Sort-Merge outer join, why? when?

Hi All,
How Oracle runs/optimizes outer joins has always been my subject of curiocity.
In Oracle documentation V 10.1 -> Performance tuning guide -> Chap. 14 ( The Query Optimizer) -> Go almost at the bottom
There is a small section of "Sort Merge outer joins".
It has a sentence
"When an outer join cannot drive from the outer (preserved) table to the inner (optional) table, it cannot use a hash join or nested loop joins. Then it uses the sort merge outer join for performing the join operation"
Can you help me understanding this ??
Thanks in advance

You actually need a sort-merge join sometimes: a join on inequality can't be run as a hash join, and may be very inefficient as a nested loop.
e.g.
select ...
where del.delivery_date between ord.order_date + 5 and ord.order_date + 8Unfortunately there are other cases where a sort merge join could be a very efficient join mechansim - because of suitable indexes - but the optimizer won't take it because there is a bug (from my perspective, at any rate) in the cost for sorting.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
http://www.jlcomp.demon.co.uk

Similar Messages

Full outer join Bug or my misunderstanding?

CREATE GLOBAL TEMPORARY TABLE BP_ATTRIBUTE_CHARVAL_GTT
   (     "ATTRIBUTE_ID" NUMBER(10,0),
     "PARTNER_ID" NUMBER(10,0),
     "CHAR_VALUE" VARCHAR2(4000 BYTE),
     "LAST_UPDATE_DATE" DATE,
     "DISABLE_DATE" DATE
   ) ON COMMIT DEETE ROWS ;
CREATE TABLE BP_ATTRIBUTE_CHARVAL
   (     "ATTRIBUTE_ID" NUMBER(10,0),
     "PARTNER_ID" NUMBER(10,0),
     "CHAR_VALUE" VARCHAR2(4000 BYTE),
     "LAST_UPDATE_DATE" DATE,
     "DISABLE_DATE" DATE
REM INSERTING into BP_ATTRIBUTE_CHARVAL
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (888854,710326,'1',to_date('29-NOV-06','DD-MON-RR'),to_date('01-JAN-06','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591330,710326,'01',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591321,710326,'N',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591331,710326,'00',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591329,710326,'01',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591332,710326,'01',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591324,710326,'2',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591333,710326,'01',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591323,710326,'X1',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591334,710326,'BS',to_date('09-FEB-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
REM INSERTING into BP_ATTRIBUTE_CHARVAL_GTT
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591330,707408,'01',to_date('29-MAR-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591321,707408,'N',to_date('23-JAN-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591331,707408,'00',to_date('23-JAN-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591329,707408,'01',to_date('23-JAN-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591332,707408,'00',to_date('29-MAR-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591324,707408,'2',to_date('29-MAR-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591333,707408,'01',to_date('23-JAN-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591323,707408,'X1',to_date('23-JAN-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (591334,707408,'BS',to_date('23-JAN-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (876570,707408,'01',to_date('29-MAR-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT (ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (876568,707408,'1234560003264801',to_date('29-MAR-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (876569,707408,'f3a1d996-720e-4e0a-989c-6d4f3e8e629a',to_date('29-MAR-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
Insert into BP_ATTRIBUTE_CHARVAL_GTT(ATTRIBUTE_ID,PARTNER_ID,CHAR_VALUE,LAST_UPDATE_DATE,DISABLE_DATE) values (874948,707408,'20060318000000',to_date('29-MAR-06','DD-MON-RR'),to_date('07-NOV-01','DD-MON-RR'));
select 707408,
       decode(g.attribute_id,NULL,c.attribute_id,g.attribute_id) attribute_id,
       case
       when c.last_update_date is null and g.last_update_date is not null
       then
          g.char_value
        when g.last_update_date is null and c.last_update_date is not null
        then
          c.char_value
        when g.last_update_date >= c.last_update_date
        then
             g.char_value
       else
            c.char_value
       end   char_value,
       decode(g.last_update_date,c.last_update_date,g.last_update_date,c.last_update_date) last_update_date,
       decode(g.disable_date,c.disable_date,g.disable_date,c.disable_date) disable_date
from bp_attribute_charval_gtt g
full outer join
     bp_attribute_charval c
on c.attribute_id = g.attribute_id
where c.partner_id=710326;Hi Guys
When I run the above query I get a problem.
I am expecting to see is a merge of all the attribute_id's and their values.
The query does not appear to be merging the data as intended.
My understanding of the full outer join is that its a combination of left and outer joins,
so the above query is intended to return with the total number of unique attributes
and their appropriate values
a) I have a bug in the Sql
b) This is an oracle bug
c) My understanding is incorrect
Please Help
Message was edited by:
Keith Jamieson (fixed insert statements for gtt )

How do you expect a full outer join operation when you have given --
where c.partner_id=710326;According to your supplied data - i don't think your query can perform that full outer join operation because of that filtration. Just remove that last condition and checked it. You will get your desired result - hopefully.
"It's like you want to view the things by closing down your both eyes". Do you think it will pay?
Regards.
Satyaki De.

