Why two different explain plan for same objects?
Believe or not there are two different databases, one for processing and one for reporting, plan is show different for same query. Table structure and indexes are same. It's 11G
Thanks
Good explain plan .. works fine..
Plan
SELECT STATEMENT ALL_ROWSCost: 12,775 Bytes: 184 Cardinality: 1
27 SORT UNIQUE Cost: 12,775 Bytes: 184 Cardinality: 1
26 NESTED LOOPS
24 NESTED LOOPS Cost: 12,774 Bytes: 184 Cardinality: 1
22 HASH JOIN Cost: 12,772 Bytes: 178 Cardinality: 1
20 NESTED LOOPS SEMI Cost: 30 Bytes: 166 Cardinality: 1
17 NESTED LOOPS Cost: 19 Bytes: 140 Cardinality: 1
14 NESTED LOOPS OUTER Cost: 16 Bytes: 84 Cardinality: 1
11 VIEW DSSADM. Cost: 14 Bytes: 37 Cardinality: 1
10 NESTED LOOPS
8 NESTED LOOPS Cost: 14 Bytes: 103 Cardinality: 1
6 NESTED LOOPS Cost: 13 Bytes: 87 Cardinality: 1
3 INLIST ITERATOR
2 TABLE ACCESS BY INDEX ROWID TABLE DSSODS.DRV_PS_JOB_FAMILY_TBL Cost: 10 Bytes: 51 Cardinality: 1
1 INDEX RANGE SCAN INDEX DSSODS.DRV_PS_JOB_FAMILY_TBL_CL_SETID Cost: 9 Cardinality: 1
5 TABLE ACCESS BY INDEX ROWID TABLE DSSADM.DIM_JOBCODE Cost: 3 Bytes: 36 Cardinality: 1
4 INDEX RANGE SCAN INDEX DSSADM.STAN_JB_FN_IDX Cost: 2 Cardinality: 1
7 INDEX UNIQUE SCAN INDEX (UNIQUE) DSSODS.DRV_PS_JOBCODE_TBL_SEQ_KEY_RPT Cost: 0 Cardinality: 1
9 TABLE ACCESS BY INDEX ROWID TABLE DSSODS.DRV_PS_JOBCODE_TBL_RPT Cost: 1 Bytes: 16 Cardinality: 1
13 TABLE ACCESS BY INDEX ROWID TABLE DSSODS.DRV_PSXLATITEM_RPT Cost: 2 Bytes: 47 Cardinality: 1
12 INDEX RANGE SCAN INDEX DSSODS.PK_DRV_RIXLATITEM_RPT Cost: 1 Cardinality: 1
16 TABLE ACCESS BY INDEX ROWID TABLE DSSADM.DIM_JOBCODE Cost: 3 Bytes: 56 Cardinality: 1
15 INDEX RANGE SCAN INDEX DSSADM.DIM_JOBCODE_EXPDT1 Cost: 2 Cardinality: 1
19 TABLE ACCESS BY INDEX ROWID TABLE DSSODS.DRV_PS_JOB_RPT Cost: 11 Bytes: 438,906 Cardinality: 16,881
18 INDEX RANGE SCAN INDEX DSSODS.DRV_PS_JOB_JOBCODE_RPT Cost: 2 Cardinality: 8
21 INDEX FAST FULL SCAN INDEX (UNIQUE) DSSADM.Z_PK_JOBCODE_PROMPT_TBL Cost: 12,699 Bytes: 66,790,236 Cardinality: 5,565,853
23 INDEX RANGE SCAN INDEX DSSADM.DIM_PERSON_EMPL_RCD_SEQ_KEY Cost: 1 Cardinality: 1
25 TABLE ACCESS BY INDEX ROWID TABLE DSSADM.DIM_PERSON_EMPL_RCD Cost: 2 Bytes: 6 Cardinality: 1 This bad plan ... show merge join cartesian and full table ..
Plan
SELECT STATEMENT ALL_ROWSCost: 3,585 Bytes: 237 Cardinality: 1
26 SORT UNIQUE Cost: 3,585 Bytes: 237 Cardinality: 1
25 NESTED LOOPS SEMI Cost: 3,584 Bytes: 237 Cardinality: 1
22 NESTED LOOPS Cost: 3,573 Bytes: 211 Cardinality: 1
20 MERGE JOIN CARTESIAN Cost: 2,864 Bytes: 70,446 Cardinality: 354
17 NESTED LOOPS
15 NESTED LOOPS Cost: 51 Bytes: 191 Cardinality: 1
13 NESTED LOOPS OUTER Cost: 50 Bytes: 180 Cardinality: 1
10 HASH JOIN Cost: 48 Bytes: 133 Cardinality: 1
6 NESTED LOOPS
4 NESTED LOOPS Cost: 38 Bytes: 656 Cardinality: 8
2 TABLE ACCESS BY INDEX ROWID TABLE REPORT2.DIM_JOBCODE Cost: 14 Bytes: 448 Cardinality: 8
1 INDEX RANGE SCAN INDEX REPORT2.STAN_PROM_JB_IDX Cost: 6 Cardinality: 95
3 INDEX RANGE SCAN INDEX REPORT2.SETID_JC_IDX Cost: 2 Cardinality: 1
5 TABLE ACCESS BY INDEX ROWID TABLE REPORT2.DIM_JOBCODE Cost: 3 Bytes: 26 Cardinality: 1
9 INLIST ITERATOR
8 TABLE ACCESS BY INDEX ROWID TABLE REPORT2.DRV_PS_JOB_FAMILY_TBL Cost: 10 Bytes: 51 Cardinality: 1
7 INDEX RANGE SCAN INDEX REPORT2.DRV_PS_JOB_FAMILY_TBL_CL_SETID Cost: 9 Cardinality: 1
12 TABLE ACCESS BY INDEX ROWID TABLE REPORT2.DRV_PSXLATITEM_RPT Cost: 2 Bytes: 47 Cardinality: 1
11 INDEX RANGE SCAN INDEX REPORT2.PK_DRV_RIXLATITEM_RPT Cost: 1 Cardinality: 1
14 INDEX UNIQUE SCAN INDEX (UNIQUE) REPORT2.DRV_PS_JOBCODE_TBL_SEQ_KEY_RPT Cost: 0 Cardinality: 1
16 TABLE ACCESS BY INDEX ROWID TABLE REPORT2.DRV_PS_JOBCODE_TBL_RPT Cost: 1 Bytes: 11 Cardinality: 1
19 BUFFER SORT Cost: 2,863 Bytes: 4,295,552 Cardinality: 536,944
18 TABLE ACCESS FULL TABLE REPORT2.DIM_PERSON_EMPL_RCD Cost: 2,813 Bytes: 4,295,552 Cardinality: 536,944
21 INDEX RANGE SCAN INDEX (UNIQUE) REPORT2.Z_PK_JOBCODE_PROMPT_TBL Cost: 2 Bytes: 12 Cardinality: 1
24 TABLE ACCESS BY INDEX ROWID TABLE REPORT2.DRV_PS_JOB_RPT Cost: 11 Bytes: 1,349,920 Cardinality: 51,920
23 INDEX RANGE SCAN INDEX REPORT2.DRV_PS_JOB_JOBCODE_RPT Cost: 2 Cardinality: 8
user550024 wrote:
I am really surprise that the stat for good sql are little old. I just computed the states of bad sql so they are uptodate..
