Query Rewrite (QSM-01263) and Views in Execution Plan

Hello!
I created a query rewrite enabled materialized view from a query, which contains only tables (no views). Query rewrite didn't work, so i checked the query with dbms_mview.explan_rewrite, which told my that my query contains references to views or dictionary tables. I checked my query again, but there are only tables, no views, no dictionary tables.
When I look in the execution plan of my query I see that the query optimizer generates views, I guess from my subquery (?). "A view definition was processed, either from a stored view...or as defined by steps...".
I suppose that's the reason why my query rewrite doesn't work. All my other mat views are working fine, so the usual parameters (query_rewrite_enabled, integrity, etc.) are set correctly.
Do you have any ideas how to get my query rewrite enabled work?
Thanks!

Modifying the query (potentially with hints) so that Oracle doesn't do the view transformation would be one option.

Similar Messages

Query rewrites with Nested materialized views with different aggregations

Platform used : Oracle 11g.
Here is a simple fact table (with measures m1,m2) and dimensions (a) Location (b) Calendar and (c) Product. The business problem is that aggregation operator for measure m1,m2 are different along location dimension and Calendar dimension. The intention is to preaggregate the measures for a product along the calendar dimension and Location dimension and store it as materialized views.
The direct option is to define a materialized view with Inline queries (Because of the different aggrergation operator, it is not possible to write a query without Inline query). http://download-uk.oracle.com/docs/cd/B28359_01/server.111/b28313/qradv.htm#BABEAJBF documents the limitations that it works only for 'Text match' and 'Equivalent queries' and that is too limiting.
So decided to have nested materialized view, with first view having just joins(my_dim_mvw_joins), the second view having aggregations along Calendar dimension (my_dim_mvw_calendar) and third view having aggregations along the Location dimension(my_dim_mvw_location). Obviously I do not want the query I fire to know about materialized views and I fire it against the fact table. I see that for the fired query (Which needs aggregations along both Calendar and Location), is rewritten with just second materialized view but not the third. (Had set QUERY_REWRITE_INTEGRITY as TRUSTED) .
Wanted to know whether there are limitations on Query Writes with nested materialized views? Thanks
(Have given a simple testable example below. Pls ignore the values given in 'CALENDAR_IDs', 'PRODUCT_IDs' etc as they are the same for all the queries)
-- Calendar hierarchy table
CREATE TABLE CALENDAR_HIERARCHY_TREE
(     "CALENDAR_ID" NUMBER(5,0) NOT NULL ENABLE,
"HIERARCHY1_ID" NUMBER(5,0),
"HIERARCHY2_ID" NUMBER(5,0),
"HIERARCHY3_ID" NUMBER(5,0),
"HIERARCHY4_ID" NUMBER(5,0),
CONSTRAINT "CALENDAR_HIERARCHY_TREE_PK" PRIMARY KEY ("CALENDAR_ID")
-- Location hierarchy table
CREATE TABLE LOCATION_HIERARCHY_TREE
(     "LOCATION_ID" NUMBER(3,0) NOT NULL ENABLE,
"HIERARCHY1_ID" NUMBER(3,0),
"HIERARCHY2_ID" NUMBER(3,0),
"HIERARCHY3_ID" NUMBER(3,0),
"HIERARCHY4_ID" NUMBER(3,0),
CONSTRAINT "LOCATION_HIERARCHY_TREE_PK" PRIMARY KEY ("LOCATION_ID")
-- Product hierarchy table
CREATE TABLE PRODUCT_HIERARCHY_TREE
(     "PRODUCT_ID" NUMBER(3,0) NOT NULL ENABLE,
     "HIERARCHY1_ID" NUMBER(3,0),
     "HIERARCHY2_ID" NUMBER(3,0),
     "HIERARCHY3_ID" NUMBER(3,0),
     "HIERARCHY4_ID" NUMBER(3,0),
     "HIERARCHY5_ID" NUMBER(3,0),
     "HIERARCHY6_ID" NUMBER(3,0),
     CONSTRAINT "PRODUCT_HIERARCHY_TREE_PK" PRIMARY KEY ("PRODUCT_ID")
-- Fact table
CREATE TABLE RETAILER_SALES_TBL
(     "PRODUCT_ID" NUMBER,
"PRODUCT_KEY" VARCHAR2(50 BYTE),
"PLAN_ID" NUMBER,
"PLAN_PERIOD_ID" NUMBER,
"PERIOD_ID" NUMBER(5,0),
"M1" NUMBER,
"M2" NUMBER,
"M3" NUMBER,
"M4" NUMBER,
"M5" NUMBER,
"M6" NUMBER,
"M7" NUMBER,
"M8" NUMBER,
"LOCATION_ID" NUMBER(3,0),
"M9" NUMBER,
CONSTRAINT "RETAILER_SALES_TBL_LOCATI_FK1" FOREIGN KEY ("LOCATION_ID")
REFERENCES LOCATION_HIERARCHY_TREE ("LOCATION_ID") ENABLE,
CONSTRAINT "RETAILER_SALES_TBL_PRODUC_FK1" FOREIGN KEY ("PRODUCT_ID")
REFERENCES PRODUCT_HIERARCHY_TREE ("PRODUCT_ID") ENABLE,
CONSTRAINT "RETAILER_SALES_TBL_CALEND_FK1" FOREIGN KEY ("PERIOD_ID")
REFERENCES CALENDAR_HIERARCHY_TREE ("CALENDAR_ID") ENABLE
-- Location dimension definition to promote query rewrite
create DIMENSION LOCATION_DIM
