00
              :00:00')Yours seem like a tuning issue, so why not give us your sql and execution plan and so on.
maybe there is other ways to tune your sql than creating a function based index?

Why Segment shrink is not supported for tables with function-based indexes

As we all know , Segment shrink is not supported for tables with function-based indexes.
But i'm very confused .
Why Segment shrink is not supported for tables with function-based indexes ?? what's its essential?

Creating a function based index creates a hidden virtual column (you'll see it if you query user_tab_cols) and once you index a virtual column you can no longer shrink the table:orcl> create table t1(c1 number,c2 as (c1 * 2)) segment creation immediate;
Table created.
orcl> alter table t1 enable row movement;
Table altered.
orcl>
orcl> alter table t1 shrink space;
Table altered.
orcl> create index i2 on t1(c2);
Index created.
orcl> alter table t1 shrink space;
alter table t1 shrink space
ERROR at line 1:
ORA-10631: SHRINK clause should not be specified for this object
orcl>so the issue is not with function based indexes per se, it is a level beneath that. Perhaps because the virtual column has no physical existance, when the row is moved there is no reason for Oracle to realize that an index needs updating? I haven't attempted to reverse engineer this, I would be interested to know if anyone else has.

Function-based index with OR in the wher-clause

We have some problems with functin-based indexes and
the or-condition in a where-clause.
--We use Oracle 8i (8.1.7)
create table TPERSON(ID number(10),NAME varchar2(20),...);
create index I_NORMAL_TPERSON_NAME on TPERSON(NAME);
create index I_FUNCTION_TPERSON_NAME on TPERSON(UPPER(NAME));
The following two statements run very fast on a large table
and the execution-plan asure the usage of the indexes
(-while the session is appropriate configured and the table is analyzed):
1)     select count(ID) FROM TPERSON where upper(NAME) like 'MIL%';
2)     select count(ID) from TPERSON where NAME like 'Mil%' or (3=5);
In particular we see that a normal index is used while the where-clause contains
an OR-CONDITION.
But if we try the similarly select-statement
3)     select count(ID) FROM TPERSON where upper(NAME) like 'MIL%' or (3=5);
the CBO will not use the function-index I_FUNCTION_TPERSON_NAME and we have a full table scan in the execution-plan.
(This behavior we only expect with views but not with indexes.)
We ask for an advice like a hint, which enable the CBO-usage
of function-based indexes in connection with OR.
This problem seems to be artificial because it contains this dummy logic:
     or (3=5).
This steams from an prepared statement, where this kind of boolean
flag reduce the amount of different select-statements needed for
covering the hole business-logic, while using bind-variables for the
concrete query-parameters.
A more realistic (still boild down) version of our select-statement is:
select * FROM TPERSON
where (upper(NAME) like 'MIL%' or (NAME is null))
and (upper(FIRSTNAME) like 'MICH% or (FIRSTNAME is null))
and ...;
thank you for time..
email: [email protected]

In the realistic statement you write :
select * FROM TPERSON
where (upper(NAME) like 'MIL%' or (NAME is null))
and (upper(FIRSTNAME) like 'MICH% or (FIRSTNAME is null))
and ...;
as far as i know, NULL values are not indexed, "or (NAME is NULL)" have to generate a full table scan.
HTH
We have some problems with functin-based indexes and
the or-condition in a where-clause.
--We use Oracle 8i (8.1.7)
create table TPERSON(ID number(10),NAME varchar2(20),...);
create index I_NORMAL_TPERSON_NAME on TPERSON(NAME);
create index I_FUNCTION_TPERSON_NAME on TPERSON(UPPER(NAME));
The following two statements run very fast on a large table
and the execution-plan asure the usage of the indexes
(-while the session is appropriate configured and the table is analyzed):
1)     select count(ID) FROM TPERSON where upper(NAME) like 'MIL%';
2)     select count(ID) from TPERSON where NAME like 'Mil%' or (3=5);
In particular we see that a normal index is used while the where-clause contains
an OR-CONDITION.
But if we try the similarly select-statement
3)     select count(ID) FROM TPERSON where upper(NAME) like 'MIL%' or (3=5);
the CBO will not use the function-index I_FUNCTION_TPERSON_NAME and we have a full table scan in the execution-plan.
(This behavior we only expect with views but not with indexes.)
We ask for an advice like a hint, which enable the CBO-usage
of function-based indexes in connection with OR.
This problem seems to be artificial because it contains this dummy logic:
     or (3=5).
This steams from an prepared statement, where this kind of boolean
flag reduce the amount of different select-statements needed for
covering the hole business-logic, while using bind-variables for the
concrete query-parameters.
A more realistic (still boild down) version of our select-statement is:
select * FROM TPERSON
where (upper(NAME) like 'MIL%' or (NAME is null))
and (upper(FIRSTNAME) like 'MICH% or (FIRSTNAME is null))
and ...;
thank you for time..
email: [email protected]