OWB does not allow full outer join

I got following error (twice) while validating my mapping: "VLD-1506: Invalid Expression: Mixing full and partial outer joins in one mapping is not supported".
I have following join conditions in my mapping:
1) INGRP1.DISTRICT_ID = INGRP2.DISTRICT_ID And INGRP1.CHARGE_PERIOD_ID = INGRP2.CHARGE_PERIOD_ID And INGRP1.UTL_ID = INGRP2.UTL_ID
2) The same
3) INGRP1.CHARGE_PERIOD_ID (+) = INGRP2.CHARGE_PERIOD_ID (+) And
INGRP1.DISTRICT_ID (+) = INGRP2.DISTRICT_ID (+) And
INGRP1.PROVIDER# (+) = INGRP2.PROVIDER# (+)
I suppose there is not any partial joins here. I tried to make first and second conditions with full outer joins too:
INGRP1.DISTRICT_ID (+) = INGRP2.DISTRICT_ID (+) And
INGRP1.CHARGE_PERIOD_ID (+) = INGRP2.CHARGE_PERIOD_ID (+) And
INGRP1.UTL_ID (+) = INGRP2.UTL_ID (+) And
INGRP1.DISTRICT_ID IS NOT NULL And
INGRP2.DISTRICT_ID IS NOT NULL
If I do this, validation reports the same error, but six times instead of twice.
If I remove outer joins OWB generates following mapping statement:
MERGE
/*+ APPEND PARALLEL(MMB$ACCOUNT, DEFAULT, DEFAULT) */
INTO
"MMB$ACCOUNT"
USING
(SELECT
/*+ NO_MERGE */
"INGRP1"."DISTRICT_ID" "DISTRICT_ID",
DIC$TIME_RECODER."MONTH_ID" "MONTH_ID",
"INGRP1"."PROVIDER#" "PROVIDER#",
"INGRP1"."ACCOUNT_NO" "ACCOUNT_NO",
"INGRP2"."ACCOUNT_NO" "ACCOUNT_NO_1"
FROM "DIC$TIME_RECODER" DIC$TIME_RECODER,
(SELECT
/*+ DRIVING_SITE("AGG"."AGG_INPUT_SUBQUERY"."FC_CHARGES_1_GKH_REL2_GKH_STAR") */
"AGG"."CHARGE_PERIOD_ID" "CHARGE_PERIOD_ID",
"AGG"."DISTRICT_ID$0" "DISTRICT_ID",
"AGG"."PROVIDER#$0" "PROVIDER#",
"AGG"."ACCOUNT_NO$0" "ACCOUNT_NO"
FROM (SELECT
("AGG_INPUT_SUBQUERY"."CHARGE_PERIOD_ID$0") "CHARGE_PERIOD_ID",
("AGG_INPUT_SUBQUERY"."DISTRICT_ID$1") "DISTRICT_ID$0",
("AGG_INPUT_SUBQUERY"."PROVIDER#$1") "PROVIDER#$0",
COUNT(DISTINCT ("AGG_INPUT_SUBQUERY"."ACCOUNT_NO$1")) "ACCOUNT_NO$0"
FROM (SELECT
"INGRP1"."DISTRICT_ID" "DISTRICT_ID$1",
"INGRP1"."CHARGE_PERIOD_ID" "CHARGE_PERIOD_ID$0",
DM_UTILITIES_1_GKH_R14554."PROVIDER#" "PROVIDER#$1",
"FC_CHARGES_1_GKH_REL2_GKH_STAR"."ACCOUNT_NO" "ACCOUNT_NO$1"
FROM {"FC_CHARGES"@GKH_REL2_GKH_STAR} "FC_CHARGES_1_GKH_REL2_GKH_STAR",
{"DM_UTILITIES"@GKH_REL2_GKH_STAR} DM_UTILITIES_1_GKH_R14554,
(SELECT
"DEDUP"."DISTRICT_ID$2" "DISTRICT_ID",
"DEDUP"."CHARGE_PERIOD_ID$1" "CHARGE_PERIOD_ID",
"DEDUP"."UTL_ID" "UTL_ID"
FROM (SELECT
DISTINCT
"FC_CHARGES_GKH_REL2_GKH_STAR"."DISTRICT_ID" "DISTRICT_ID$2",
"FC_CHARGES_GKH_REL2_GKH_STAR"."CHARGE_PERIOD_ID" "CHARGE_PERIOD_ID$1",
"FC_CHARGES_GKH_REL2_GKH_STAR"."UTL_ID" "UTL_ID"
FROM {"FC_CHARGES"@GKH_REL2_GKH_STAR} "FC_CHARGES_GKH_REL2_GKH_STAR" WHERE ( (MAP_DIC$ACCOUNT."DATE_START") <= coalesce ( "FC_CHARGES_GKH_REL2_GKH_STAR"."CHANGED_DATE_#" , "FC_CHARGES_GKH_REL2_GKH_STAR"."CREATED_DATE_#" ) )) "DEDUP" ) "INGRP1" WHERE ( "INGRP1"."DISTRICT_ID" = "FC_CHARGES_1_GKH_REL2_GKH_STAR"."DISTRICT_ID" ) AND
( "INGRP1"."CHARGE_PERIOD_ID" = "FC_CHARGES_1_GKH_REL2_GKH_STAR"."CHARGE_PERIOD_ID" ) AND
( "INGRP1"."UTL_ID" = "FC_CHARGES_1_GKH_REL2_GKH_STAR"."UTL_ID" ) AND
( ( DM_UTILITIES_1_GKH_R14554."UTL_ID" (+) = "INGRP1"."UTL_ID" ) )) "AGG_INPUT_SUBQUERY"