There is something terribly wrong..Not necessarily. Just using the default stats collection I've seen a few cases of things suddenly going wrong. As the data increases, it gets closer to an edge case where the inadequacy of the statistics convinces the optimizer to do a wrong plan. To fix, I could just go into dbconsole, set the stats back to a time when they worked, and locked them. In most cases it's definitely better to figure out what is really going on, though, to give the optimizer better information to work with. Aside from the value of learning how to do it, for some cases it's not so simple. Also, many think the default settings of the database statistic collection may be wrong in general (in 10.2.x, at least). So much depends on your application and data that you can't make too many generalizations. You have to look at the evidence and figure it out. There is still a steep learning curve for the tools to look at the evidence. People are here to help with that.
Most of the time it works better than a dumb rule based optimizer, but at the cost of a few situations where people are smarter than computers. It's taken a lot of years to get to this point.
Similar Messages
-
Differenet Explain Plan for Same Query
DB Version : 11.2.0.3
OS Version : AIX 6
I have two Queries ( The Difference between Them Only 940 and 584 ) When I Generate Explain Plan Different Output Why ? Why CPU time is Different Each Time
First Query Statement :
INSERT INTO TempSearchResult (t_aid,
t_umidl,
t_umidh,
X_CREA_DATE_TIME_MESG)
SELECT z.aid,
z.mesg_s_umidl,
z.mesg_s_umidh,
z.mesg_crea_date_time
FROM ( SELECT m.aid,
m.mesg_s_umidl,
m.mesg_s_umidh,
m.mesg_crea_date_time
FROM RSMESG_ESIDE m
WHERE 1 = 1
AND m.mesg_crea_date_time BETWEEN TO_DATE (
'20120131 10:00:00',
'YYYYMMDD HH24:MI:SS')
AND TO_DATE (
'20120131 13:00:00',
'YYYYMMDD HH24:MI:SS')
AND m.mesg_frmt_name = 'Swift'
AND m.mesg_sender_x1 = 'SOGEFRPPXXX'
AND m.mesg_nature = 'FINANCIAL_MSG'
AND m.mesg_type LIKE '950'
ORDER BY mesg_crea_date_time) z
WHERE ROWNUM <= 5000
Explain Plan for First Query :
PLAN_TABLE_OUTPUT
Plan hash value: 3901722890
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Pstart| Pstop |
| 0 | INSERT STATEMENT | | 2866 | 134K| 197 (3)| 00:00:03 | | |
| 1 | LOAD TABLE CONVENTIONAL | TEMPSEARCHRESULT | | | | | | |
|* 2 | COUNT STOPKEY | | | | | | | |
| 3 | VIEW | | 2866 | 134K| 197 (3)| 00:00:03 | | |
|* 4 | SORT ORDER BY STOPKEY | | 2866 | 333K| 197 (3)| 00:00:03 | | |
| 5 | NESTED LOOPS | | 2866 | 333K| 196 (2)| 00:00:03 | | |
PLAN_TABLE_OUTPUT
| 6 | NESTED LOOPS | | 1419 | 148K| 196 (2)| 00:00:03 | | |
|* 7 | HASH JOIN | | 1419 | 141K| 196 (2)| 00:00:03 | | |
| 8 | NESTED LOOPS | | 91 | 1911 | 2 (0)| 00:00:01 | | |
| 9 | TABLE ACCESS BY INDEX ROWID | SUSER | 1 | 10 | 1 (0)| 00:00:01 | | |
|* 10 | INDEX UNIQUE SCAN | IX_SUSER | 1 | | 0 (0)| 00:00:01 | | |
|* 11 | INDEX FULL SCAN | PK_SUNITUSERGROUP | 91 | 1001 | 1 (0)| 00:00:01 | | |
| 12 | PARTITION RANGE SINGLE | | 1450 | 114K| 193 (2)| 00:00:03 | 2 | 2 |
|* 13 | TABLE ACCESS BY LOCAL INDEX ROWID| RMESG | 1450 | 114K| 193 (2)| 00:00:03 | 2 | 2 |
|* 14 | INDEX SKIP SCAN | IX_RMESG | 415 | | 14 (15)| 00:00:01 | 2 | 2 |
|* 15 | INDEX UNIQUE SCAN | PK_SMSGUSERGROUP | 1 | 5 | 0 (0)| 00:00:01 | | |
|* 16 | INDEX UNIQUE SCAN | PK_SBICUSERGROUP | 2 | 24 | 0 (0)| 00:00:01 | | |
PLAN_TABLE_OUTPUT
PLAN_TABLE_OUTPUT
Predicate Information (identified by operation id):
2 - filter(ROWNUM<=5000)
4 - filter(ROWNUM<=5000)
7 - access("X_INST0_UNIT_NAME"="UNIT")
10 - access("SUSER"."USERNAME"="SIDE"."GETMYUSER"())
11 - access("SUSER"."GROUPID"="SUNITUSERGROUP"."GROUPID")
filter("SUSER"."GROUPID"="SUNITUSERGROUP"."GROUPID")
PLAN_TABLE_OUTPUT
13 - filter("RMESG"."MESG_SENDER_X1"='SOGEFRPPXXX' AND "RMESG"."MESG_NATURE"='FINANCIAL_MSG' AND
"RMESG"."MESG_FRMT_NAME"='Swift')
14 - access("RMESG"."MESG_CREA_DATE_TIME">=TO_DATE(' 2012-01-31 10:00:00', 'syyyy-mm-dd hh24:mi:ss') AND
"RMESG"."MESG_TYPE"='950' AND "RMESG"."MESG_CREA_DATE_TIME"<=TO_DATE(' 2012-01-31 13:00:00', 'syyyy-mm-dd hh24:mi:ss'))
filter("RMESG"."MESG_TYPE"='950')
15 - access("X_CATEGORY"="CATEGORY" AND "SUSER"."GROUPID"="SMSGUSERGROUP"."GROUPID")
16 - access("X_OWN_LT"="BICCODE" AND "SUSER"."GROUPID"="SBICUSERGROUP"."GROUPID")
40 rows selected.