LEVEL CHAIN IS LOCATION_HIERARCHY_TREE.HIERARCHY1_ID
LEVEL CONSUMER_SEGMENT IS LOCATION_HIERARCHY_TREE.HIERARCHY3_ID
LEVEL STORE IS LOCATION_HIERARCHY_TREE.LOCATION_ID
LEVEL TRADING_AREA IS LOCATION_HIERARCHY_TREE.HIERARCHY2_ID
HIERARCHY PROD_ROLLUP (
STORE CHILD OF
CONSUMER_SEGMENT CHILD OF
TRADING_AREA CHILD OF
CHAIN
-- Calendar dimension definition
create DIMENSION CALENDAR_DIM
LEVEL MONTH IS CALENDAR_HIERARCHY_TREE.HIERARCHY3_ID
LEVEL QUARTER IS CALENDAR_HIERARCHY_TREE.HIERARCHY2_ID
LEVEL WEEK IS CALENDAR_HIERARCHY_TREE.CALENDAR_ID
LEVEL YEAR IS CALENDAR_HIERARCHY_TREE.HIERARCHY1_ID
HIERARCHY CALENDAR_ROLLUP (
WEEK CHILD OF
MONTH CHILD OF
QUARTER CHILD OF
YEAR
-- Materialized view with just joins needed for other views
CREATE MATERIALIZED VIEW my_dim_mvw_joins build immediate refresh complete enable query rewrite as
select product_id, lht.HIERARCHY1_ID, lht.HIERARCHY2_ID, lht.HIERARCHY3_ID, lht.location_id, cht.HIERARCHY1_ID year,
cht.HIERARCHY2_ID quarter, cht.HIERARCHY3_ID month, cht.calendar_id week, m1, m3, m7, m9
from retailer_sales_tbl RS, calendar_hierarchy_tree cht, location_hierarchy_tree lht
WHERE RS.period_id = cht.CALENDAR_ID
and RS.location_id = lht.location_id
and cht.CALENDAR_ID in (10,236,237,238,239,608,609,610,611,612,613,614,615,616,617,618,619,1426,1427,1428,1429,1430,1431,1432,1433,1434,1435,1436,1437,1438,1439,1440,1441,1442,1443,1444,1445,1446,1447,1448,1449,1450,1451,1452,1453,1454,1455,1456,1457,1458,1459,1460,1461,1462,1463,1464,1465,1466,1467,1468,1469,1470,1471,1472,1473,1474,1475,1476,1477)
AND product_id IN (5, 6, 7, 8, 11, 12, 13, 14, 17, 18, 19, 20)
AND lht.location_id IN (2, 3, 11, 12, 13, 14, 15, 4, 16, 17, 18, 19, 20)
-- Materialized view which aggregate along calendar dimension
CREATE MATERIALIZED VIEW my_dim_mvw_calendar build immediate refresh complete enable query rewrite as
select product_id, HIERARCHY1_ID , HIERARCHY2_ID , HIERARCHY3_ID ,location_id, year, quarter, month, week,
sum(m1) m1_total, sum(m3) m3_total, sum(m7) m7_total, sum(m9) m9_total,
GROUPING_ID(product_id, location_id, year, quarter, month, week) dim_mvw_gid
from my_dim_mvw_joins
GROUP BY product_id, HIERARCHY1_ID , HIERARCHY2_ID , HIERARCHY3_ID , location_id,
rollup (year, quarter, month, week);
-- Materialized view which aggregate along Location dimension
CREATE MATERIALIZED VIEW my_dim_mvw_location build immediate refresh complete enable query rewrite as
select product_id, year, quarter, month, week, HIERARCHY1_ID, HIERARCHY2_ID, HIERARCHY3_ID, location_id,
sum(m1_total) m1_total_1, sum(m3_total) m3_total_1, sum(m7_total) m7_total_1, sum(m9_total) m9_total_1,
GROUPING_ID(product_id, HIERARCHY1_ID, HIERARCHY2_ID, HIERARCHY3_ID, location_id, year, quarter, month, week) dim_mvw_gid
from my_dim_mvw_calendar
GROUP BY product_id, year, quarter, month, week,
rollup (HIERARCHY1_ID, HIERARCHY2_ID, HIERARCHY3_ID, location_id)
-- SQL Query Fired (for simplicity have used SUM as aggregation operator for both, but they will be different)
select product_id, year, HIERARCHY1_ID, HIERARCHY2_ID,
sum(m1_total) m1_total_1, sum(m3_total) m3_total_1, sum(m7_total) m7_total_1, sum(m9_total) m9_total_1
from
select product_id, HIERARCHY1_ID , HIERARCHY2_ID , year,
sum(m1) m1_total, sum(m3) m3_total, sum(m7) m7_total, sum(m9) m9_total
from
select product_id, lht.HIERARCHY1_ID , lht.HIERARCHY2_ID , lht.HIERARCHY3_ID ,lht.location_id, cht.HIERARCHY1_ID year, cht.HIERARCHY2_ID quarter, cht.HIERARCHY3_ID month, cht.calendar_id week,m1,m3,m7,m9
from
retailer_sales_tbl RS, calendar_hierarchy_tree cht, location_hierarchy_tree lht
WHERE RS.period_id = cht.CALENDAR_ID
and RS.location_id = lht.location_id
and cht.CALENDAR_ID in (10,236,237,238,239,608,609,610,611,612,613,614,615,616,617,618,619,1426,1427,1428,1429,1430,1431,1432,1433,1434,1435,1436,1437,1438,1439,1440,1441,1442,1443,1444,1445,1446,1447,1448,1449,1450,1451,1452,1453,1454,1455,1456,1457,1458,1459,1460,1461,1462,1463,1464,1465,1466,1467,1468,1469,1470,1471,1472,1473,1474,1475,1476,1477)
AND product_id IN (5, 6, 7, 8, 11, 12, 13, 14, 17, 18, 19, 20)
AND lht.location_id IN (2, 3, 11, 12, 13, 14, 15, 4, 16, 17, 18, 19, 20)
GROUP BY product_id, HIERARCHY1_ID , HIERARCHY2_ID , HIERARCHY3_ID , location_id, year
) sales_time
GROUP BY product_id, year,HIERARCHY1_ID, HIERARCHY2_ID
This Query rewrites only with my_dim_mvw_calendar. (as saw in Query Plan and EXPLAIN_MVIEW). But we would like it to use my_dim_mvw_location as that has aggregations for both dimensions.