GROUP BY
("AGG_INPUT_SUBQUERY"."DISTRICT_ID$1"), ("AGG_INPUT_SUBQUERY"."CHARGE_PERIOD_ID$0"), ("AGG_INPUT_SUBQUERY"."PROVIDER#$1")) "AGG" ) "INGRP1",
(SELECT
/*+ DRIVING_SITE("AGG_1"."AGG_INPUT_SUBQUERY$0"."FC_PAYMENTS_1_GKH_RE143940") */
"AGG_1"."PROVIDER#$2" "PROVIDER#",
"AGG_1"."DISTRICT_ID$3" "DISTRICT_ID",
"AGG_1"."CHARGE_PERIOD_ID$2" "CHARGE_PERIOD_ID",
"AGG_1"."ACCOUNT_NO$2" "ACCOUNT_NO"
FROM (SELECT
("AGG_INPUT_SUBQUERY$0"."PROVIDER#$3") "PROVIDER#$2",
("AGG_INPUT_SUBQUERY$0"."DISTRICT_ID$4") "DISTRICT_ID$3",
("AGG_INPUT_SUBQUERY$0"."CHARGE_PERIOD_ID$3") "CHARGE_PERIOD_ID$2",
COUNT(DISTINCT ("AGG_INPUT_SUBQUERY$0"."ACCOUNT_NO$3")) "ACCOUNT_NO$2"
FROM (SELECT
"INGRP1"."DISTRICT_ID" "DISTRICT_ID$4",
"INGRP1"."CHARGE_PERIOD_ID" "CHARGE_PERIOD_ID$3",
DM_UTILITIES_GKH_REL2_GKH."PROVIDER#" "PROVIDER#$3",
"FC_PAYMENTS_1_GKH_RE143940"."ACCOUNT_NO" "ACCOUNT_NO$3"
FROM {"FC_PAYMENTS"@GKH_REL2_GKH_STAR} "FC_PAYMENTS_1_GKH_RE143940",
{"DM_UTILITIES"@GKH_REL2_GKH_STAR} DM_UTILITIES_GKH_REL2_GKH,
(SELECT
"DEDUP_1"."DISTRICT_ID$5" "DISTRICT_ID",
"DEDUP_1"."CHARGE_PERIOD_ID$4" "CHARGE_PERIOD_ID",
"DEDUP_1"."UTL_ID$0" "UTL_ID"
FROM (SELECT
DISTINCT
"FC_PAYMENTS_GKH_REL2_GKH_STAR"."DISTRICT_ID" "DISTRICT_ID$5",
"FC_PAYMENTS_GKH_REL2_GKH_STAR"."CHARGE_PERIOD_ID" "CHARGE_PERIOD_ID$4",
"FC_PAYMENTS_GKH_REL2_GKH_STAR"."UTL_ID" "UTL_ID$0"
FROM {"FC_PAYMENTS"@GKH_REL2_GKH_STAR} "FC_PAYMENTS_GKH_REL2_GKH_STAR" WHERE ( (MAP_DIC$ACCOUNT."DATE_START") <= coalesce ( "FC_PAYMENTS_GKH_REL2_GKH_STAR"."CHANGED_DATE_#" , "FC_PAYMENTS_GKH_REL2_GKH_STAR"."CREATED_DATE_#" ) )) "DEDUP_1" ) "INGRP1" WHERE ( "INGRP1"."DISTRICT_ID" = "FC_PAYMENTS_1_GKH_RE143940"."DISTRICT_ID" ) AND
( "INGRP1"."CHARGE_PERIOD_ID" = "FC_PAYMENTS_1_GKH_RE143940"."CHARGE_PERIOD_ID" ) AND
( "INGRP1"."UTL_ID" = "FC_PAYMENTS_1_GKH_RE143940"."UTL_ID" ) AND
( ( DM_UTILITIES_GKH_REL2_GKH."UTL_ID" (+) = "INGRP1"."UTL_ID" ) )) "AGG_INPUT_SUBQUERY$0"
GROUP BY
("AGG_INPUT_SUBQUERY$0"."DISTRICT_ID$4"), ("AGG_INPUT_SUBQUERY$0"."CHARGE_PERIOD_ID$3"), ("AGG_INPUT_SUBQUERY$0"."PROVIDER#$3")) "AGG_1" ) "INGRP2" WHERE ( "INGRP1"."CHARGE_PERIOD_ID" = "INGRP2"."CHARGE_PERIOD_ID" ) AND
( "INGRP1"."DISTRICT_ID" = "INGRP2"."DISTRICT_ID" ) AND
( "INGRP1"."PROVIDER#" = "INGRP2"."PROVIDER#" ) AND
( ( DIC$TIME_RECODER."PERIOD_ID" (+) = "INGRP1"."CHARGE_PERIOD_ID" ) )
) "MERGEQUERY_325"
ON (
"MMB$ACCOUNT"."DISTRICT_ID" = "MERGEQUERY_325"."DISTRICT_ID" AND
"MMB$ACCOUNT"."MONTH_ID" = "MERGEQUERY_325"."MONTH_ID" AND
"MMB$ACCOUNT"."PROVIDER_ID" = "MERGEQUERY_325"."PROVIDER#" )
WHEN NOT MATCHED THEN
INSERT
("MMB$ACCOUNT"."DISTRICT_ID",
"MMB$ACCOUNT"."MONTH_ID",
"MMB$ACCOUNT"."PROVIDER_ID",
"MMB$ACCOUNT"."QNT_CHARGED",
"MMB$ACCOUNT"."QNT_PAID")
VALUES
("MERGEQUERY_325"."DISTRICT_ID",
"MERGEQUERY_325"."MONTH_ID",
"MERGEQUERY_325"."PROVIDER#",
"MERGEQUERY_325"."ACCOUNT_NO",
"MERGEQUERY_325"."ACCOUNT_NO_1")
WHEN MATCHED THEN
UPDATE
SET
"QNT_CHARGED" = "MERGEQUERY_325"."ACCOUNT_NO",
"QNT_PAID" = "MERGEQUERY_325"."ACCOUNT_NO_1";
What does it mean? Is JOINER's full outer join is incompatible with KEY LOOKUP operator and KL should be replaced with WB_LOOKUP_NUM?