Second query
INSERT INTO TempSearchResult (t_aid,
t_umidl,
t_umidh,
X_CREA_DATE_TIME_MESG)
SELECT z.aid,
z.mesg_s_umidl,
z.mesg_s_umidh,
z.mesg_crea_date_time
FROM ( SELECT m.aid,
m.mesg_s_umidl,
m.mesg_s_umidh,
m.mesg_crea_date_time
FROM RSMESG_ESIDE m
WHERE 1 = 1
AND m.mesg_crea_date_time BETWEEN TO_DATE (
'20120117 10:00:00',
'YYYYMMDD HH24:MI:SS')
AND TO_DATE (
'20120117 13:00:00',
'YYYYMMDD HH24:MI:SS')
AND m.mesg_frmt_name = 'Swift'
AND m.mesg_sender_x1 = 'SOGEFRPPGSS'
AND m.mesg_nature = 'FINANCIAL_MSG'
AND m.mesg_type LIKE '548'
ORDER BY mesg_crea_date_time) z
WHERE ROWNUM <= 5000
Explain Plan For Second Query :
PLAN_TABLE_OUTPUT
Plan hash value: 4106071428
| Id | Operation | Name | Rows | Bytes |TempSpc| Cost (%CPU)| Time | Pstart| Pstop |
| 0 | INSERT STATEMENT | | 1073 | 51504 | | 2622 (1)| 00:00:32 | | |
| 1 | LOAD TABLE CONVENTIONAL | TEMPSEARCHRESULT | | | | | | | |
|* 2 | COUNT STOPKEY | | | | | | | | |
| 3 | VIEW | | 1073 | 51504 | | 2622 (1)| 00:00:32 | | |
|* 4 | SORT ORDER BY STOPKEY | | 1073 | 124K| | 2622 (1)| 00:00:32 | | |
| 5 | NESTED LOOPS | | 1073 | 124K| | 2621 (1)| 00:00:32 | | |
PLAN_TABLE_OUTPUT
| 6 | NESTED LOOPS | | 531 | 56817 | | 2621 (1)| 00:00:32 | | |
| 7 | NESTED LOOPS | | 531 | 54162 | | 2621 (1)| 00:00:32 | | |
| 8 | NESTED LOOPS | | 543 | 49413 | | 2621 (1)| 00:00:32 | | |
| 9 | TABLE ACCESS BY INDEX ROWID | SUSER | 1 | 10 | | 1 (0)| 00:00:01 | | |
|* 10 | INDEX UNIQUE SCAN | IX_SUSER | 1 | | | 0 (0)| 00:00:01 | | |
| 11 | PARTITION RANGE SINGLE | | 543 | 43983 | | 2621 (1)| 00:00:32 | 2 | 2 |
|* 12 | TABLE ACCESS BY LOCAL INDEX ROWID| RMESG | 543 | 43983 | | 2621 (1)| 00:00:32 | 2 | 2 |
| 13 | BITMAP CONVERSION TO ROWIDS | | | | | | | | |
| 14 | BITMAP AND | | | | | | | | |
| 15 | BITMAP CONVERSION FROM ROWIDS | | | | | | | | |
|* 16 | INDEX RANGE SCAN | IX_SENDER | 25070 | | | 894 (1)| 00:00:11 | 2 | 2 |
PLAN_TABLE_OUTPUT
| 17 | BITMAP CONVERSION FROM ROWIDS | | | | | | | | |
| 18 | SORT ORDER BY | | | | 408K| | | | |
|* 19 | INDEX RANGE SCAN | IX_RMESG | 25070 | | | 1405 (1)| 00:00:17 | 2 | 2 |
|* 20 | INDEX UNIQUE SCAN | PK_SUNITUSERGROUP | 1 | 11 | | 0 (0)| 00:00:01 | | |
|* 21 | INDEX UNIQUE SCAN | PK_SMSGUSERGROUP | 1 | 5 | | 0 (0)| 00:00:01 | | |
|* 22 | INDEX UNIQUE SCAN | PK_SBICUSERGROUP | 2 | 24 | | 0 (0)| 00:00:01 | | |
Predicate Information (identified by operation id):
PLAN_TABLE_OUTPUT
2 - filter(ROWNUM<=5000)
4 - filter(ROWNUM<=5000)
10 - access("SUSER"."USERNAME"="SIDE"."GETMYUSER"())
12 - filter("RMESG"."MESG_NATURE"='FINANCIAL_MSG' AND "RMESG"."MESG_FRMT_NAME"='Swift')
16 - access("RMESG"."MESG_SENDER_X1"='SOGEFRPPGSS')
19 - access("RMESG"."MESG_CREA_DATE_TIME">=TO_DATE(' 2012-01-17 10:00:00', 'syyyy-mm-dd hh24:mi:ss') AND
"RMESG"."MESG_TYPE"='548' AND "RMESG"."MESG_CREA_DATE_TIME"<=TO_DATE(' 2012-01-17 13:00:00', 'syyyy-mm-dd hh24:mi:ss'))
filter("RMESG"."MESG_TYPE"='548' AND "RMESG"."MESG_CREA_DATE_TIME"<=TO_DATE(' 2012-01-17 13:00:00', 'syyyy-mm-dd
hh24:mi:ss') AND "RMESG"."MESG_CREA_DATE_TIME">=TO_DATE(' 2012-01-17 10:00:00', 'syyyy-mm-dd hh24:mi:ss'))
20 - access("X_INST0_UNIT_NAME"="UNIT" AND "SUSER"."GROUPID"="SUNITUSERGROUP"."GROUPID")
21 - access("X_CATEGORY"="CATEGORY" AND "SUSER"."GROUPID"="SMSGUSERGROUP"."GROUPID")
PLAN_TABLE_OUTPUT
22 - access("X_OWN_LT"="BICCODE" AND "SUSER"."GROUPID"="SBICUSERGROUP"."GROUPID")
45 rows selected.
Table Structure TEMPSEARCHRESULT
CREATE GLOBAL TEMPORARY TABLE TEMPSEARCHRESULT
T_AID NUMBER(3),
T_UMIDL NUMBER(10),
T_UMIDH NUMBER(10),
X_CREA_DATE_TIME_MESG DATE
ON COMMIT PRESERVE ROWS
NOCACHE;
CREATE INDEX SIDE.TEMP_SEARCH_INDEX ON SIDE.TEMPSEARCHRESULT
(T_AID, T_UMIDL, T_UMIDH, X_CREA_DATE_TIME_MESG);Again Thank you For your amazing Answer.
For indexes it's a balance. Check this query which is Simple
Select * from RMESGI generated Explain Plan for it to see effect of indexes .
PLAN_TABLE_OUTPUT
Plan hash value: 1686435785
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | Pstart| Pstop |
| 0 | SELECT STATEMENT | | 11M| 8920M| 376K (1)| 01:15:20 | | |
| 1 | PARTITION RANGE ALL| | 11M| 8920M| 376K (1)| 01:15:20 | 1 | 12 |
| 2 | TABLE ACCESS FULL | RMESG | 11M| 8920M| 376K (1)| 01:15:20 | 1 | 12 |
---------------------------------------------------------------------------------------------1:15:20 For table access and Full Scan Also , I generate new Indexes on the table like the following
CREATE TABLE RMESG(
aid NUMBER(3) NOT NULL,
mesg_s_umidl NUMBER(10) NOT NULL,
mesg_s_umidh NUMBER(10) NOT NULL,
mesg_validation_requested CHAR(18) NOT NULL,
mesg_validation_passed CHAR(18) NOT NULL,
mesg_class CHAR(16) NOT NULL,
mesg_is_text_readonly NUMBER(1) NOT NULL,
mesg_is_delete_inhibited NUMBER(1) NOT NULL,
mesg_is_text_modified NUMBER(1) NOT NULL,
mesg_is_partial NUMBER(1) NOT NULL,
mesg_crea_mpfn_name CHAR(24) NOT NULL,
mesg_crea_rp_name CHAR(24) NOT NULL,
mesg_crea_oper_nickname CHAR(151) NOT NULL,
mesg_crea_date_time DATE NOT NULL,
mesg_mod_oper_nickname CHAR(151) NOT NULL,
mesg_mod_date_time DATE NOT NULL,
mesg_frmt_name VARCHAR2(17) NOT NULL,
mesg_nature CHAR(14) NOT NULL,
mesg_sender_x1 CHAR(11) NOT NULL,
