Bind variables and function based index
- From: "Kumar Madduri" <ksmadduri@xxxxxxxxx>
- To: oracle-l@xxxxxxxxxxxxx
- Date: Wed, 7 May 2008 21:56:56 -0700
Hi List,
In continuation with my earlier post
This is the query. Couple of things I noticed about this is that this query
does not use the Function based index created on suggested_vendor_name and
also the explain plan repeats itslef (it does the same steps twice).
Attached is the explain plan so that you see what I mean.
On the other hand if I replace these bind variables with actual values, it
does use the index and no repeatition (in explain plan)
SELECT
RH.SEGMENT1 REQUISITION_NUMBER,
XXDL_REQ_WEB_INQUIRY.DECODE_PERSON_NAME(RH.PREPARER_ID) ORIGINATOR_NAME,
RL.SUGGESTED_VENDOR_NAME, RH.CREATION_DATE, RH.AUTHORIZATION_STATUS,
DECODE(NVL(PH.PO_HEADER_ID,'1'),'1',' ',NVL(PH.AUTHORIZATION_STATUS,
'INCOMPLETE')) PO_STATUS
FROM
PO.PO_REQUISITION_LINES_ALL RL, PO.PO_REQUISITION_HEADERS_ALL RH,
PO.PO_REQ_DISTRIBUTIONS_ALL RD, PO.PO_DISTRIBUTIONS_ALL PD,
PO.PO_HEADERS_ALL PH, MTL_CATEGORIES MC WHERE 1=1 AND
UPPER(RL.SUGGESTED_VENDOR_NAME) LIKE UPPER(:B7 || '%') AND
RH.REQUISITION_HEADER_ID = RL.REQUISITION_HEADER_ID+0 AND
RL.REQUISITION_LINE_ID = RD.REQUISITION_LINE_ID AND RD.DISTRIBUTION_ID =
PD.REQ_DISTRIBUTION_ID(+) AND RD.EXPENDITURE_TYPE = NVL(:B6 ,
RD.EXPENDITURE_TYPE) AND PD.PO_HEADER_ID = PH.PO_HEADER_ID(+) AND
RH.CREATION_DATE BETWEEN :B5 AND :B4 AND RH.AUTHORIZATION_STATUS=DECODE(:B3
,'1',RH.AUTHORIZATION_STATUS,:B3 ) AND RL.CATEGORY_ID = MC.CATEGORY_ID AND
MC.SEGMENT1||'' = NVL(:B2 ,MC.SEGMENT1) AND MC.SEGMENT2||'' = NVL(:B1 ,
MC.SEGMENT2) AND ((MC.ATTRIBUTE9 = 'Y') OR (RH.PREPARER_ID =
FND_GLOBAL.EMPLOYEE_ID) OR
(XXDL_REQ_WEB_INQUIRY.ISAPPROVER(RH.REQUISITION_HEADER_ID,
FND_GLOBAL.EMPLOYEE_ID) = 'Y')) ORDER BY RH.CREATION_DATE DESC
On Tue, May 6, 2008 at 5:56 PM, Mark Brinsmead <pythianbrinsmead@xxxxxxxxx>
wrote:
> Using bind variables rather than literals can alter the cardinality
> estimates used by the CBO, and that can alter the execution plan.
>
> It might be helpful to provide the actual query, or at least the execution
> plans.
>
>
>
> On Tue, May 6, 2008 at 5:54 PM, Kumar Madduri <ksmadduri@xxxxxxxxx> wrote:
>
> > Hi
> > Is there any restriction with bind variables and function based indexes.
> > I noticed that if I have literals fbi is being used but if I replace that
> > with bind variables then fbi is not used. DB version is 10.2.0.1. You
> > cant seem to force it to use FBI through hints also. As I am investigating
> > this, I thought of posting here to see if there are any known issues or
> > restrictions that prevent function based indexes usage with bind variables.
> > QUERY_REWRITE_INTEGRITY is set to trusted and query_rewrite_enabled is
> > true.