Sanders,
Key lookup always does a partial outer join. When the full outer join and partial outer join conditions are put together, there is no available syntax to facilitate it.
The way to this to generate the join operator (with full outer join) first in a subquery, then generate the key lookup as the outer query. Or the other way around, first the key lookup then the full outer join. The important part is that the key lookup can't be merged into the FROM-list.
So there are two workarounds. One is what you already pointed out, using WB_LOOKUP_NUM.
The other is to explicitly spell out the key lookup logic in the mapping by introducing a join with the lookup table, like this.
Change
Table1
.......... Join (w/ foj cond.) ---> KeyLookup
Table2
to
Table1
.......... Join (w/ foj cond)
Table2 ........................ Join (w/ poj cond.) ---> Lookup table
Nikolai Rochnik

Full outer join

CREATE TABLE FEE_BANDS_AUD1
    AUDIT_DATE TIMESTAMP (6) NOT NULL ENABLE,
    AUDIT_ACTION          VARCHAR2(30 BYTE) NOT NULL ENABLE,
    AUDIT_USER            VARCHAR2(8 BYTE) NOT NULL ENABLE,
    FEE_BANDS_ID          NUMBER NOT NULL ENABLE,
    FEE_RULE              VARCHAR2(10 BYTE) NOT NULL ENABLE,
    FEE_BAND_LOWER_LIMIT NUMBER(19,0),
    FEE_BAND_HIGHER_LIMIT NUMBER(19,0),
    RATE_PERCENT          NUMBER(11,4),
    RATE_NUMBER           NUMBER(21,2),
    CAL_BASED_ON          CHAR(1 BYTE) NOT NULL ENABLE,
    REC_SEQ               NUMBER(5,0) NOT NULL ENABLE)
    FEE_BANDS_AUD
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 06:31:56.625000000 AM','CREATE','sdn',1,'NSK',0,9999999999999999999,11,0,'B',0);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 06:53:08.659000000 AM','UPDATE','sdn',1,'NSK',0,100,11,0,'B',1);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 06:53:08.659000000 AM','UPDATE','sdn',2,'NSK',101,9999999999999999999,1,0,'B',1);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 06:54:51.354000000 AM','UPDATE','sdn',1,'NSK',0,100,11,0,'B',2);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 06:54:51.354000000 AM','UPDATE','sdn',2,'NSK',101,9999999999999999999,33,0,'B',2);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:15:16.354000000 AM','UPDATE','sdn',1,'NSK',0,100,11,0,'B',3);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:15:16.354000000 AM','UPDATE','sdn',2,'NSK',101,200,33,0,'B',3);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:15:16.354000000 AM','UPDATE','sdn',3,'NSK',201,9999999999999999999,1,0,'B',3);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:15:53.341000000 AM','UPDATE','sdn',1,'NSK',0,100,11,0,'B',4);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:15:53.341000000 AM','UPDATE','sdn',2,'NSK',101,200,33,0,'B',4);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:15:53.341000000 AM','UPDATE','sdn',3,'NSK',201,9999999999999999999,2,0,'B',4);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:18:52.118000000 AM','UPDATE','sdn',1,'NSK',0,100,11,0,'B',5);
INSERT INTO FEE_BANDS_AUD1 VALUES('18-10-10 07:18:52.118000000 AM','UPDATE','sdn',2,'NSK',101,9999999999999999999,2,0,'B',5);     I have a bandId, in which i will update a new band or delete a band. Each time when i insert,update or delete rec_seq is incremented to one to identify the old set of bands and new set of bands.
My problem here is when i deleted a band (which is last two insert statments from the above) those are not coming in the old values . It should come in the old value set and new value should come as null.
I am using full outer join because when i create a new record there wont be any old values in this case old values should come as null and also i delete any values there wont be any new value for that so new should come as null
This is the query im trying
select
O.REC_SEQ,O.audit_action,O.fee_bands_id, O.FEE_RULE,
O.FEE_BAND_LOWER_LIMIT, O.FEE_BAND_HIGHER_LIMIT,O.CAL_BASED_ON,
N.REC_SEQ,n.audit_action,n.fee_bands_id, N.FEE_RULE,
N.FEE_BAND_LOWER_LIMIT, N.FEE_BAND_HIGHER_LIMIT,N.CAL_BASED_ON
from fee_bands_aud1 O FULL OUTER JOIN fee_bands_aud1 N
on (N.fee_bands_id = O.fee_bands_id
and N.FEE_RULE = O.FEE_RULE
and O.REC_SEQ = N.REC_SEQ-1)
where N.FEE_RULE = 'NSK'
order by N.REC_SEQ, n.fee_bands_idwhat is the problem anybody please help i am very new to oracle.

Yes, it's possible.
Search for "full outer join" in the online manuals
http://tahiti.oracle.com/pls/db92/db92.drilldown?levelnum=2&toplevel=a96540&method=FULL&chapters=0&book=&wildcards=1&preference=&expand_all=&verb=&word=full+outer+join+#a96540
In the SQL Reference you can find an example

Using full outer join of subqueries named using with clause

Hi,
I am trying to create a view which is having 2 subqueries vol1 & vol2 with WITH clause. I am joining those 2 subqueries in the main query with FULL OUTER JOIN.
When i compile that view in a tool like pl/sql developer, It has been compiled successfully.
But when i call the view creation script from SQL command prompt, It is throwing error as
from vol1 FULL JOIN vol2 o ON (vol1.ct_reference = vol2.ct_reference and vol1.table_name = vol2.table_name
ERROR at line 29:
ORA-00942: table or view does not exist
Kindly advise whats going wrong.

that's line 29. Maybe you get a better idea if you strip your operation of all the unneccessary elements until it works.
There are some known bugs with subquery factoring (aka with clause) and also with ANSI join syntax, but it is hard to tell what happens here based on your description. But one thing is strange - if it is not a result of formatting (not formatting): I would expect the asterisk beneath the unknown table and not beneath the key word FULL.
P.S.: my editor makes me think it's rather a proportional font thing. Have I already said that I don't like proportional font for SQL code examples?

Sample code and senarios to use outer join?

We know the ABAP4 syntax for inner join, but never tried outer join and we even don't know if there is any outer join syntax in ABAP4 or not. Would be very appreciated if some ABAP expert here let us know if there is any outer join and list the difference between inner join and outer join with detailed senarios or when we would use outer join or when to use inner join? Also give a sample code on the outer join if there is any in ABAP?
Thanks and we will give you reward points!

Hye..
Left outer join between table 1 and table 2 where column D in both tables set the join condition:
Table 1                      Table 2
A
B
C
D
D
E
F
G
H
a1
b1
c1
1
1
e1
f1
g1
h1
a2
b2
c2
1
3
e2
f2
g2
h2
a3
b3
c3
2
4
e3
f3
g3
h3
a4
b4
c4
3
|--|||--|
    Left Outer Join
    |--||||||||--|
    | A | B | C | D | D | E | F | G | H |
    |--||||||||--|
    | a1 | b1 | c1 | 1 | 1 | e1 | f1 | g1 | h1 |
    | a2 | b2 | c2 | 1 | 1 | e1 | f1 | g1 | h1 |
    | a3 | b3 | c3 | 2 |NULL|NULL|NULL|NULL|NULL|
    | a4 | b4 | c4 | 3 | 3 | e2 | f2 | g2 | h2 |
    |--||||||||--|
Example
Output a list of all custimers with their bookings for October 15th, 2001:
DATA: CUSTOMER TYPE SCUSTOM,
      BOOKING TYPE SBOOK.
SELECT SCUSTOMNAME SCUSTOMPOSTCODE SCUSTOM~CITY
       SBOOKFLDATE SBOOKCARRID SBOOKCONNID SBOOKBOOKID
       INTO (CUSTOMER-NAME, CUSTOMER-POSTCODE, CUSTOMER-CITY,
             BOOKING-FLDATE, BOOKING-CARRID, BOOKING-CONNID,
             BOOKING-BOOKID)
       FROM SCUSTOM LEFT OUTER JOIN SBOOK
         ON SCUSTOMID = SBOOKCUSTOMID AND
            SBOOK~FLDATE = '20011015'
       ORDER BY SCUSTOMNAME SBOOKFLDATE.
WRITE: / CUSTOMER-NAME, CUSTOMER-POSTCODE, CUSTOMER-CITY,
           BOOKING-FLDATE, BOOKING-CARRID, BOOKING-CONNID,
           BOOKING-BOOKID.
ENDSELECT.
Reward if helpful.
Thanks.
Imran.