mesg_sender_corr_type VARCHAR2(24) NOT NULL,
mesg_uumid VARCHAR2(50) NOT NULL,
mesg_uumid_suffix NUMBER(10) NOT NULL,
x_own_lt CHAR(8) NOT NULL,
x_inst0_unit_name VARCHAR2(32) default 'NONE' NOT NULL,
x_category CHAR(1) NOT NULL,
archived NUMBER(1) NOT NULL,
restored NUMBER(1) NOT NULL,
mesg_related_s_umid CHAR(16) NULL,
mesg_status CHAR(12) NULL,
mesg_crea_appl_serv_name CHAR(24) NULL,
mesg_verf_oper_nickname CHAR(151) NULL,
mesg_data_last NUMBER(10) NULL,
mesg_token NUMBER(10) NULL,
mesg_batch_reference VARCHAR2(46) NULL,
mesg_cas_sender_reference VARCHAR2(40) NULL,
mesg_cas_target_rp_name VARCHAR2(20) NULL,
mesg_ccy_amount VARCHAR2(501) NULL,
mesg_copy_service_id VARCHAR2(4) NULL,
mesg_data_keyword1 VARCHAR2(80) NULL,
mesg_data_keyword2 VARCHAR2(80) NULL,
mesg_data_keyword3 VARCHAR2(80) NULL,
mesg_delv_overdue_warn_req NUMBER(1) NULL,
mesg_fin_ccy_amount VARCHAR2(24) NULL,
mesg_fin_value_date CHAR(6) NULL,
mesg_is_live NUMBER(1) NULL,
mesg_is_retrieved NUMBER(1) NULL,
mesg_mesg_user_group VARCHAR2(24) NULL,
mesg_network_appl_ind CHAR(3) NULL,
mesg_network_delv_notif_req NUMBER(1) NULL,
mesg_network_obso_period NUMBER(10) NULL,
mesg_network_priority CHAR(12) NULL,
mesg_possible_dup_creation VARCHAR2(8) NULL,
mesg_receiver_alia_name VARCHAR2(32) NULL,
mesg_receiver_swift_address CHAR(12) NULL,
mesg_recovery_accept_info VARCHAR2(80) NULL,
mesg_rel_trn_ref VARCHAR2(80) NULL,
mesg_release_info VARCHAR2(32) NULL,
mesg_security_iapp_name VARCHAR2(80) NULL,
mesg_security_required NUMBER(1) NULL,
mesg_sender_x2 VARCHAR2(21) NULL,
mesg_sender_x3 VARCHAR2(21) NULL,
mesg_sender_x4 VARCHAR2(21) NULL,
mesg_sender_branch_info VARCHAR2(71) NULL,
mesg_sender_city_name VARCHAR2(36) NULL,
mesg_sender_ctry_code VARCHAR2(3) NULL,
mesg_sender_ctry_name VARCHAR2(71) NULL,
mesg_sender_institution_name VARCHAR2(106) NULL,
mesg_sender_location VARCHAR2(106) NULL,
mesg_sender_swift_address CHAR(12) NULL,
mesg_sub_format VARCHAR2(6) NULL,
mesg_syntax_table_ver VARCHAR2(8) NULL,
mesg_template_name VARCHAR2(32) NULL,
mesg_trn_ref VARCHAR2(16) NULL,
mesg_type CHAR(3) NULL,
mesg_user_issued_as_pde NUMBER(1) NULL,
mesg_user_priority_code CHAR(4) NULL,
mesg_user_reference_text VARCHAR2(30) NULL,
mesg_zz41_is_possible_dup NUMBER(1) NULL,
x_fin_ccy CHAR(3) NULL,
x_fin_amount NUMBER(21,4) NULL,
x_fin_value_date DATE NULL,
x_fin_ocmt_ccy CHAR(3) NULL,
x_fin_ocmt_amount NUMBER(21,4) NULL,
x_receiver_x1 CHAR(11) NULL,
x_receiver_x2 VARCHAR2(21) NULL,
x_receiver_x3 VARCHAR2(21) NULL,
x_receiver_x4 VARCHAR2(21) NULL,
last_update DATE NULL,
set_id NUMBER(10) NULL,
mesg_requestor_dn VARCHAR2(101) NULL,
mesg_service VARCHAR2(31) NULL,
mesg_request_type VARCHAR2(31) NULL,
mesg_identifier VARCHAR2(31) NULL,
mesg_xml_query_ref1 VARCHAR2(101) NULL,
mesg_xml_query_ref2 VARCHAR2(101) NULL,
mesg_xml_query_ref3 VARCHAR2(101) NULL,
mesg_appl_sender_reference VARCHAR2(51) NULL,
mesg_payload_type VARCHAR2(31) NULL,
mesg_sign_digest_reference VARCHAR2(41) NULL,
mesg_sign_digest_value VARCHAR2(51) NULL,
mesg_use_pki_signature NUMBER(1) NULL
PARTITION BY RANGE(MESG_CREA_DATE_TIME) (
PARTITION SIDE_MIN VALUES LESS THAN (TO_DATE(20000101, 'YYYYMMDD')) TABLESPACE TBS_SIDEDB_DA_01);
CREATE UNIQUE INDEX SIDE.IX_PK_RMESG on SIDE.RMESG (AID, MESG_S_UMIDH, MESG_S_UMIDL, MESG_CREA_DATE_TIME) LOCAL;
ALTER TABLE SIDE.RMESG ADD CONSTRAINT IX_PK_RMESG PRIMARY KEY (AID, MESG_S_UMIDH, MESG_S_UMIDL, MESG_CREA_DATE_TIME) USING INDEX SIDE.IX_PK_RMESG;
CREATE INDEX SIDE.ix_rmesg_cassender ON SIDE.rmesg (MESG_CAS_SENDER_REFERENCE) LOCAL;
CREATE INDEX SIDE.ix_rmesg_creationdate ON SIDE.rmesg (MESG_CREA_DATE_TIME) LOCAL;
CREATE INDEX SIDE.ix_rmesg_trnref ON SIDE.rmesg (MESG_TRN_REF) LOCAL;
CREATE INDEX SIDE.ix_rmesg_uumid ON SIDE.rmesg (MESG_UUMID, MESG_UUMID_SUFFIX) LOCAL;
CREATE INDEX SIDE.IX_UNIT_NAME_RMESG on RMESG(mesg_crea_date_time,X_INST0_UNIT_NAME) LOCAL;
CREATE INDEX SIDE.IX_RMESG on RMESG(mesg_crea_date_time ,mesg_type,x_fin_ccy) LOCAL;
CREATE INDEX SIDE.IX_NAME_FORMAT_TYPE_RMESG on RMESG(mesg_frmt_name,mesg_sub_format,mesg_type,mesg_crea_date_time ) LOCAL;same Explain Plan Same Result .
I always remember TOM Quote "full scans are not evil, indexes are not good"
Which Mean Something Wrong Goes with Indexes , the partition depend on MESG_CREA_DATE_TIME Column I create Index for this column but same explain plan Appear every time. With Same Time.
Thank you
Osama -
Different 'execution plans' for same sql in 10R2
DB=10.2.0.5
OS=RHEL 3
Im not sure of this, but seeing different plans for same SQL.
select sql_text from v$sqlarea where sql_id='92mb4z83fg4st'; <---TOP SQL from AWR
SELECT /*+ OPAQUE_TRANSFORM */ "ENDUSERID","LASTLOGINATTEMPTTIMESTAMP","LOGINSOURCECD","LOGINSUCCESSFLG",
"ENDUSERLOGINATTEMPTHISTORYID","VERSION_NUM","CREATEDATE"
FROM "BOMB"."ENDUSERLOGINATTEMPTHISTORY" "ENDUSERLOGINATTEMPTHISTORY";
SQL> set autotrace traceonly
SQL> SELECT /*+ OPAQUE_TRANSFORM */ "ENDUSERID","LASTLOGINATTEMPTTIMESTAMP","LOGINSOURCECD","LOGINSUCCESSFLG",
"ENDUSERLOGINATTEMPTHISTORYID","VERSION_NUM","CREATEDATE"
FROM "BOMB"."ENDUSERLOGINATTEMPTHISTORY" "ENDUSERLOGINATTEMPTHISTORY"; 2 3
1822203 rows selected.