> >
> > thank you
> > - kumar
> >
>
>
>
> --
> Cheers,
> -- Mark Brinsmead
> Senior DBA,
> The Pythian Group
> http://www.pythian.com/blogs
Rows Execution Plan
------- ---------------------------------------------------
0 SELECT STATEMENT MODE: ALL_ROWS
0 SORT (ORDER BY)
0 CONCATENATION
0 FILTER
0 NESTED LOOPS (OUTER)
0 NESTED LOOPS (OUTER)
0 NESTED LOOPS
0 NESTED LOOPS
0 NESTED LOOPS
22 NESTED LOOPS
22 TABLE ACCESS MODE: ANALYZED (FULL) OF
'MTL_CATEGORIES_B' (TABLE)
22 INDEX MODE: ANALYZED (UNIQUE SCAN) OF
'MTL_CATEGORIES_TL_U1' (INDEX (UNIQUE))
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID)
OF 'PO_REQUISITION_LINES_ALL' (TABLE)
1585746 INDEX MODE: ANALYZED (RANGE SCAN) OF
'PO_REQUISITION_LINES_N2' (INDEX)
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_REQUISITION_HEADERS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (UNIQUE SCAN) OF
'PO_REQUISITION_HEADERS_U1' (INDEX (UNIQUE))
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_REQ_DISTRIBUTIONS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (RANGE SCAN) OF
'PO_REQ_DISTRIBUTIONS_N1' (INDEX)
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_DISTRIBUTIONS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (RANGE SCAN) OF
'PO_DISTRIBUTIONS_N2' (INDEX)
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_HEADERS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (UNIQUE SCAN) OF
'PO_HEADERS_U1' (INDEX (UNIQUE))
0 FILTER
0 NESTED LOOPS (OUTER)
0 NESTED LOOPS (OUTER)
0 NESTED LOOPS
0 NESTED LOOPS
0 NESTED LOOPS
0 NESTED LOOPS
0 TABLE ACCESS MODE: ANALYZED (FULL) OF
'MTL_CATEGORIES_B' (TABLE)
0 INDEX MODE: ANALYZED (UNIQUE SCAN) OF
'MTL_CATEGORIES_TL_U1' (INDEX (UNIQUE))
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID)
OF 'PO_REQUISITION_LINES_ALL' (TABLE)
0 INDEX MODE: ANALYZED (RANGE SCAN) OF
'PO_REQUISITION_LINES_N2' (INDEX)
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_REQUISITION_HEADERS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (UNIQUE SCAN) OF
'PO_REQUISITION_HEADERS_U1' (INDEX (UNIQUE))
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_REQ_DISTRIBUTIONS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (RANGE SCAN) OF
'PO_REQ_DISTRIBUTIONS_N1' (INDEX)
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_DISTRIBUTIONS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (RANGE SCAN) OF
'PO_DISTRIBUTIONS_N2' (INDEX)
0 TABLE ACCESS MODE: ANALYZED (BY INDEX ROWID) OF
'PO_HEADERS_ALL' (TABLE)
0 INDEX MODE: ANALYZED (UNIQUE SCAN) OF
'PO_HEADERS_U1' (INDEX (UNIQUE))
SELECT STATEMENT---Cost = 52
SORT-UNIQUE--
NESTED LOOPS-OUTER--
NESTED LOOPS-OUTER--
NESTED LOOPS---
NESTED LOOPS---
NESTED LOOPS---
NESTED LOOPS---
TABLE ACCESS-FULL-MTL_CATEGORIES_B-
INDEX-UNIQUE SCAN-MTL_CATEGORIES_TL_U1-
TABLE ACCESS-BY INDEX ROWID-PO_REQUISITION_LINES_ALL-
INDEX-RANGE SCAN-XXDL_PO_REQUISITION_LINES_F2-
TABLE ACCESS-BY INDEX ROWID-PO_REQ_DISTRIBUTIONS_ALL-
INDEX-RANGE SCAN-PO_REQ_DISTRIBUTIONS_N1-
TABLE ACCESS-BY INDEX ROWID-PO_REQUISITION_HEADERS_ALL-
INDEX-UNIQUE SCAN-PO_REQUISITION_HEADERS_U1-
TABLE ACCESS-BY INDEX ROWID-PO_DISTRIBUTIONS_ALL-
INDEX-RANGE SCAN-PO_DISTRIBUTIONS_N2-
TABLE ACCESS-BY INDEX ROWID-PO_HEADERS_ALL-
INDEX-UNIQUE SCAN-PO_HEADERS_U1-
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