One-to-one two sided relationship causing two outer joins.

We have a fairly simple one-to-one relationship between two objects A and
B. A maps to table A, B maps to table B. A holds a foreign key to B. Both
classes hold a reference to each other.
What we are trying to achieve is to load both A and B with a single
intelligent SQL query. The only thing we can achieve is either two queries
or one query with two outer joins.
When both A and B have the other in the default fetch group and
EagerFetchMode set to join, Kodo dispatches is something like this:
SELECT whatever FROM A t0 LEFT OUTER JOIN B t1 ON t0.B_ID = t1.ID LEFT
OUTER JOIN A t2 ON t1.ID = t2.B_ID
The obvious problem with this is that is is going to be very innefficient.
Isn't the second join needed?
If the eager fetch mode is kept the same but A is removed from the default
fetch group of B then we get two queries. The first one is a left outer
join between A and B and loads all the columns from both A and B. (At this
point in a debugger, A holds a reference to B, but B's reference to A is
null). The second query fetchs all columns from B. But still the reference
to A is null. It's only when we actually navigate to A from a B that the
reference is populated. (Luckily no query is executed at this point).
Is there anyway to achieve the loading of both objects with a single SQL
query dispatched by Kodo?

You should be able to get what you want by querying for the B instance with A in
its default fetch group (but keeping B out of A's default fetch group). It
shoudl result in one query with a single outer join, and no additional queries
when you traverse the A.B relation.
The reason for the two joins/queries in other scenarios is that Kodo treats each
direction of the relation as a separate relation that has to be fetched on its
own. The reason the above solution should work is that when the A record is
read, the foreign key values for the B record are cached. When you traverse the
A.B relation after both A and B are loaded, Kodo matches these cached foreign
key values to the B instance in the PM cache and doesn't require a DB trip.

Why, when I sync my iPhone does it always take all my apps out of their neat sorted little boxes of twelve Apps organised by a commonality and rearrange them over a dozen screens in random order? Each time I sync, I have a 1hr long task of relocating apps

Why, when I sync my iPhone does it always take all my apps out of their neat sorted little boxes of twelve Apps organised by a commonality and rearrange them over a dozen screens in random order? Each time I sync, I have a 1hr long task of relocating apps.
Why no tleave them spread out I hear you ask... That is not practicable. I then have 12 pages to scan rather than just two. I need a solution... :-P

I realize this is an old thread but I'm having the same problem after upgrading my software today. Kinda surprised there are no solutions at all with 88 views. I have an iPod touch btw, not an iPhone, but it prob wouldn't make much difference in this case.
The thing is, I get the screen(s) looking EXACTLY as I want on iTunes...just perfect (which is what I believe everyone else is experiencing as well). When we go to sync tho, it does whatever it wants to do. After syncing, all the apps are there, it's just that for me, it puts them in some type of random order. I have 72 apps and this is absolutely ridiculous!
Thanks in advance for any fixes anyone might have...

Not using Index when SDO_RELATE in Spatial Query is used in LEFT OUTER JOIN

I want to know for every City (Point geometry) in which Municipality (Polygon geometry) it is.
Some cities will not be covered by any municipality (as there is no data for it), so its municipality name should be blank in the result
We have 4942 cities (point geometries)
and 500 municipalities (polygon geometry)
SELECT T1.NAME as City, T2.NAME as Municipality
FROM CITY T1
LEFT OUTER JOIN MUNICIPALITY T2 ON SDO_RELATE(T1.GEOM, T2.GEOM, 'MASK=ANYINTERACT') = 'TRUE'The explain plan for this query is:
SELECT STATEMENT
FILTER
    Filter Predicates
      MDSYS.SDO_RTREE_RELATE(T1.GEOM, T2.GEOM, 'mask=ANYINTERACT querytype=window ') = 'TRUE'
    MERGE JOIN
      TABLE ACCESS              CITY               FULL                            11
      BUFFER                                       SORT                        100605
          TABLE ACCESS          MUNICIPALITY       FULL                            20So the cost is in the BUFFER (whatever that is), it takes +2000 seconds to run this, it is not using the spatial index.
And we are not getting all rows, but only the ones interacting with a municipality, e.g. 2436 rows.
But I want all rows, including the ones not interacting with any Municipality.
When we want only those cities that actually are in a municipality, I use a different query and it will use the index.
SELECT T1.NAME as City, T2.NAME as Municipality
FROM CITY T1, MUNICIPALITY T2
WHERE SDO_RELATE(T1.GEOM, T2.GEOM, 'MASK=ANYINTERACT') = 'TRUE'I get (only) 2436 rows (as expected) in 5 seconds (it is fast) and the explain plan shows it is using the spatial index.
But in this case, I am not getting any cities not inside any municipality (of course)
SELECT STATEMENT
   NESTED LOOPS
      TABLE ACCESS                   MUNICIPALITY       FULL                22
      TABLE ACCESS                   CITY               BY INDEX ROWID      22
         DOMAIN INDEX                CITY_SDX                                0
            Access Predicates
               MDSYS.SDO_RTREE_RELATE(T1.GEOM, T2.GEOM, 'mask=ANYINTERACT querytype=window ') = 'TRUE'I always thought a LEFT OUTER JOIN would return all rows from the Table, whatever happens in the next,
but it seems the query has been rewritten so that it is now using a Filter Predicate in the end, which filters those geometries having no interaction.
As an example I also do thing alphanumerically, I do get 4942 rows, including the ones which have no Municipality name.
In this case the names must match, so its only for testing if the LEFT OUTER JOIN returns stuff correctly, which it does in this case.
SELECT T1.NAME as City, T2.NAME as Municipality
FROM CITY T1
LEFT OUTER JOIN MUNICIPALITY T2 ON T1.NAME = T2.NAMEIs this an Oracle Spatial bug, e.g. not return 4942 rows, but only 2436 rows on the first query?
Note all tests performed on Oracle 11g R2 (11.2.0.1.0)