Execution Plan
Plan hash value: 568996432
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1803K| 75M| 2919 (2)| 00:00:36 |
| 1 | TABLE ACCESS FULL| ENDUSERLOGINATTEMPTHISTORY | 1803K| 75M| 2919 (2)| 00:00:36 |
Statistics
0 recursive calls
0 db block gets
133793 consistent gets
0 physical reads
0 redo size
76637183 bytes sent via SQL*Net to client
1336772 bytes received via SQL*Net from client
121482 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1822203 rows processed
===================================== another plan ===============
SQL> select * from TABLE(dbms_xplan.display_awr('92mb4z83fg4st'));
15 rows selected.
Execution Plan
Plan hash value: 3015018810
| Id | Operation | Name |
| 0 | SELECT STATEMENT | |
| 1 | COLLECTION ITERATOR PICKLER FETCH| DISPLAY_AWR |
Note
- rule based optimizer used (consider using cbo)
Statistics
24 recursive calls
24 db block gets
49 consistent gets
0 physical reads
0 redo size
1529 bytes sent via SQL*Net to client
492 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
15 rows processed
=========second one shows only 15 rows...
Which one is correct ?Understood, second plan is for self 'dbms_xplan'.
Anyhow I opened a new session where I did NOT on 'auto-trace'. but plan is somewhat than the original.
SQL> /
PLAN_TABLE_OUTPUT
SQL_ID 92mb4z83fg4st
SELECT /*+ OPAQUE_TRANSFORM */ "ENDUSERID","LASTLOGINATTEMPTTIMESTAMP","LOGINSOURCECD","
LOGINSUCCESSFLG","ENDUSERLOGINATTEMPTHISTORYID","VERSION_NUM","CREATEDATE" FROM
"BOMB"."ENDUSERLOGINATTEMPTHISTORY" "ENDUSERLOGINATTEMPTHISTORY"
Plan hash value: 568996432
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
PLAN_TABLE_OUTPUT
| 0 | SELECT STATEMENT | | | | 2919 (100)| |
| 1 | TABLE ACCESS FULL| ENDUSERLOGINATTEMPTHISTORY | 1803K| 75M| 2919 (2)| 00:00:36 |
15 rows selected.
I am just wondering, which plan is the accurate and which I need to believe ? -
Different query plans for same query on same DB
Hi,
HP-Ux
Oracle Database 10.2.0.4
We are experiencing a strange issue. One of our night batch process is taking invariably more time to execute. The process does not consume time at 1 particular query. Everyday we find a new query taking more time than previous execution.
Now, when we see the explain plan while the query is executing, we see NESTED LOOP SEMI (with improper index being used). At the same time if we take the query and see the explain plan seperately, we get HASH JOIN SEMI (with proper index being used). Also, if we execute this query with the values as in procedure, it finishes within mili seconds (as it should).
The tables and indexes are analyzed everyday before the process starts.
Can anybody explain, why the same query shows two different plans at the same time ?
Thanks a lot in advance :)Aalap Sharma wrote:
HP-Ux
Oracle Database 10.2.0.4
We are experiencing a strange issue. One of our night batch process is taking invariably more time to execute. The process does not consume time at 1 particular query. Everyday we find a new query taking more time than previous execution.
Now, when we see the explain plan while the query is executing, we see NESTED LOOP SEMI (with improper index being used). At the same time if we take the query and see the explain plan seperately, we get HASH JOIN SEMI (with proper index being used). Also, if we execute this query with the values as in procedure, it finishes within mili seconds (as it should).
The tables and indexes are analyzed everyday before the process starts.
Can anybody explain, why the same query shows two different plans at the same time ?As already mentioned, you might hit typical issues in 10.2: The column workload based SIZE AUTO statistics gathering feature and/or bind variable peeking.
How do you analyze the tables and indexes before the process starts? Can you share the exact call with parameters?
Some ideas:
1. If your process is "new", then the column workload monitoring of the database might recognize the column usage pattern and generate histograms on some of your columns. It might take a while until the workload has been established so that all columns got histograms according to the workload (It needs a certain number of usages/executions before the workload is registered as relevant). Until then you might get different execution plans each time the statistics are refreshed due to new histograms being added.
2. If the default 10g statistics gathering job is active, it might gather different statistics during the night than your individual job that runs prior to the processing. This could be one possible explanation why you get different plans on the next day.
3. "Bind Variable Peeking" is possibly another issue you might run into. How do you test the query so that you get a different, well performing plan? Does your original statement use bind variables? Do you use literals to reproduce? Note that using EXPLAIN PLAN on statements involving bind variables can lie, since it doesn't perform bind variable peeking by default.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/ -
Same query is taking different times in two databses.
Both dababases are similar being refreshed from one.
Below are the the explain plan from both queries.
Can anything be conclusive from this information.
Second explain plan is for a faster execution.
SELECT STATEMENT ALL_ROWSCost: 245,393
18 PX COORDINATOR
17 PX SEND QC (RANDOM) PARALLEL_TO_SERIAL SYS.:TQ10003 Cost: 245,393 Bytes: 735,679,824 Cardinality: 8,359,998
16 HASH GROUP BY PARALLEL_COMBINED_WITH_PARENT Cost: 245,393 Bytes: 735,679,824 Cardinality: 8,359,998
15 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 198,164 Bytes: 735,679,824 Cardinality: 8,359,998
14 PX SEND HASH PARALLEL_TO_PARALLEL SYS.:TQ10002 Cost: 198,164 Bytes: 735,679,824 Cardinality: 8,359,998
13 HASH JOIN PARALLEL_COMBINED_WITH_PARENT Cost: 198,164 Bytes: 735,679,824 Cardinality: 8,359,998
4 BUFFER SORT PARALLEL_COMBINED_WITH_CHILD
3 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 15 Bytes: 129,220 Cardinality: 2,485
2 PX SEND BROADCAST PARALLEL_FROM_SERIAL SYS.:TQ10000 Cost: 15 Bytes: 129,220 Cardinality: 2,485
1 TABLE ACCESS FULL TABLE myschema.team Cost: 15 Bytes: 129,220 Cardinality: 2,485
12 TABLE ACCESS BY LOCAL INDEX ROWID TABLE PARALLEL_COMBINED_WITH_PARENT myschema.mytable Cost: 18,117 Bytes: 4,777,136 Cardinality: 183,736
11 NESTED LOOPS PARALLEL_COMBINED_WITH_PARENT Cost: 198,125 Bytes: 300,959,928 Cardinality: 8,359,998