blackhole001 wrote:
Hi all,
I'm trying to make my programmer's life easier by creating a database view for them to query the data, so they don't have to worry about joining tables. This sounds like a pretty horrible idea. I say this because you will eventually end up with programmers that know nothing about your data model and how to properly interact with it.
Additionally, what you will get is a developer that takes one of your views and see's that of the 20 columns in it, it has 4 that he needs. If all those 4 columns comes from a simple 2 table join, but the view has 8 tables, you're wasting a tonne of resources by using the view (and heaven forbid they have to join that view to another view to get 4 of the 20 columns from that other view as well).
Ideally you'd write stored routines that satisfy exactly what is required (if you are the database resource and these other programmers are java, .net, etc... based) and the front end developers would call those routines customized for an exact purpose.
Creating views is not bad, but it's by no means a proper solution to having developers not learn or understand SQL and/or the data model.

Query Rewrite with regular database Views

Hi all,
I'm trying to make my programmer's life easier by creating a database view for them to query the data, so they don't have to worry about joining tables. However, query rewrite doesn't work no matter how I define the MV and View. Here's an example:
I've Sales tables with columns: PDate, CustCode, Amount
and Customer table with columns: CustCode, CustDesc
I create a view SALES_V with columns: PDate, CustCode, CustDesc, Amount by joining Sales table with Customer table as follows:
create or replace view SALES_V as
select PDate, c.CustCode, c.CustDesc, Amount
from Sales s
join Customer c on (s.CustCode=c.CustCode);
For the sake of speed, I create a materialized view SALES_TOT_MV with columns: PDate, Amount with the following SQL:
create materialized view SALES_TOT_MV
enable query rewrite
as select PDate, sum(Amount) Amount from Sales
group by PDate;
When I run the following query, I expect it to be rewritten to make use of SALES_TOT_MV:
select PDate, sum(Amount) from SALES_V
group by PDate;
However, explain plan always tell me it's using SALES table, not the SALES_TOT_MV.
Can somebody tell me it's a limitation of Oracle optimizer or I'm just missing something for this?
Thanks in advance!!
- Andrew
Edited by: blackhole001 on Jan 28, 2010 12:34 PM

blackhole001 wrote:
Hi all,
I'm trying to make my programmer's life easier by creating a database view for them to query the data, so they don't have to worry about joining tables. This sounds like a pretty horrible idea. I say this because you will eventually end up with programmers that know nothing about your data model and how to properly interact with it.
Additionally, what you will get is a developer that takes one of your views and see's that of the 20 columns in it, it has 4 that he needs. If all those 4 columns comes from a simple 2 table join, but the view has 8 tables, you're wasting a tonne of resources by using the view (and heaven forbid they have to join that view to another view to get 4 of the 20 columns from that other view as well).
Ideally you'd write stored routines that satisfy exactly what is required (if you are the database resource and these other programmers are java, .net, etc... based) and the front end developers would call those routines customized for an exact purpose.
Creating views is not bad, but it's by no means a proper solution to having developers not learn or understand SQL and/or the data model.

Query Rewrite to Utilize Materialized Views on a Remote Database

We have our materilized views stored at a remote database. Is there a way to utilize query rewrite to rewrite the queries issued on the local database such that queries will refer the materialized views at a remote db?
From the documentation, I already know that the base tables for MVs and MVs should eside in the same instance or the query should be submitted on the instance where MVs reside if base tables are residing in a different remote DB to benefit from query rewrite.
My aim is to utilize query rewrite to reduce the workload on a primary database by passing queries that can be rewritten to use MVs on a remote DB.
Thanks for the guidance,

My aim is to utilize query rewrite to reduce the workload on a primary database by passing queries that can be rewritten to use MVs on a remote DB. If you know that MVs are not stale or acceptable of staled data and don't see network bandwidth problems (small set of result), You would try accessing MV tables directly on remote db using dblinks.

Very high parse times for query rewrite using cube materialized views

We recently upgraded to version 11.2.0.2 (both AWM and Oracle database server). We are using cube materialized views with query rewrite enabled. Some observations of changes that took place when we rebuilt all the dimensions and cubes in this version:
1. Queries against the base tables take about 35 seconds to parse. Then they execute in a tenth of a second. Even simple queries that just get a sum of the amount from the fact table (which is joined to all the dimensions) takes that long to parse. Once parsed, the queries fly.
2. I noticed that the materialized views used to use grouping sets in the group by clause in version 11.2.0.1, but now they use group by rollup, rollup, rollup...
If we disable query rewrite on the MV or for my session, parse times drop to less than a second. Ideas?

There does appear to be a slow down in parse times between 11.1.0.7 and 11.2. We are still investigating this, but in the meantime here is a way to force the code in 11.2 to generate a GROUPING SETS clause instead of the new ROLLUP syntax.
The trick is to create a dummy hierarchy containing only the leaf level. This is necessary for all dimensions that currently have a single hierarchy. As a simple example I created a dimension, PROD, with three levels, A, B, and C, in a single hierarchy. I then created a one dimensional cube, PC. Here is the SELECT statement for the MV in 11.2. Note the ROLLUP clause in the GROUP BY.
SELECT
GROUPING_ID(T3."CLASS_ID", T3."FAMILY_ID", T3."ITEM_ID") SYS_GID,
(CASE GROUPING_ID(T3."CLASS_ID", T3."FAMILY_ID", T3."ITEM_ID")
   WHEN 3
   THEN TO_CHAR(('A_' || T3."CLASS_ID") )
   WHEN 1
   THEN TO_CHAR(('B_' || T3."FAMILY_ID") )
   ELSE TO_CHAR(('C_' || T3."ITEM_ID") ) END)     "PROD",
T3."CLASS_ID" "D1_PROD_A_ID",
T3."FAMILY_ID" "D1_PROD_B_ID",
T3."ITEM_ID" "D1_PROD_C_ID",
SUM(T2."UNIT_PRICE")     "PRICE",
COUNT(T2."UNIT_PRICE") "COUNT_PRICE",
COUNT(*) "SYS_COUNT"
FROM
GLOBAL."PRICE_AND_COST_FACT" T2,
GLOBAL."PRODUCT_DIM" T3
WHERE
(T3."ITEM_ID" = T2."ITEM_ID")
GROUP BY
(T3."CLASS_ID") ,
ROLLUP ((T3."FAMILY_ID") , (T3."ITEM_ID") )Next I modified the dimension to add a new hierarchy, DUMMY, containing just the leaf level, C. Once I have mapped the new level and re-enabled MVs, I get the following formulation.
SELECT
GROUPING_ID(T3."CLASS_ID", T3."FAMILY_ID", T3."ITEM_ID") SYS_GID,
(CASE GROUPING_ID(T3."CLASS_ID", T3."FAMILY_ID", T3."ITEM_ID")
   WHEN 3
   THEN ('A_' || T3."CLASS_ID")
   WHEN 1
   THEN ('B_' || T3."FAMILY_ID")
   WHEN 0
   THEN ('C_' || T3."ITEM_ID")
   ELSE NULL END) "PROD",
T3."CLASS_ID" "D1_PROD_A_ID",
T3."FAMILY_ID" "D1_PROD_B_ID",
T3."ITEM_ID" "D1_PROD_C_ID",
SUM(T2."UNIT_PRICE")     "PRICE",
COUNT(T2."UNIT_PRICE") "COUNT_PRICE",
COUNT(*) "SYS_COUNT"
FROM
GLOBAL."PRICE_AND_COST_FACT" T2,
GLOBAL."PRODUCT_DIM" T3
WHERE
(T3."ITEM_ID" = T2."ITEM_ID")
GROUP BY
GROUPING SETS ((T3."CLASS_ID") , (T3."FAMILY_ID", T3."CLASS_ID") , (T3."ITEM_ID", T3."FAMILY_ID", T3."CLASS_ID") )This puts things back the way they were in 11.1.0.7 when the GROUPING SETS clause was used in all cases. Note that the two queries are logically equivalent.

How do you view the execution plan of a query?

I want to see if a particular index was used for a specific query....