Patrick,
Even so, your geoms in the relate were the wrong way around.
Also, I don't recall you saying (or showing) that you wanted the municipality geometry returned. Still,
no matter, easy to do.
Here are some additional suggestions. I don't have your data so I have had to use some of my own.
set serveroutput on timing on autotrace on
SELECT T1.SPECIES as City,
       (SELECT T2.ADMIN_NAME FROM AUSTRALIAN_STATES T2 WHERE SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE') as Municipality,
       (SELECT T2.GEOM       FROM AUSTRALIAN_STATES T2 WHERE SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE') as geom
FROM GUTDATA T1;
762 rows selected
Elapsed: 00:00:21.656
Plan hash value: 2160035213
| Id | Operation                   | Name                       | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT            |                            |   762 | 49530 |     5   (0)| 00:00:01 |
|   1 | TABLE ACCESS BY INDEX ROWID| AUSTRALIAN_STATES          |     1 |   115 |     0   (0)| 00:00:01 |
|* 2 |   DOMAIN INDEX              | AUSTRALIAN_STATES_GEOM_SPX |       |       |     0   (0)| 00:00:01 |
|   3 | TABLE ACCESS BY INDEX ROWID| AUSTRALIAN_STATES          |     1 |   115 |     0   (0)| 00:00:01 |
|* 4 |   DOMAIN INDEX              | AUSTRALIAN_STATES_GEOM_SPX |       |       |     0   (0)| 00:00:01 |
|   5 | TABLE ACCESS FULL          | GUTDATA                    |   762 | 49530 |     5   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   2 - access("MDSYS"."SDO_ANYINTERACT"("T2"."GEOM","SDO_GEOM"."SDO_BUFFER"(:B1,10000,0.5,'UNIT=M'))='TRUE')
   4 - access("MDSYS"."SDO_ANYINTERACT"("T2"."GEOM","SDO_GEOM"."SDO_BUFFER"(:B1,10000,0.5,'UNIT=M'))='TRUE')
   Statistics
               7 user calls
           24576 physical read total bytes
               0 physical write total bytes
               0 spare statistic 3
               0 commit cleanout failures: cannot pin
               0 TBS Extension: bytes extended
               0 total number of times SMON posted
               0 SMON posted for undo segment recovery
               0 SMON posted for dropping temp segment
               0 segment prealloc tasksThe above can look messy as you add more (SELECT ...) attributes, but is is fast (though can't use in Materialized Views).
/* The set of all cities not in municipalities */
SELECT T1.SPECIES                 as City,
       cast(null as varchar2(42)) as municipality,
       cast(null as sdo_geometry) as geom
FROM GUTDATA T1
WHERE NOT EXISTS (SELECT 1
                     FROM AUSTRALIAN_STATES T2
                    WHERE SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE')
UNION ALL
/* The set of all cities in municipalities */
SELECT T1.SPECIES    as City,
       T2.ADMIN_NAME as Municipality,
       T2.GEOM       as geom
FROM GUTDATA T1
       INNER JOIN
       AUSTRALIAN_STATES T2 ON (SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE');
762 rows selected
Elapsed: 00:00:59.953
Plan hash value: 2854682795
| Id | Operation           | Name                       | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT    |                            |    99 | 13450 |    38 (87)| 00:00:01 |
|   1 | UNION-ALL          |                            |       |       |            |          |
|* 2 |   FILTER            |                            |       |       |            |          |
|   3 |    TABLE ACCESS FULL| GUTDATA                    |   762 | 49530 |     5   (0)| 00:00:01 |
|* 4 |    DOMAIN INDEX     | AUSTRALIAN_STATES_GEOM_SPX |       |       |     0   (0)| 00:00:01 |
|   5 |   NESTED LOOPS      |                            |    61 | 10980 |    33   (0)| 00:00:01 |
|   6 |    TABLE ACCESS FULL| AUSTRALIAN_STATES          |     8 |   920 |     3   (0)| 00:00:01 |
|* 7 |    TABLE ACCESS FULL| GUTDATA                    |     8 |   520 |     4   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   2 - filter( NOT EXISTS (SELECT 0 FROM "AUSTRALIAN_STATES" "T2" WHERE "MDSYS"."SDO_ANYINTERACT"("T2"."GEOM","SDO_GEOM"."SDO_BUFFER"(:B1,10000,0.5,'UNIT=M'))='TRUE'))
   4 - access("MDSYS"."SDO_ANYINTERACT"("T2"."GEOM","SDO_GEOM"."SDO_BUFFER"(:B1,10000,0.5,'UNIT=M'))='TRUE')
   7 - filter("MDSYS"."SDO_ANYINTERACT"("T2"."GEOM","SDO_GEOM"."SDO_BUFFER"("T1"."GEOM",10000,0.5,'UNIT=M'))='TRUE')
   Statistics
               7 user calls
          131072 physical read total bytes
               0 physical write total bytes
               0 spare statistic 3
               0 commit cleanout failures: cannot pin
               0 TBS Extension: bytes extended
               0 total number of times SMON posted
               0 SMON posted for undo segment recovery
               0 SMON posted for dropping temp segment
               0 segment prealloc tasksMuch slower but Materialized View friendly.
This one is a bit more "natural" but still slower than the first.
set serveroutput on timing on autotrace on
/* The set of all cities in municipalities */
WITH municipal_cities As (
SELECT T1.ID         as City,
         T2.ADMIN_NAME as Municipality,
         T2.GEOM       as geom
    FROM GUTDATA T1
         INNER JOIN
         AUSTRALIAN_STATES T2 ON (SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE')
SELECT T1.ID           as City,
       T2.Municipality as Municipality,
       T2.GEOM         as geom
FROM GUTDATA          T1
       LEFT OUTER JOIN
       municipal_cities T2
       ON (T2.CITY = T1.ID);
762 rows selected
Elapsed: 00:00:50.228
Plan hash value: 745978991
| Id | Operation             | Name              | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT      |                   |   762 | 44196 |    36   (3)| 00:00:01 |
|* 1 | HASH JOIN RIGHT OUTER|                   |   762 | 44196 |    36   (3)| 00:00:01 |
|   2 |   VIEW                |                   |    61 | 3294 |    33   (0)| 00:00:01 |
|   3 |    NESTED LOOPS       |                   |    61 | 10980 |    33   (0)| 00:00:01 |
|   4 |     TABLE ACCESS FULL | AUSTRALIAN_STATES |     8 |   920 |     3   (0)| 00:00:01 |
|* 5 |     TABLE ACCESS FULL | GUTDATA           |     8 |   520 |     4   (0)| 00:00:01 |
|   6 |   INDEX FAST FULL SCAN| GUTDATA_ID_PK     |   762 | 3048 |     2   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   1 - access("T2"."CITY"(+)="T1"."ID")
   5 - filter("MDSYS"."SDO_ANYINTERACT"("T2"."GEOM","SDO_GEOM"."SDO_BUFFER"("T1"."GEOM",10000,0.5,'UNIT=M'))='TRUE')
   Statistics
               7 user calls
           49152 physical read total bytes
               0 physical write total bytes
               0 spare statistic 3
               0 commit cleanout failures: cannot pin
               0 TBS Extension: bytes extended
               0 total number of times SMON posted
               0 SMON posted for undo segment recovery
               0 SMON posted for dropping temp segment
               0 segment prealloc tasksFinally, the Pièce de résistance: trick the LEFT OUTER JOIN operator...
set serveroutput on timing on autotrace on
SELECT T1.SPECIES    as City,
       T2.ADMIN_NAME as Municipality,
       T2.GEOM       as geom
FROM GUTDATA           T1
       LEFT OUTER JOIN
       AUSTRALIAN_STATES T2
       ON (t2.admin_name = to_char(t1.ID) OR
           SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE');
762 rows selected
Elapsed: 00:00:50.273
Plan hash value: 158854308
| Id | Operation           | Name              | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT    |                   |   762 | 92964 | 2294   (1)| 00:00:28 |
|   1 | NESTED LOOPS OUTER |                   |   762 | 92964 | 2294   (1)| 00:00:28 |
|   2 |   TABLE ACCESS FULL | GUTDATA           |   762 | 49530 |     5   (0)| 00:00:01 |
|   3 |   VIEW              |                   |     1 |    57 |     3   (0)| 00:00:01 |
|* 4 |    TABLE ACCESS FULL| AUSTRALIAN_STATES |     1 |   115 |     3   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   4 - filter("T2"."ADMIN_NAME"=TO_CHAR("T1"."ID") OR
              "MDSYS"."SDO_ANYINTERACT"("T2"."GEOM","SDO_GEOM"."SDO_BUFFER"("T1"."GEOM",10000,0.5,'UNIT=M'))='TRUE')
   Statistics
               7 user calls
               0 physical read total bytes
               0 physical write total bytes
               0 spare statistic 3
               0 commit cleanout failures: cannot pin
               0 TBS Extension: bytes extended
               0 total number of times SMON posted
               0 SMON posted for undo segment recovery
               0 SMON posted for dropping temp segment
               0 segment prealloc tasksTry these combinations to see what works for you.
Interestingly, for me, the following returns absolutely nothing.
SELECT T1.SPECIES    as City,
       T2.ADMIN_NAME as Municipality
FROM GUTDATA           T1
       LEFT OUTER JOIN
       AUSTRALIAN_STATES T2
       ON (SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE')
MINUS
SELECT T1.SPECIES    as City,
       T2.ADMIN_NAME as Municipality
FROM GUTDATA           T1
       LEFT OUTER JOIN
       AUSTRALIAN_STATES T2
       ON (t2.admin_name = to_char(t1.ID) OR
           SDO_ANYINTERACT(T2.GEOM, SDO_GEOM.SDO_BUFFER(T1.GEOM,10000,0.5,'UNIT=M')) = 'TRUE');(I leave it to you to see if you can see why as the LEFT OUTER JOIN seems to be working correctly for me but I am not going to dedicate time to detailed checking of results.)
Note all tests performed on Oracle 11g R2 (11.2.0.1.0)
If you get the answer you want: mark the post as answered to assign points.
regards
Simon