8 BUFFER SORT PARALLEL_COMBINED_WITH_CHILD
7 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT
6 PX SEND BROADCAST PARALLEL_FROM_SERIAL SYS.:TQ10001
5 TABLE ACCESS FULL TABLE myschema.dim Cost: 12 Bytes: 450 Cardinality: 45
10 PX PARTITION RANGE ITERATOR PARALLEL_COMBINED_WITH_CHILD Cost: 38 Cardinality: 183,736 Partition #: 17
9 INDEX RANGE SCAN INDEX PARALLEL_COMBINED_WITH_PARENT myschema.IDX_TDATE_DC_FLAG Cost: 38 Cardinality: 183,736 Partition #: 17
SELECT STATEMENT CHOOSECost: 2,830
14 PX COORDINATOR
13 PX SEND QC (RANDOM) PARALLEL_TO_SERIAL SYS.:TQ10003 Cost: 2,830 Bytes: 21,327,392 Cardinality: 288,208
12 HASH GROUP BY PARALLEL_COMBINED_WITH_PARENT Cost: 2,830 Bytes: 21,327,392 Cardinality: 288,208
11 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 2,828 Bytes: 21,327,392 Cardinality: 288,208
10 PX SEND HASH PARALLEL_TO_PARALLEL SYS.:TQ10002 Cost: 2,828 Bytes: 21,327,392 Cardinality: 288,208
9 HASH JOIN BUFFERED PARALLEL_COMBINED_WITH_PARENT Cost: 2,828 Bytes: 21,327,392 Cardinality: 288,208
4 BUFFER SORT PARALLEL_COMBINED_WITH_CHILD
3 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 19 Bytes: 129,272 Cardinality: 2,486
2 PX SEND HASH PARALLEL_FROM_SERIAL SYS.:TQ10000 Cost: 19 Bytes: 129,272 Cardinality: 2,486
1 TABLE ACCESS FULL TABLE myschema.team Cost: 19 Bytes: 129,272 Cardinality: 2,486
8 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208
7 PX SEND HASH PARALLEL_TO_PARALLEL SYS.:TQ10001 Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208
6 PX BLOCK ITERATOR PARALLEL_COMBINED_WITH_CHILD Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208 Partition #: 13 Partitions accessed #1 - #5
5 MAT_VIEW REWRITE ACCESS FULL MAT_VIEW REWRITE PARALLEL_COMBINED_WITH_PARENT myschema.matv_2 Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208 Partition #: 13 Partitions accessed
Edited by: user610910 on Feb 13, 2009 5:12 AMSELECT STATEMENT CHOOSE Cost: 2,830
14 PX COORDINATOR
13 PX SEND QC (RANDOM) PARALLEL_TO_SERIAL SYS.:TQ10003 Cost: 2,830 Bytes: 21,327,392 Cardinality: 288,208
12 HASH GROUP BY PARALLEL_COMBINED_WITH_PARENT Cost: 2,830 Bytes: 21,327,392 Cardinality: 288,208
11 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 2,828 Bytes: 21,327,392 Cardinality: 288,208
10 PX SEND HASH PARALLEL_TO_PARALLEL SYS.:TQ10002 Cost: 2,828 Bytes: 21,327,392 Cardinality: 288,208
9 HASH JOIN BUFFERED PARALLEL_COMBINED_WITH_PARENT Cost: 2,828 Bytes: 21,327,392 Cardinality: 288,208
4 BUFFER SORT PARALLEL_COMBINED_WITH_CHILD
3 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 19 Bytes: 129,272 Cardinality: 2,486
2 PX SEND HASH PARALLEL_FROM_SERIAL SYS.:TQ10000 Cost: 19 Bytes: 129,272 Cardinality: 2,486
1 TABLE ACCESS FULL TABLE MYSCHEMA.TEAM Cost: 19 Bytes: 129,272 Cardinality: 2,486
8 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208
7 PX SEND HASH PARALLEL_TO_PARALLEL SYS.:TQ10001 Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208
6 PX BLOCK ITERATOR PARALLEL_COMBINED_WITH_CHILD Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208 Partition #: 13 Partitions accessed #1 - #5
5 MAT_VIEW REWRITE ACCESS FULL MAT_VIEW REWRITE PARALLEL_COMBINED_WITH_PARENT MYSCHEMA.MATVW Cost: 2,808 Bytes: 6,340,576 Cardinality: 288,208 Partition #: 13 Partitions accessed #1 - #5
SELECT STATEMENT ALL_ROWSCost: 245,393
18 PX COORDINATOR
17 PX SEND QC (RANDOM) PARALLEL_TO_SERIAL SYS.:TQ10003 Cost: 245,393 Bytes: 735,679,824 Cardinality: 8,359,998
16 HASH GROUP BY PARALLEL_COMBINED_WITH_PARENT Cost: 245,393 Bytes: 735,679,824 Cardinality: 8,359,998
15 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 198,164 Bytes: 735,679,824 Cardinality: 8,359,998
14 PX SEND HASH PARALLEL_TO_PARALLEL SYS.:TQ10002 Cost: 198,164 Bytes: 735,679,824 Cardinality: 8,359,998
13 HASH JOIN PARALLEL_COMBINED_WITH_PARENT Cost: 198,164 Bytes: 735,679,824 Cardinality: 8,359,998
4 BUFFER SORT PARALLEL_COMBINED_WITH_CHILD
3 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT Cost: 15 Bytes: 129,220 Cardinality: 2,485
2 PX SEND BROADCAST PARALLEL_FROM_SERIAL SYS.:TQ10000 Cost: 15 Bytes: 129,220 Cardinality: 2,485
1 TABLE ACCESS FULL TABLE MYSCHEMA.TEAM Cost: 15 Bytes: 129,220 Cardinality: 2,485
12 TABLE ACCESS BY LOCAL INDEX ROWID TABLE PARALLEL_COMBINED_WITH_PARENT MYSCHEMA.MY_TABLE Cost: 18,117 Bytes: 4,777,136 Cardinality: 183,736
11 NESTED LOOPS PARALLEL_COMBINED_WITH_PARENT Cost: 198,125 Bytes: 300,959,928 Cardinality: 8,359,998
8 BUFFER SORT PARALLEL_COMBINED_WITH_CHILD
7 PX RECEIVE PARALLEL_COMBINED_WITH_PARENT
6 PX SEND BROADCAST PARALLEL_FROM_SERIAL SYS.:TQ10001
5 TABLE ACCESS FULL TABLE MYSCHEMA.DIM Cost: 12 Bytes: 450 Cardinality: 45
10 PX PARTITION RANGE ITERATOR PARALLEL_COMBINED_WITH_CHILD Cost: 38 Cardinality: 183,736 Partition #: 17
9 INDEX RANGE SCAN INDEX PARALLEL_COMBINED_WITH_PARENT MYSCHEMA.MY_IDX Cost: 38 Cardinality: 183,736 Partition #: 17 I think this one looks better. -
Explain plan for same query in three databases
Hi,
We have three databases dev, uat and test, all have same init parameters and almost same data. We are running a query which runs long on dev and on uat and test it runs very fast, the explain plan on uat and test shows a cost of around 4000 but on dev the cost is 20000. Statistics were collected on three instances 2 days ago and the objects are also same.
My question is what else should I look for this optimizer behaviour? the database version is 10.2.0.3.
Please help.
Thanks
Clinuser627471 wrote:
Hi,
We have three databases dev, uat and test, all have same init parameters and almost same data. We are running a query which runs long on dev and on uat and test it runs very fast, the explain plan on uat and test shows a cost of around 4000 but on dev the cost is 20000. Statistics were collected on three instances 2 days ago and the objects are also same.
My question is what else should I look for this optimizer behaviour? the database version is 10.2.0.3.
Please help.
Thanks
Clinpost both EXPLAIN PLAN here -
Different execution plan for same query but for different condition value
Hi All,
I'm facing a strange situation where same query for different condition not working.
1--
Select top 10 * from revenuefact(nolock)
where feecode ='OW4'
2--
Select top 10 * from revenuefact(nolock)
where feecode ='BTE'
1st query is returning result easily but 2nd query is taking too long. Column
feecode has already Non-clustered index and Clustered index is also available for another col RevenueSID.