Becareful. You are in the Forum of OBIEE. It's much more a database question.
You can read an plan with a lot of tool. Toad permit it and I assume that Sql Developer also must give it.
Otherwise, you can use the basic command of Oracle as explain plan :
http://gerardnico.com/wiki/database/oracle/explain_plan
Cheers
Nico

Need query to link parent and child discrete job planned through ascp

Could you help me create a query that will show both the parent and child discrete jobs created through ascp run? I do not need entire query. I need to know the names of tables and understand the links or joins between tables. Then, I shall be able to write the sql on my own.
Thanks

Hi;
Please check below thread which could be helpful for your issue:
http://forums.oracle.com/forums/thread.jspa?messageID=9155702
Regard
Helios

Help with query rewrite and materialized views

Hello everybody,
I'm currently learning how to use Oracle (10G Enterprise) and in particular, Materialized Views.
I seem to have a problem making the optimizer use a materialized view. I have already set the OPTIMIZER_MODE, QUERY_REWRITE_ENABLED and QUERY_REWRITE_INTEGRITY as needed.
I need to create a materialized view for the following query:
Q1:
SELECT PS_SUPPKEY, PS_PARTKEY, PS_SUPPCOST
FROM PARTSUPPLIER E, PART WHERE PS_PARTKEY=P_PARTKEY and (lower(P_COMMENT) LIKE ''_o_a\%'' or lower(P_COMMENT) LIKE ''_o_u\%'')
and PS_SUPPCOST =
(SELECT min( PS_SUPPCOST)
FROM PARTSUPPLIER I
WHERE E.PS_PARTKEY=I.PS_PARTKEY)'
I created it using the following code:
CREATE MATERIALIZED VIEW mv_q1
ENABLE QUERY REWRITE
AS SELECT PS_SUPPKEY, PS_PARTKEY, PS_SUPPCOST
FROM PARTSUPPLIER E JOIN PART ON (PS_PARTKEY=P_PARTKEY)
WHERE lower(P_COMMENT) LIKE '_o_a%' or lower(P_COMMENT) LIKE '_o_u%'
and PS_SUPPCOST=
(SELECT min( PS_SUPPCOST)
FROM PARTSUPPLIER I
WHERE E.PS_PARTKEY=I.PS_PARTKEY);
I have created the statistics using:
execute dbms_stats.gather_table_stats('frandres',' mv_q1');
execute dbms_stats.gather_table_stats('frandres','PARTSUPPLIER');
execute dbms_stats.gather_table_stats('frandres','PART');
Both partsupplier and part are tables and not views.
When executing Q1, the plan does not use the materialized view. Furthermore, when using explain rewrite:
DECLARE
qrytxt VARCHAR2(3000) := 'SELECT PS_SUPPKEY, PS_PARTKEY, PS_SUPPCOST
FROM PARTSUPPLIER E, PART WHERE PS_PARTKEY=P_PARTKEY and (lower(P_COMMENT) LIKE ''_o_a\%'' or lower(P_COMMENT) LIKE ''_o_u\%'')
and PS_SUPPCOST =
(SELECT min( PS_SUPPCOST)
FROM PARTSUPPLIER I
WHERE E.PS_PARTKEY=I.PS_PARTKEY)';
BEGIN
dbms_mview.EXPLAIN_REWRITE
(qrytxt,'MV_Q1','MV_Q1');
END;
I get the following message:
MESSAGE
QSM-01150: query did not rewrite
QSM-01263: query rewrite not possible when query references a dictionary table o
r view
QSM-01219: no suitable materialized view found to rewrite this query
What I can't understand is why it says I am referencing the dictionary or a view?
If I remove the (lower(P_COMMENT) LIKE ''_o_a\%'' or lower(P_COMMENT) LIKE ''_o_u\%'') condition to the query (using the same materialized view), I get the following message from EXPLAIN_REWRITE:
MESSAGE
QSM-01150: query did not rewrite
QSM-01219: no suitable materialized view found to rewrite this query
Which is reasonable.
I don't know if the like condition is messing up my materialized view. Can anyone please help?
Thanks a lot in advance.
Edited by: user12072111 on Oct 29, 2009 9:43 PM

Bingo!
The 10.2.0.3 patch set is supposed to fix this ( [List of bugs fixed (MVs)|http://www.dbatools.net/doc/bug10203.html#MVIEW] )
In particular:
5052568 Query rewrite does not work for SQL with LIKE clause.
Thank you very much for your message!
The downside is that I'm only using Oracle for educational purposes and consequently have no Metalink id, so I can't install the patch. Thanks a lot though!

Spatial vs. materialized views/query rewrite

Dear all,
we are trying to use Spatial (Locator) functionality together with performance optimization using materialized views and query rewrite, and it does not seem to work. Does anybody has experience with this?
The problem in more detail:
* There is a spatial attribut (vom Typ GEOMETRY) in our table;
* we define a materialized view on that table;
* we run a query that could be better answered using the materialized view with query rewrite;
*the optimizer does not choose the plan using the materialized view, query rewrite does not take place;
This happenes, even if neither the materialized view, nor the query contains the spatial attribut.
The explanation given by the procedure DBMS_MVIEW.Explain_Rewrite is:
"QSM-01064 query has a fixed table or view Cause: Query
rewrite is not allowed if query references any fixed tables or views"
We are using Oracle 9R2, Enterprise Edition, with locator. Nevertheless, it would also be interesting, if there is any improvement in 10g?
A more complicated task, using materialized views to optimize spatial operations (e.g., sdo_relate) would also be very interesting, as spatial joins are very expensive operations.
Thanks in advance for any comments, ideas!
Cheers,
Gergely Lukacs