Nested loop join v/s Sort merge

I have seen that nested loops are better if the inner table is being indexed, because for each outer table row, we are looking for a match in the inner table. But is there any case when optimizer still goes for a nested loop even if there is no index on the inner table. That is my first question ?
My second question := When doing a sort merge join oracle has to sort both result sets and then merge them. Oracle says that if both the row sets, if already sorted is definately better for performance. Ya thats obvious. But back to my upper question, when there is no index on the inner table, is it the situation when oracle goes for a sort merge join ?

My response should really have examples but since I do not have any handy I will just say about your first question. If there is no index available from table A to table B yes it is possible a nested loop join may still be used and table B read via full table scan within a nested loop. If table B is very small and consists of only a block or two this may be relatively efficient plan. It is more likely you sould see table B full scanned and the result feed into a hash join, but I have seen the plan you mention.
Back before hash joins were introduced with 7.3 (if my memory is correct) you would see sort/merge joins used more often than you do now. Generally speaking no index on the join conditions would exist for this option to be chosen.
If you really want to know why and sometimes what the optimizer is going to do buy Jonathan Lewis's book Cost-Based Oracle Fundamentals. If explains the optimizer in more depth than any other source I know of.
HTH -- Mark D Powell --

Difference between merge-Not matched and left outer join

Why should Merge-Not Matched be used instead of left outer join? I believe both will enable comparison of 2 tables. So what is the difference. Please advice.
mayooran99

MERGE is way to encapsulate all conditions within single statement
The equivalent implementation using join would require three different statements
1 UPDATE using INNER JOIN
1 INSERT using LEFT JOIN
and 1 DELETE using LEFT JOIN in reverse order
Both approaches work fine
so all that you need to do is left join operation to find difference you can use either
But MERGE has one additional advantage in case you need to get output from MERGE and use it for further manipulation like further insert to child table
I've explained it here
http://visakhm.blogspot.in/2014/09/t-sql-tips-multifaceted-merge-statement.html
Please Mark This As Answer if it solved your issue
Please Vote This As Helpful if it helps to solve your issue
Visakh
My Wiki User Page
My MSDN Page
My Personal Blog
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Popup LOV fails in firefox when using an outer join!!!

I have a popup lov which contains at least 2 outer joins in my query. The popup renders fine in IE but i get the error message:
"Popup List of Values query is invalid, a display and a return value are needed, the column names need to be different"
when launching the popup from Firefox (1.5.0.2)
Anyone got any idea why this works in IE but fails in Firefox?
Cheers
Duncan

Hello,
Duncan If you'll run your example code on SQL*Plus, you'll see that for department "OPERATIONS" there is no returned value. This could happen with outer join. The problem can be with the way FF is interpreting this non-value. I didn't try it my self, but maybe if you'll use display null value with your LOV, it will solve the problem. Another possible option is to use NVL() on the returned value.
Chris Some of the Apex team members, like Carl, are using FF as their main browser. There are some compatibility issues with the last version of FF, but from that, to your conclusion of Apex only support IE, there's a long road.
Regards,
Arie.