Creation of function based index using escape

Hello,
I have the following SQL, sometimes performing bad:
SELECT DISTINCT UPPER(A.PROCESSIDCODE), UPPER(A.RULENAME), CHARSET
FROM XIB_DETECT A, XIB_PROCESSIDPROPERTIES B, XIB_RULES C
WHERE ( A.KEY1 = :P1 OR ( :P1 like REPLACE(REPLACE(REPLACE(REPLACE(KEY1,'%', '\%'),'_', '\_'),'?', '_'),'*','%') escape '\' AND A.REGFLAGS1 = 'Y') OR A.KEY1 = '*' AND A.REGFLAGS1 = 'Y')
AND (A.KEY2 = :P2 OR ( :P2 like REPLACE(REPLACE(REPLACE(REPLACE(KEY2,'%', '\%'),'_', '\_'),'?', '_'),'*','%') escape '\' AND A.REGFLAGS2 = 'Y') OR (A.KEY2 IS NULL AND A.REGFLAGS2 IS NULL ) )
AND (A.KEY3 = :P3 OR ( :P3 like REPLACE(REPLACE(REPLACE(REPLACE(KEY3,'%', '\%'),'_', '\_'),'?', '_'),'*','%') escape '\' AND A.REGFLAGS3 = 'Y') OR (A.KEY3 IS NULL AND A.REGFLAGS3 IS NULL ) )
AND (A.KEY4 = :P4 OR ( :P4 like REPLACE(REPLACE(REPLACE(REPLACE(KEY4,'%', '\%'),'_', '\_'),'?', '_'),'*','%') escape '\' AND A.REGFLAGS4 = 'Y') OR (A.KEY4 IS NULL AND A.REGFLAGS4 IS NULL ) )
AND (A.KEY5 = :P5 OR ( :P5 like REPLACE(REPLACE(REPLACE(REPLACE(KEY5,'%', '\%'),'_', '\_'),'?', '_'),'*','%') escape '\' AND A.REGFLAGS5 = 'Y') OR (A.KEY5 IS NULL AND A.REGFLAGS5 IS NULL ) )
AND (A.KEY6 IS NULL OR A.KEY6 = '*' AND REGFLAGS6 = 'Y')
AND (A.KEY7 IS NULL OR A.KEY7 = '*' AND REGFLAGS7 = 'Y')
AND (A.KEY8 IS NULL OR A.KEY8 = '*' AND REGFLAGS8 = 'Y')
AND (A.KEY9 IS NULL OR A.KEY9 = '*' AND REGFLAGS9 = 'Y')
AND (A.KEY10 IS NULL OR A.KEY10 = '*' AND REGFLAGS10 = 'Y')
AND ( ( A.PROCESSIDCODE IS NOT NULL AND UPPER(A.PROCESSIDCODE) = UPPER(B.PROCESSIDCODE) AND A.XLEVEL = B.XLEVEL AND B.ACTIVEFLAG = 'Y' )
OR ( A.RULENAME IS NOT NULL AND UPPER(A.RULENAME) = UPPER(C.RULENAME) AND A.XLEVEL = C.XLEVEL AND C.ACTIVEFLAG = 'Y' ) );
Now I want to create a function based index on the key1 column:
CREATE INDEX xib_detect_ix ON xib_detect (REPLACE(REPLACE(REPLACE(REPLACE(KEY1,'%', '\%'),'_', '\_'),'?', '_'),'*','%') escape '\') TABLESPACE ... ONLINE;
However, this is not working with "escape" '\', throwing: ORA-00907: missing right parenthesis
Any idea how to create an index on this construct with "escape"?
Database version is 10.2.0.3.
Thanks a lot.
Regards
Oliver

Hi,
You can get the "missing right parenthesis" error for many different syntax errors.
In this case, you really are missing a right parenthesis. Your statement has 5 left '('s, but only 4 right ')'s. It's easy to see this if you format your code:
CREATE INDEX xib_detect_ix
ON xib_detect ( REPLACE ( REPLACE ( REPLACE ( REPLACE ( KEY1
escape '\'
ESCAPE is an option that you can use with the LIKE operator. It gives you a mechanism for cancelling the special meaning of symbols like '%'. You're not using the LIKE operator to create the index. You're only using REPLACE, and no characters have any special meaning in REPLACE, so there's no way (or reason) to escape them. Use ESCAPE in queries that use LIKE, when appropriate.

Function-Based Indexes for 8.1.6 SE and 9iAS

I have installed the 9iAS Portal into a 8.1.6 SE database, and I cannot get the Function-Based Index feature to turn on. I have set QUERY_REWRITE_INTEGRITY=trusted, QUERY_REWRITE_ENABLED=true and COMPATIBLE="8.1.0.0.0". The feature will still not enable.
I have 2 questions:
1. Is there anything else I can do to turn this feature on.
2. If not, do I have to upgrade to 8.1.7 or to 8.1.* Enterprise Edition to make use of this feature.

Could you give the statement for the index you have used, the query you try to do and a description of columns and datatypes of the table? How do you know/check that is doesn't work? Execution plan, errors?...

Function based index Issue

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