Hi Dan,
thanks for your rapid response!
A simple example is:
alter session set query_rewrite_integrity=trusted;
alter session set query_rewrite_enabled=true;
set serveroutput on;
/* Creating testtable */
CREATE TABLE TESTTABLE (
KEY1 NUMBER (4) NOT NULL,
KEY2 NUMBER (8) NOT NULL,
KEY3 NUMBER (14) NOT NULL,
NAME VARCHAR2 (255),
X NUMBER (9,2),
Y NUMBER (9,2),
ATTR1 VARCHAR2 (2),
ATTR2 VARCHAR2 (30),
ATTR3 VARCHAR2 (80),
ATTR4 NUMBER (7),
ATTR5 NUMBER (4),
ATTR6 NUMBER (5),
ATTR7 VARCHAR2 (40),
ATTR8 VARCHAR2 (40),
CONSTRAINT TESTTABLE_PK
PRIMARY KEY ( KEY1, KEY2, KEY3 ));
/* Creating materialized view */
CREATE MATERIALIZED VIEW TESTTABLE_MV
REFRESH COMPLETE
ENABLE QUERY REWRITE
AS SELECT DISTINCT ATTR7, ATTR8
FROM TESTTABLE;
/* Creating statistics, just to make sure */
execute dbms_stats.gather_table_stats(ownname=> 'TESTSCHEMA', tabname=> 'TESTTABLE', cascade=>TRUE);
execute dbms_stats.gather_table_stats(ownname=> 'TESTSCHEMA', tabname=> 'TESTTABLE_MV', cascade=>TRUE);
/* Explain rewrite procedure */
DECLARE
Rewrite_Array SYS.RewriteArrayType := SYS.RewriteArrayType();
querytxt VARCHAR2(1500) :=
'SELECT COUNT(*) FROM (
SELECT DISTINCT
ATTR8 FROM
TESTTABLE
i NUMBER;
BEGIN
DBMS_MVIEW.Explain_Rewrite(querytxt, 'TESTTABLE_MV', Rewrite_Array);
FOR i IN 1..Rewrite_Array.count
LOOP
DBMS_OUTPUT.PUT_LINE(Rewrite_Array(i).message);
END LOOP;
END;
The message you get is:
QSM-01009 materialized view, string, matched query text
Cause: The query was rewritten using a materialized view, because query text matched the materialized view text.
Action: No action required.
i.e. query rewrite works!
/* Adding geometry column to the testtable -- not to the materialized view, and not to the query! */
ALTER TABLE TESTTABLE
ADD GEOMETRYATTR mdsys.sdo_geometry;
/* Explain rewrite procedure */
DECLARE
Rewrite_Array SYS.RewriteArrayType := SYS.RewriteArrayType();
querytxt VARCHAR2(1500) :=
'SELECT COUNT(*) FROM (
SELECT DISTINCT
ATTR8 FROM
TESTTABLE
i NUMBER;
BEGIN
DBMS_MVIEW.Explain_Rewrite(querytxt, 'TESTTABLE_MV', Rewrite_Array);
FOR i IN 1..Rewrite_Array.count
LOOP
DBMS_OUTPUT.PUT_LINE(Rewrite_Array(i).message);
END LOOP;
END;
The messages you get are:
QSM-01064 query has a fixed table or view
Cause: Query rewrite is not allowed if query references any fixed tables or views.
Action: No action required.
QSM-01019 no suitable materialized view found to rewrite this query
Cause: There doesn't exist any materialized view that can be used to rewrite this query.
Action: Consider creating a new materialized view.
i.e. query rewrite does not work!
If this works, the next issue is to use materialized views for optimizing spatial operations, e.g., a spatial join. I can supply you with an example, if necessary (only makes sense, I think, after the first problem is solved).
Thanks in advance for any ideas, comments!
Cheers,
Gergely

Materialized views on prebuilt tables - query rewrite

Hi Everyone,
I am currently counting on implementing the query rewrite functionality via materialized views to leverage existing aggregated tables.
Goal*: to use aggregate-awareness for our queries
How*: by creating views on existing aggregates loaded via ETL (+CREATE MATERIALIZED VIEW xxx on ON PREBUILT TABLE ENABLE QUERY REWRITE+)
Advantage*: leverage oracle functionalities + render logical model simpler (no aggregates)
Disadvantage*: existing ETL's need to be written as SQL in view creation statement --> aggregation rule exists twice (once on db, once in ETL)
Issue*: Certain ETL's are quite complex via lookups, functions, ... --> might create overy complex SQLs in view creation statements
My question: is there a way around the issue described? (I'm assuming the SQL in the view creation is necessary for oracle to know when an aggregate can be used)
Best practices & shared experiences are welcome as well of course
Kind regards,
Peter

streefpo wrote:
I'm still in the process of testing, but the drops should not be necessary.
Remember: The materialized view is nothing but a definition - the table itself continues to exist as before.
So as long as the definition doesn't change (added column, changed calculation, ...), the materialized view doesn't need to be re-created. (as the data is not maintained by Oracle)Thanks for reminding me but if you find a documented approach I will be waiting because this was the basis of my argument from the beginning.
SQL> select * from v$version ;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
PL/SQL Release 11.2.0.1.0 - Production
CORE     11.2.0.1.0     Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
SQL> desc employees
Name                                                                                            Null?    Type
EMPLOYEE_ID                                                                                     NOT NULL NUMBER(6)
FIRST_NAME                                                                                               VARCHAR2(20)
LAST_NAME                                                                                       NOT NULL VARCHAR2(25)
EMAIL                                                                                           NOT NULL VARCHAR2(25)
PHONE_NUMBER                                                                                             VARCHAR2(20)
HIRE_DATE                                                                                       NOT NULL DATE
JOB_ID                                                                                          NOT NULL VARCHAR2(10)
SALARY                                                                                                   NUMBER(8,2)
COMMISSION_PCT                                                                                           NUMBER(2,2)
MANAGER_ID                                                                                               NUMBER(6)
DEPARTMENT_ID                                                                                            NUMBER(4)
SQL> select count(*) from employees ;
COUNT(*)
       107
SQL> create table mv_table nologging as select department_id, sum(salary) as totalsal from employees group by department_id ;
Table created.
SQL> desc mv_table
Name                                                                                            Null?    Type
DEPARTMENT_ID                                                                                            NUMBER(4)
TOTALSAL                                                                                                 NUMBER
SQL> select count(*) from mv_table ;
COUNT(*)
        12
SQL> create materialized view mv_table on prebuilt table with reduced precision enable query rewrite as select department_id, sum(salary) as totalsal from employees group by department_id ;
Materialized view created.
SQL> select count(*) from mv_table ;
COUNT(*)
        12
SQL> select object_name, object_type from user_objects where object_name = 'MV_TABLE' ;
OBJECT_NAME                                                                                                                      OBJECT_TYPE
MV_TABLE                                                                                                                         TABLE
MV_TABLE                                                                                                                         MATERIALIZED VIEW
SQL> insert into mv_table values (999, 100) ;
insert into mv_table values (999, 100)
ERROR at line 1:
ORA-01732: data manipulation operation not legal on this view
SQL> update mv_table set totalsal = totalsal * 1.1 where department_id = 10 ;
update mv_table set totalsal = totalsal * 1.1 where department_id = 10
ERROR at line 1:
ORA-01732: data manipulation operation not legal on this view
SQL> delete from mv_table where totalsal <= 10000 ;
delete from mv_table where totalsal <= 10000
ERROR at line 1:
ORA-01732: data manipulation operation not legal on this view While investigating for this thread I actually made my own question redundant as the answer became gradually clear:
When using complex ETL's, I just need to make sure the complexity is located in the ETL loading the detailed table, not the aggregate
I'll try to clarify through an example:
- A detailed Table DET_SALES exists with Sales per Day, Store & Product
- An aggregated table AGG_SALES_MM exists with Sales, SalesStore per Month, Store & Product
- An ETL exists to load AGG_SALES_MM where Sales = SUM(Sales) & SalesStore = (SUM(Sales) Across Store)
--> i.e. the SalesStore measure will be derived out of a lookup
- A (Prebuilt) Materialized View will exist with the same column definitions as the ETL
--> to allow query-rewrite to know when to access the table
My concern was how to include the SalesStore in the materialized view definition (--> complex SQL!)
--> I should actually include SalesStore in the DET_SALES table, thus:
- including the 'Across Store' function in the detailed ETL
- rendering my Aggregation ETL into a simple GROUP BY
- rendering my materialized view definition into a simple GROUP BY as wellNot sure how close your example is to your actual problem. Also don't know if you are doing an incremental/complete data load and the data volume.
But the "SalesStore = (SUM(Sales) Across Store)" can be derived from the aggregated MV using analytical function. One can just create a normal view on top of MV for querying. It is hard to believe that aggregating in detail table during ETL load is the best approach but what do I know?