Why is Discoverer adding outer joins?

Hi,
I have set up standard joins (i.e. no outer joins) between one master and two detail folders in the Admin. For some reason when I create a report using the three folders, Discoverer is making them outer joins. Note: This query will cause a fan trap but there is a business reason for doing so (disable fan trap detection is checked). I'm using Plus/Web for the report.
Why is Discoverer adding outer joins?
Thanks, Andrew
This is what I expect (note one master joined to two details):
SELECT
O125508.BUSINESS_TRANSACTION_CODE,
O141221.SOURCE,
O141221.AMOUNT
FROM IRIS.IRS_ACQUIRED_INFO_V O125508,
IRIS.IRS_FUNDINGS_V O141221,
IRIS.IRS_FUNDING_SELECTIONS_V O144361
WHERE ( ( O125508.BUSINESS_TRANSACTION_ID = O141221.BUSINESS_TRANSACTION_ID )
AND ( O125508.BUSINESS_TRANSACTION_ID = O144361.BUSINESS_TRANSACTION_ID )
AND ( O144361.SOURCE = :"Source" )
AND ( O125508.BUSINESS_TRANSACTION_CODE = :"Business Transaction Code" )
This is what Discoverer is generating (note duplicate masters {IRS_ACQUIRED_INFO_V} with outer joins):
SELECT
O125509.BUSINESS_TRANSACTION_CODE,
O141221.SOURCE,
O141221.AMOUNT
FROM IRIS.IRS_ACQUIRED_INFO_V O125508,
IRIS.IRS_FUNDINGS_V O141221,
IRIS.IRS_ACQUIRED_INFO_V O125509,
IRIS.IRS_FUNDING_SELECTIONS_V O144361
WHERE ( ( O125509.BUSINESS_TRANSACTION_ID = O125508.BUSINESS_TRANSACTION_ID ) )
AND ( O125508.BUSINESS_TRANSACTION_ID = O141221.BUSINESS_TRANSACTION_ID(+) )
AND ( O125509.BUSINESS_TRANSACTION_ID = O144361.BUSINESS_TRANSACTION_ID(+) )
AND ( O144361.SOURCE(+) = :"Source" )
AND ( O125509.BUSINESS_TRANSACTION_CODE = :"Business Transaction Code" )
Edited by: cfandrew on Mar 26, 2009 12:36 PM

Rod,
You’re correct in that the “source” field in the query (aka: select portion) is different than the “source” field in the condition - but this is on purpose.
Here is a good analogy. Department has many Employees. The business question is to give me all employees in Andy’s Dept (but you don't know what department Andy is in, so you have to have the query reverse engineer Andy's department and then go back and get all the employees in that department).
The raw query/data without the condition causes a fan trap and looks like this:
select d.dept_name, e1.emp_name, e2.emp_name
from dept d
,emp e1
,emp e2
where d.dept_id = e1.dept_id
and d.dept_id = e2.dept_id
Dept Name....Emp Name 1....Emp_Name 2
Services.....Joe....................Joe
Services.....Joe....................Jane
Services.....Jane..................Joe
Services.....Jane..................Jane
IT.............Andy.................Andy
IT.............Andy.................Sara
IT.............Sara..................Andy
IT.............Sara..................Sara
Billing.........Bill.....................Bill
And this is what we want:
select d.dept_name, e2.emp_name
from dept d
,emp e1
,emp e2
where d.dept_id = e1. dept_id
and d.dept_id = e2. dept_id
and e1.emp_name = 'Andy'
Dept Name...Emp_Name 2
IT...............Andy
IT...............Sara
And this is what Discoverer is providing:
select d2.dept_name, e2.emp_name
from dept d1
,dept d2
,emp e1
,emp e2
where d2.dept_id = d1.dept_id
and d1.dept_id = e1.dept_id(+)
and d2.dept_id = e2.dept_id(+)
and e1.emp_name(+) = 'Andy'
Dept Name....Emp_Name 2
Service..........Joe
Service..........Jane
IT.................Andy
IT.................Sara
Billing.............Bill
Also, DisableAutoOuterJoinsOnFilters is set to 1.
Thanks for your help!
Andy

My iPhone 5 keeps on dying when it says I have around 15% battery left. Anything I can do sort This out?

My iPhone 5 keeps on dying when it says I have around 15% battery left. Anything I can do sort This out?

Check this answer by Lawrence Finch in this post: Re: iPhone 5 battery dies at 5 percent
Lawrence Finch NYC Area
Re: iPhone 5 battery dies at 5 percent
19.11.2013 01:23 (in response to woo671)
There are two common causes for this issue; either the battery gauge needs recalibration, or the battery is dying. The one you can fix is to recalibrate:
When it shuts off charge for just a minute or two, then restart (hold HOME and SLEEP until an Apple logo appears). Deliberately run the battery down until the phone shuts off at 1%. If it shuts off above 1% repeat the above until you get to 1%. Then charge for 4 hours with the wall charger without using the phone. This process will recalibrate the battery gauge.
To prevent this from happening again about once a month run the battery all the way down to 1%, then continue until the phone shuts off. Apple recommends this in their battery help article, but they don't say why you should do it. The have some hokum about "keeping the electrons moving." Honestly! The iPad battery tip gives the correct reason.

I log out properly but when i log back in a message appears basically saying it cant open my page due another one being not closed properly before. WHY?

I log out correctly every time making sure all windows are closed but every time i log back in a window appears saying "well this is embarrassing, we are having trouble opening your page (or something close to that, i cant remember the exact words) then at the bottom it says"this is usually due to a window being open (or close to that) then it asks me if i want to close or restore the session and it has a list of the last 2 pages i opened.
But i ALWAYS close them before logging out. Why does it keep doing this? Do we have a clever hacker or something?

hello lexi, this is currently a problem in firefox when you first close all open firefox windows and then close the application afterwards - the bug should be addressed in a later version of firefox.
as a workaround in the meanwhile you could close firefox (through firefox > quit) while the browser window is still running or try this: enter about:config into the firefox location bar (confirm the info message in case it shows up) & search for the preference named '''browser.sessionstore.resume_from_crash'''. double-click it and change its value to '''false'''.

Sort-Merge outer join, why? when?

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