I was surprised when checked the query execution plan for both the above queries which is quite different (as per attached below). Can anyone suggest me the reason behind it.
And solution for the same. One more thing that data for feecode BTE is inserting through different source instead of others feecode and table contains more than 300 million rows.When I speak with people inside Microsoft who work with the optimizer, the refuse to accept the work "bug" when a query produces the correct result, but with a suboptimal plan. They prefer to use the word "limitation".
The limitation here is that when the optimizer compares two plans, it only looks at the estimated cost. As far as I know, it does not perform any analysis from the perspective "what if the statistics are wrong"? They do provide the hint OPTIMIZE
FOR UNKNOWN, but that does not work then there is a constant as in this case.
The optimizer will surely distinguish between TOP 10 and TOP 10000000. With the latter, you have all reason to expect a Clustered Index Scan no matter which value you search for - unless you pick a value for which the histogram indicates that there are no
rows.
Interesting enough, I was able to reproduce the situation in my Northgale database, which is an inflated version of Northwind, and where statistics should be accurate.
SELECT TOP 10 * FROM Orders WHERE EmployeeID = 8
results in a CI scan, and so does also EmployeeID = 7, and even 5. There are only 2292 rows out of a total of 344305 rows. If I try EmployeeID 808 for which there are 1797, the optimizer goes for the index seek.
Erland Sommarskog, SQL Server MVP, [email protected] -
Two different tax calculation for same material/plant/vendor key combination
Hi all,
My requirement is that in PO client needs two different percentages of calculation of VAT for same plant/vendor/material.
How can this be incorporated?
regards,
vinsHi Vinda,
Can't you use Tax Code in Purchase order and enter as the case may be
If not, please ellaborate with example
Thanks
Nishu -
Why two different URLS lead to same thread?
My action engine nugget here
http://forums.ni.com/ni/board/message?board.id=170&message.id=240328#M240328
showed up at the botom of the LV page as one ot the most Kudoed and when I hit that link it takes me to here
http://forums.ni.com/ni/board/message?message.uid=503801#U503801
THey both seem to be the same thread but different URLs. Why?
Just curious*,
Ben
* Don't expect me stop asking question now. It is way to late for that to help.
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction
Solved!
Go to Solution.Ben wrote:
http://forums.ni.com/ni/board/message?board.id=170&message.id=240328#M240328
http://forums.ni.com/ni/board/message?message.uid=503801#U503801
THey both seem to be the same thread but different URLs. Why?
I would think that the forum is just a huge database of posts with a front end that formats the pages dynamically.
Apparently, a post can be addressed either from a global ID (URL#2) or from a board/boardID (URL#1). Same difference.
LabVIEW Champion . Do more with less code and in less time . -
Can't set up two different IMAP accounts for same company
I have a new company and it requires two separate email accounts. One of the accounts works just fine, the other doesn't. I've tried support info on the mozilla site, I've tried the imapconfig.exe file, and nothing works! One of the accounts is a customer service account that needs to work just as well as the personal account for the company works.
Could you check with the company if IMAP access (supposed you are using that) or POP3 access has been enabled for that specific mailbox?
-
Same query, same dataset, same ddl setup, but wildly different explain plan
Hello o fountains of oracle knowledge!
We have a problem that caused us a full stop when rolling out a new version of our system to a customer and a whole Sunday to boot.
The scenario is as follows:
1. An previous version database schema
2. The current version database schema
3. A migration script to migrate the old schema to the new
So we perform the following migration:
1. Export the previous version database schema
2. Import into a new schema called schema_old
3. Create a new schema called schema_new
4. Run migration script which creates objects, copies data, creates indexes etc etc in schema_new
The migration runs fine in all environments (development, test and production)
In our development and test environments performance is stellar, on the customer production server the performance is terrible.
This using the exact same export file (from the production environment) and performing the exact same steps with the exact same migration script.
Database version is 10.2.0.1.0 EE on all databases. OS is Microsoft Windows Server 2003 EE SP2 on all servers.
The system is not in any sense under a heavy load (we have tested with no other load than ourselves).
Looking at the explain plan for a query that is run frequently and does not use bind variables we see wildly different explain plans.
The explain plan cost on our development and test servers is estimated to *7* for this query and there are no full table scans.
On the production server the cost is *8433* and there are two full table scans of which one is on the largest table.
We have tried to run analyse on all objects with very little effect. The plan changed very slightly, but still includes the two full table scans on the problem server and the cost is still the same.
All tables and indexes are identical (including storage options), created from the same migration script.
I am currently at loss for where to look? What can be causing this? I assume this could be caused by some parameter that is set on the server, but I don't know what to look for.
I would be very grateful for any pointers.
Thanks,
HåkonThank you for your answer.
We collected statistics only after we determined that the production server where not behaving according to expectations.
In this case we used TOAD and the tool within to collect statistics for all objects. We used 'Analyze' and 'Compute Statistics' options.
I am not an expert, so sorry if this is too naive an approach.
Here is the query:SELECT count(0)
FROM score_result sr, web_scorecard sc, product p
WHERE sr.score_final_decision like 'VENT%'
AND sc.CREDIT_APPLICATION_ID = sr.CREDIT_APPLICATION_ID
AND sc.application_complete='Y'
AND p.product = sc.web_product
AND p.inactive_product = '2' ;I use this as an example, but the problem exists for virtually all queries.
The output from the 'good' server:
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|
| 0 | SELECT STATEMENT | | 1 | 39 | 7 (0)|
| 1 | SORT AGGREGATE | | 1 | 39 | |
| 2 | NESTED LOOPS | | 1 | 39 | 7 (0)|
| 3 | NESTED LOOPS | | 1 | 30 | 6 (0)|
| 4 | TABLE ACCESS BY INDEX ROWID| SCORE_RESULT | 1 | 17 | 4 (0)|
| 5 | INDEX RANGE SCAN | SR_FINAL_DECISION_IDX | 1 | | 3 (0)|
| 6 | TABLE ACCESS BY INDEX ROWID| WEB_SCORECARD | 1 | 13 | 2 (0)|
| 7 | INDEX UNIQUE SCAN | WEB_SCORECARD_PK | 1 | | 1 (0)|
| 8 | TABLE ACCESS BY INDEX ROWID | PRODUCT | 1 | 9 | 1 (0)|
| 9 | INDEX UNIQUE SCAN | PK_PRODUCT | 1 | | 0 (0)|
---------------------------------------------------------------------------------------------The output from the 'bad' server:
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)|
| 0 | SELECT STATEMENT | | 1 | 32 | 8344 (3)|
| 1 | SORT AGGREGATE | | 1 | 32 | |
| 2 | HASH JOIN | | 10887 | 340K| 8344 (3)|
| 3 | TABLE ACCESS FULL | PRODUCT | 6 | 42 | 3 (0)|
| 4 | HASH JOIN | | 34381 | 839K| 8340 (3)|
| 5 | VIEW | index$_join$_001 | 34381 | 503K| 2193 (3)|
| 6 | HASH JOIN | | | | |
| 7 | INDEX RANGE SCAN | SR_FINAL_DECISION_IDX | 34381 | 503K| 280 (3)|
| 8 | INDEX FAST FULL SCAN| SCORE_RESULT_PK | 34381 | 503K| 1371 (2)|
| 9 | TABLE ACCESS FULL | WEB_SCORECARD | 489K| 4782K| 6137 (4)|
----------------------------------------------------------------------------------------I hope the formatting makes this readable.