Query rewrite does not happen

Hello all,
let me start by wishing you all the best for the forthcoming year !
And now, the problem
I am trying to create a materialized view so that a few slow reports that run on OBIEE (10g) make use of query rewrite functionality. Unfortunately any attempt that had made was unsuccessful. I though of posting the query that is created by OBIEE and the different materialized views that i have created, so that anyone that had a similar problem before might help me through it. So here it goes ( there is a separate discussion for the other query here ) :
First comes the query that was created by OBIEE when no materialized view existed.
SELECT DISTINCT D1.c5 AS c1,                  D1.c10 AS c2,                       D1.c9 AS c3,                  D1.c6 AS c4,                  D1.c8 AS c5,                  D1.c8 / NULLIF (D1.c6, 0) AS c6,
                  D1.c7 AS c7,                  D1.c7 / NULLIF (D1.c6, 0) AS c8,        D1.c4 AS c9,                  D1.c3 / NULLIF (D1.c1, 0) AS c10,                     D1.c2 / NULLIF (D1.c1, 0) AS c11
    FROM (SELECT SUM (D1.c6) OVER (PARTITION BY D1.c5) AS c1,
                 SUM (D1.c7) OVER (PARTITION BY D1.c5) AS c2,
                 SUM (D1.c8) OVER (PARTITION BY D1.c5) AS c3,
                 SUM (D1.c4) OVER (PARTITION BY D1.c5) AS c4,
                 D1.c5 AS c5,                 D1.c6 AS c6,                 D1.c7 AS c7,                 D1.c8 AS c8,                 D1.c9 AS c9,                 D1.c10 AS c10
            FROM ( SELECT COUNT (CASE D1.c12 WHEN 1 THEN D1.c11 ELSE NULL END)    AS c4,                    D1.c5 AS c5,                           SUM (D1.c13) AS c6,
                         SUM (D1.c14) AS c7,                           SUM (D1.c15) AS c8,               COUNT (DISTINCT D1.c11) AS c9,                           D1.c10 AS c10
                      FROM (SELECT                   /*+ PARALLEL(T16913,8) */
                                  T19403.YEAR_MONTH   AS c5,
                                   T7252.PERCENTAGE AS c10,
                                   T366.BARCODE AS c11,
                                   ROW_NUMBER ()   OVER ( PARTITION BY T19403.YEAR_MONTH,   T366.BARCODE ORDER BY T19403.YEAR_MONTH DESC,   T366.BARCODE DESC) AS c12,
                                   T16913.PHA_QUANTITY AS c13,
                                   T16913.EXEC_COST AS c14,
                                   T16913.EXEC_VALUE AS c15
                              FROM EXECALENDAR_DIM T19403,
                                       DRUG_DIM T366,
                                       PERCENTAGE_DIM T7252,
                                       PRESCDRUG_FACT T16913
                             WHERE (T366.DWHKEY = T16913.DRU_DWHKEY
                                    AND T7252.DWHKEY = T16913.PER_DWHKEY
                                    AND T16913.EXECUTION_DATE =
                                           T19403.CALENDAR_DATE
                                    AND T19403.YEAR_MONTH = '201212')) D1
                  GROUP BY D1.c5, D1.c10) D1) D1
ORDER BY c1, c2
so my first try was that
CREATE MATERIALIZED VIEW PRESCDRUG_FACT_MV BUILD IMMEDIATE REFRESH ON DEMAND ENABLE QUERY REWRITE AS
SELECT /*+ PARALLEL(PRESCDRUG_FACT,8) */
                 EXECALENDAR_DIM.YEAR_MONTH       as YEAR_MONTH
                ,PRESCDRUG_FACT.PER_DWHKEY
                 ,count(*)                            as COUNT_ALL
                 ,COUNT (EXECALENDAR_DIM.YEAR_MONTH) AS c_YEAR_MONTH
                 ,COUNT (DISTINCT PRESCDRUG_FACT.DRUG_CD) DRUG_CODE
                 ,COUNT (DISTINCT PRESCDRUG_FACT.DRUG_BARCODE) BARCODE
                  -- quantities
                 ,SUM (PRESCDRUG_FACT.PHA_QUANTITY) AS PHA_QUANTITY
                 ,SUM (PRESCDRUG_FACT.DOC_QUANTITY) AS DOC_QUANTITY
                 ,SUM (PRESCDRUG_FACT.APR_QUANTITY) AS APR_QUANTITY
                 -- values
                 ,SUM (PRESCDRUG_FACT.EXEC_VALUE)       AS EXEC_VALUE
                 ,SUM (PRESCDRUG_FACT.PUB_VALUE)        AS PUB_VALUE
                 ,SUM (PRESCDRUG_FACT.APR_VALUE) AS APR_VALUE
                 -- costs
                 ,SUM (PRESCDRUG_FACT.EXEC_COST) AS EXEC_COST
                 ,SUM (PRESCDRUG_FACT.PUB_COST) AS PUB_COST
                 ,SUM (PRESCDRUG_FACT.APR_COST) AS APR_COST
   FROM EXECALENDAR_DIM,    PRESCDRUG_FACT
WHERE EXECALENDAR_DIM.CALENDAR_DATE   = PRESCDRUG_FACT.EXECUTION_DATE
       AND EXECALENDAR_DIM.YEAR_MONTH in ( '201212')
   GROUP BY   EXECALENDAR_DIM.YEAR_MONTH ,PRESCDRUG_FACT.PER_DWHKEY
and i got the following messages from DBMS_MVIEW.EXPLAIN_REWRITE
QSM-01150: query did not rewrite
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, EXECALENDAR_DIM, on column, CALENDAR_DATE
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, EXECUTION_DATE
QSM-01082: Joining materialized view, PRESCDRUG_FACT_MV, with table, PRESCDRUG_FACT, not possible
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, DRU_DWHKEY
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, EXEC_VALUE
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, EXEC_COST
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, PHA_QUANTITY
QSM-01155: multi-mv query rewrite not possible when there is a Window Function
QSM-01219: no suitable materialized view found to rewrite this query
My second attempt is the following ( in comparison to the first i have added the DRUG_BARCODE column in the grouping clause