Stats (from SQL Developer), good table:NUM_ROWS 489716
BLOCKS 27198
AVG_ROW_LEN 312
SAMPLE_SIZE 489716
LAST_ANALYZED 15.12.2009
LAST_ANALYZED_SINCE 15.12.2009Stats (from SQL Developer), bad table:
NUM_ROWS 489716
BLOCKS 27199
AVG_ROW_LEN 395
SAMPLE_SIZE 489716
LAST_ANALYZED 17.12.2009
LAST_ANALYZED_SINCE 17.12.2009I'm unsure what would cause the difference in average row length.
I could obviously try to tune our sql-statements to work on the server not behaving better, but I would rather understand why they are different and make sure that we can expect similar behaviour between environments.
Thank you again for trying to help me.
Håkon
Edited by: ergates on 17.des.2009 05:57
Edited by: ergates on 17.des.2009 06:02 -
Same query with different explain plans
Hi All,
I have one of the select query with different explain plans on two separate env, the query fetches the correct index on test env whereas on prod it's not fetching the same index.
The structure, indices, no. of rows are similar in CRMINFO table with up-to-date statistics.
Env Details :
OS - Sun Solaris 5.10
DB - 10.2.0.4
Init param:
Optimizer_mode = ALL_ROWS
optimizer_dynamic_sampling integer 5
optimizer_features_enable string 10.2.0.4
optimizer_index_caching integer 90
optimizer_index_cost_adj integer 30
Query :*
SELECT COUNT (*)
FROM CRMINFO
WHERE RETAILER = :1
AND STATUS = 20
AND EXC = :1
AND SUBNO IS NULL
Expain Plan (TST):
SELECT STATEMENT ALL_ROWSCost: 916 Bytes: 19 Cardinality: 1
3 SORT AGGREGATE Bytes: 19 Cardinality: 1
2 TABLE ACCESS BY INDEX ROWID TABLE TST.CRMINFO Cost: 916 Bytes: 16,663 Cardinality: 877
1 INDEX RANGE SCAN INDEX TST.CRMINFO_X1 Cost: 42 Cardinality: 12,549
Index (TST):
CRMINFO_X1(EXC, RETAILER, STATUS)
Explain Plan (PROD):
SELECT STATEMENT ALL_ROWSCost: 1,832 Bytes: 19 Cardinality: 1
3 SORT AGGREGATE Bytes: 19 Cardinality: 1
2 TABLE ACCESS BY INDEX ROWID TABLE PROD.CRMINFO Cost: 1,832 Bytes: 2,052 Cardinality: 108
1 INDEX RANGE SCAN INDEX PROD.CRMINFO_X2 Cost: 117 Cardinality: 42,519
Index (PROD):
CRMINFO_X2 (RETAILER)
How does Oracle calculates the cost and decides which index it should fetch ? Why it didn't choose the same index as of test env? How should i approach and which domains i need to dig-in to find the cause?
I did try playing with the above mentioned init parameters but it didn't help at all.
Thanks.
Regards,
~PointerPointer wrote:
Hmm, my worry is how do i force oracle to grap the proper index on prod i.e (CRMINFO_X1). I certainly believe it's a bad approach on adding a hint in the select statement and to force oralce to fetch that index.Why do you believe that, the index you mention is the "proper" index versus what Oracle is choosing? Can you prove with hinting that the "proper" index results in a faster and more efficient execution plan? If it does, then the next place I would look at is the statistics for the tables and columns of interest. From here you could try and estimate why Oracle thinks the other index is better. Another option is to run a 10053 (CBO) trace and see why Oracle thinks it is better.
I would not support a hint in a production environment, except in the most extreme cases. Usually the CBO makes the right choice, but it only can if the statistics match the distribution of data.
Refreshing the data may help me simulating the issue on TST but it wouldn't help me to understand why on prod it uses CRMINFO_X2 instead of CRMINFO_X1 which has all the three columns in the Where clause of the query.It would help because it's a test environment and you wouldn't have to do any queries directly on your production system to achieve the same results.
>
A bad thought here :( , if i create a new index by changing the column positioning say like ( RETAILER, STATUS , EXC) instead of (EXC, RETAILER, STATUS) will oracle fetch it ? or would it help in reducing the cost and cardinatlity of the select query.It's not that easy. There is a lot that goes into the cost calculation, some of that is known (through the great work by Jonathan Lewis and Richard Foote), and some of that is purely internal to Oracle. If you are more interested in the internals Cost-Based Oracle Fundamentals by Jonathan Lewis is a great book.
HTH! -
I am trying to store music for two different iPods on the same Windows 8 computer, and when I try and download content from the Cloud I get an error message. Is it possible to have two different Apple IDs on the same computer?
Unfortunately you've discovered too late how important it is to maintain an up-to-date backup of your iTunes library (and all other data of value). You could, before wiping the drive, have considered making use of a commercial data recovery service that could (albeit at considerable cost) have extracted your library from the hard disk, even if virus infected.
In the absence of that option, you will need to restore the content of your library from its original sources:
Depending on your location, you may be able to re-download any iTunes Store purchases that are still available on the Store
Likewise, most digital purchases from Amazon (including auto-rip copies of purchased CDs) should be available from the Amazon Cloud and via the Amazon Music application - the same may be true of other commercial sources for digital downloads
Content imported from your CDs will have to imported again
The specific situation that you describe regarding the music imported from your friend's external HDD suggests that either the source is badly organized and/or originates from a source other than iTunes (other media players may use alternative tags for information like artist, title, album, etc. that are not wholly consistent with how iTunes handle these). Without details of the issues you're seeing it is difficult to suggest a remedy other than going through the media album-by-album, track-by-track, and correcting the inconsistencies.
In the absence of a backup or access to the original library data there is no option other than painstakingly recreating your library as described above. As you do so, you'll now realize how important creating and maintaining backups are - in my case I have at all times three separate duplicates of my library, in two different locations, where none is ever more than a week old compared to the content of my master library. -
HT201269 Can I set up two accounts for two different iPhones on the same iTunes account. Jimmy
Hello,
CanI set up two accounts for two different iPhones on the same iTunes account. Thanks JIMMYhttp://support.apple.com/kb/ht1495
You can use the same apple id for two separate phoones to share apps/music, however you would need a separate apple id for both phone for imessage/facetime/icloud. -
Why tkprof did not show explain plan for some sql statements
Hi,
I did a trace for one of the session, hoping to find the explain plan for its tkprof. However, I only get this:
INSERT INTO AUDIT_TABLE
VALUES
( :B1 , :B2 , :B3 , :B4 , :B5 , :B6 , :B8 , :B7 )
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 3698 8.08 59.41 3348 566 19092 3698
Fetch 0 0.00 0.00 0 0 0 0
total 3699 8.08 59.42 3348 566 19092 3698
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: 30 (recursive depth: 2)
********************************************************************************Any idea why the explain plan is missing?
Also looking at the above statistics, what can I conclude?Thanks John. What's ur take on this statistics then?
call count cpu elapsed disk query current rows
Parse 0 0.00 0.00 0 0 0 0
Execute 1798 12.23 36.75 1758 5404 7418 1798
Fetch 0 0.00 0.00 0 0 0 0
total 1798 12.23 36.75 1758 5404 7418 1798
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: 30 (recursive depth: 1)
********************************************************************************
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