CREATE MATERIALIZED VIEW PRESCDRUG_FACT_MV BUILD IMMEDIATE REFRESH ON DEMAND ENABLE QUERY REWRITE AS
SELECT /*+ PARALLEL(PRESCDRUG_FACT,8) */
                 EXECALENDAR_DIM.YEAR_MONTH       as YEAR_MONTH
                 ,PRESCDRUG_FACT.PER_DWHKEY
              ,PRESCDRUG_FACT.DRUG_BARCODE
                 ,count(*)                                            as COUNT_ALL
                 ,COUNT (EXECALENDAR_DIM.YEAR_MONTH) AS c_YEAR_MONTH
                 ,COUNT (DISTINCT PRESCDRUG_FACT.DRUG_CD) DRUG_CODE
                 ,COUNT (DISTINCT PRESCDRUG_FACT.DRUG_BARCODE) BARCODE
                 ,COUNT (DISTINCT PRESCDRUG_FACT.PRESC_NUMBER) PRESC_NUMBER
                 ,COUNT (DISTINCT PRESCDRUG_FACT.PRESC_ID) PRESC_ID
                  -- quantities
                 ,SUM (PRESCDRUG_FACT.PHA_QUANTITY) AS PHA_QUANTITY
                 ,SUM (PRESCDRUG_FACT.DOC_QUANTITY)        AS DOC_QUANTITY
                 ,SUM (PRESCDRUG_FACT.APR_QUANTITY) AS APR_QUANTITY
                 -- values
                 ,SUM (PRESCDRUG_FACT.EXEC_VALUE)       AS EXEC_VALUE
                 ,SUM (PRESCDRUG_FACT.PUB_VALUE)        AS PUB_VALUE
                 ,SUM (PRESCDRUG_FACT.APR_VALUE) AS APR_VALUE
                 -- costs
                 ,SUM (PRESCDRUG_FACT.EXEC_COST) AS EXEC_COST
                 ,SUM (PRESCDRUG_FACT.PUB_COST) AS PUB_COST
                 ,SUM (PRESCDRUG_FACT.APR_COST) AS APR_COST
    FROM EXECALENDAR_DIM,    PRESCDRUG_FACT
WHERE EXECALENDAR_DIM.CALENDAR_DATE   = PRESCDRUG_FACT.EXECUTION_DATE
       AND EXECALENDAR_DIM.YEAR_MONTH in ( '201212')
   GROUP BY   EXECALENDAR_DIM.YEAR_MONTH ,PRESCDRUG_FACT.PER_DWHKEY,DRUG_BARCODE
and the results of DBMS_MVIEW.EXPLAIN_REWRITE
QSM-01150: query did not rewrite
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, EXECALENDAR_DIM, on column, CALENDAR_DATE
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, EXECUTION_DATE
QSM-01082: Joining materialized view, PRESCDRUG_FACT_MV, with table, PRESCDRUG_FACT, not possible
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, DRU_DWHKEY
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, EXEC_VALUE
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, EXEC_COST
QSM-01102: materialized view, PRESCDRUG_FACT_MV, requires join back to table, PRESCDRUG_FACT, on column, PHA_QUANTITY
QSM-01155: multi-mv query rewrite not possible when there is a Window Function
QSM-01219: no suitable materialized view found to rewrite this query
third try (rolling up the group results)
CREATE MATERIALIZED VIEW PRESCDRUG_FACT_MV BUILD IMMEDIATE REFRESH ON DEMAND ENABLE QUERY REWRITE AS
SELECT /*+ PARALLEL(PRESCDRUG_FACT,8) */
                 EXECALENDAR_DIM.YEAR_MONTH       as YEAR_MONTH
                 ,PRESCDRUG_FACT.PER_DWHKEY
              ,PRESCDRUG_FACT.DRUG_BARCODE
                 ,count(*)                                            as COUNT_ALL
                 ,COUNT (EXECALENDAR_DIM.YEAR_MONTH) AS c_YEAR_MONTH
                 ,COUNT (DISTINCT PRESCDRUG_FACT.DRUG_CD) DRUG_CODE
                 ,COUNT (DISTINCT PRESCDRUG_FACT.DRUG_BARCODE) BARCODE
                 ,COUNT (DISTINCT PRESCDRUG_FACT.PRESC_NUMBER) PRESC_NUMBER
                 ,COUNT (DISTINCT PRESCDRUG_FACT.PRESC_ID) PRESC_ID
                  -- quantities
                 ,SUM (PRESCDRUG_FACT.PHA_QUANTITY) AS PHA_QUANTITY
                 ,SUM (PRESCDRUG_FACT.DOC_QUANTITY)        AS DOC_QUANTITY
                 ,SUM (PRESCDRUG_FACT.APR_QUANTITY) AS APR_QUANTITY
                 -- values
                 ,SUM (PRESCDRUG_FACT.EXEC_VALUE)       AS EXEC_VALUE
                 ,SUM (PRESCDRUG_FACT.PUB_VALUE)        AS PUB_VALUE
                 ,SUM (PRESCDRUG_FACT.APR_VALUE) AS APR_VALUE
                 -- costs
                 ,SUM (PRESCDRUG_FACT.EXEC_COST) AS EXEC_COST
                 ,SUM (PRESCDRUG_FACT.PUB_COST) AS PUB_COST
                 ,SUM (PRESCDRUG_FACT.APR_COST) AS APR_COST
    FROM EXECALENDAR_DIM,    PRESCDRUG_FACT
WHERE EXECALENDAR_DIM.CALENDAR_DATE   = PRESCDRUG_FACT.EXECUTION_DATE
       AND EXECALENDAR_DIM.YEAR_MONTH in ( '201212')
   GROUP BY   EXECALENDAR_DIM.YEAR_MONTH     , rollup (PRESCDRUG_FACT.PER_DWHKEY,    DRUG_BARCODE)
results from DBMS_MVIEW.EXPLAIN_REWRITE
QSM-01150: query did not rewrite
QSM-01295: no suitable grouping_id found in materialized view with grouping sets
QSM-01155: multi-mv query rewrite not possible when there is a Window Function
QSM-01219: no suitable materialized view found to rewrite this query
So, no luck so far. My guess is that it has to do something with the partition clause that appears in the original query.
anyway, if anything cross your minds..
thanks in advance
Theodore

Hello again,
It appeared that, the problem is present only when I try the query in pl/sql developer.
For some reason, even though I set QUERY_REWRITE_INTEGRITY to STALE_TOLERATED, it behaved as this parameter was set to ENFORCED.
So the case was that:
for session - STALE_TOLERATED
for system - ENFORCED
In v$parameter2 against "QUERY_REWRITE_INTEGRITY" was shown "stale_tolerated", but the query was not rewritten.
When I do the same (altering the session and perform the select query) in SQLPlus, everything works as expected - the query is rewritten.
And I conclude the problem is in PL/SQL Developer (my version is 8.0.1.1498) or something related to this.
Edited by: Verdi on 2010-2-12 14:00

Oracle Query Rewrite Alias Problem

Hi,
The problem desribed below is regarding the use of oracle aggregate awareness through the use of query rewrite.
2 materialized views exist (one agg per day, one agg per month) and 1 dimension exists for time (date - month - quarter - year)
Query rewrite seems to be working fine for a query as such (alias sql = alias mv):
select DDFPC.MONTH_NO
from BIDATA_MAIN.DF_REPOSITORY_SUBSET DF2, BIDATA_MAIN.DD_TIME DDFPC
where DF2.FINANCIAL_PROCCESSING_DATE_ID = DDFPC.DATE_ID and DF2.ROUTING_CODE_ISS IN ('FPC','NCC')
group by DDFPC.MONTH_NO
However, considering our reporting tool generates aliases on the fly, we could get the following query (alias sql <> alias mv):
select T2.MONTH_NO
from BIDATA_MAIN.DF_REPOSITORY_SUBSET DF2, BIDATA_MAIN.DD_TIME T2
where DF2.FINANCIAL_PROCCESSING_DATE_ID = T2.DATE_ID and DF2.ROUTING_CODE_ISS IN ('FPC','NCC')
group by T2.MONTH_NO
--> for the second query, query rewrite refuses to correctly use the dimension – it’ll rewrite to the DD (daily) aggregate, but not to the MM (monthly) aggregate
Investigation gives: QSM-01072: materialized view, DA_REPOSITORY_MERCHANT_MM, and query have different joins between tables, DF_REPOSITORY_SUBSET and DD_TIME
So*: How can query rewrite be forced to take place with different aliases between query & materialized view – taken into account a dimension is used for aggregation-awareness?
This seems to indicate it should work...

You are missing a join on the file_id column
i.e.
select sum(f.BLOCKS), sum(d.BLOCKS) from dba_free_space f ,dba_data_files d where f.TABLESPACE_NAME=d.TABLESPACE_NAME and f.TABLESPACE_NAME like SUBSTR('KU_TSD_1',0,10)
and f.file_id = d.file_id
This might have been easier to detect if you had removed the sum aggregation and looked at the data coming back from the raw query.

Oracle 10g Diff in execution plan query with binding var Vs without

We recently did 10g upgrade. In 10g, execution plan differs for query with binding var(thru jdbc etc) Vs without it as given below. For query with binding var,
it chooses poor execution plan(no index is used, full scan is done etc). everything worked fine in 9i. To rectify the problem, we have to hint query with right index,join etc. but i dont like this solution.
I would rather prefer to correct database to choose right execution path instead of eacy query level. but not sure what causes the issue.
Does anybody came across this issue? if so, Please share your experiences. Thanks for the help. Do let me know if you need more info.
1. Query without binding bar:
select * from test where col1 = :1 and col2 = :2
1. Query without binding bar:
select * from test where col1 = 'foo' and col2= 'bar'

I am not an expert but in my humble opinion it is the developer's responsability to ensure the correct explain plan is used before deploying code to production, if the explain plan returned by the DB is bad, then the use of a hint is perfectly acceptable.
Check this out: http://lcgapp.cern.ch/project/CondDB/snapshot/performance.html
Excerpt:
Bind variable peeking. If an SQL query contains bind variables, the optimal execution plan may depend on the values of those variables. When the Oracle query optimizer chooses the execution plan for such a query, it may indeed look at the values of all bind variables involved: this is known as "bind variable peeking".
In summary, the execution plan used for a given SQL query cannot be predicted a priori because it depends on the presence and quality of statistics and on the values of bind variables used at the time the query was first executed (hard-parsed). As a consequence of this instability of execution plans, very different performances may be observed for the same SQL query. In COOL, this issue is addressed by adding Oracle hints to the queries, to make sure that the same (good) plan is used in all cases, even with unreliable statistics or unfavourable bind variables.
Edited by: Rodolfo Ferrari on Jun 3, 2009 9:40 PM

How to create execution plan in DAC and how to start ETL steps

Hi,
For ETL configuration i have installed and configured,
1. Oracle 10G DB
2. obiee and obia 7.9.6
3. informatica server (here i created repository and integration services)
4. DAC server 10g (setup for DAC is also configured like create warehouse tables etc.,
same installation done on windows for client.
Now i'm struck with execution plan creation.
then
how to start ETL, where start ETL
Source : Oracle EBIZ R12.1.1
target : Datawarehouse (10G DB)
please help me out the steps till ETL start ?
Thanks,
Srik

Hi Srik
I am assuming you have followed the steps required before a load in the library for dac config, csv lookups etc...
Did you check out the example in the documentation?
Here is the link
http://download.oracle.com/docs/cd/E14223_01/bia.796/e14217/windows_ic.htm#BABFGIHE
If you follow those steps and run the execution plan and you can monitor the progress under the current run tab in the dac and the infa workflow monitor.
Regards
Nick
Edited by: Nickho on 2010/06/21 9:24 AM

Error while building execution plan

Hi, I'm trying to create an execution plan with container EBS 11.5.10 and subject area Project Analytics.
I get this error while building:
PA-EBS11510
MESSAGE:::group TASK_GROUP_Load_PositionHierarchy for SIL_PositionDimensionHierarchy_PostChangeTmp is not found!!!
EXCEPTION CLASS::: java.lang.NullPointerException
com.siebel.analytics.etl.execution.ExecutionPlanDesigner.getExecutionPlanTasks(ExecutionPlanDesigner.java:818)
com.siebel.analytics.etl.execution.ExecutionPlanDesigner.design(ExecutionPlanDesigner.java:1267)
com.siebel.analytics.etl.client.util.tables.DefnBuildHelper.calculate(DefnBuildHelper.java:169)
com.siebel.analytics.etl.client.util.tables.DefnBuildHelper.calculate(DefnBuildHelper.java:119)
com.siebel.analytics.etl.client.view.table.EtlDefnTable.doOperation(EtlDefnTable.java:169)
com.siebel.etl.gui.view.dialogs.WaitDialog.doOperation(WaitDialog.java:53)
com.siebel.etl.gui.view.dialogs.WaitDialog$WorkerThread.run(WaitDialog.java:85)
Sorry for my english, I'm french.
Thank you for helping me

Hi,
Find the what are all the subjectarea's in execution plan having the task 'SIL_PositionDimensionHierarchy_PostChangeTmp ', add the 'TASK_GROUP_Load_PositionHierarchy ' task group to those those subjectares.
Assemble your subject area's and build the execution plan again.
Thanks

Query Rewrite (QSM-01263) and Views in Execution Plan

Similar Messages

Maybe you are looking for