'HASH GROUP BY' and 'SORT GROUP BY' 11.2.0.2

Question

deleting this thread..
Edited by: OraDBA02 on Oct 3, 2012 2:35 PM

Answer 1

select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
PL/SQL Release 11.2.0.2.0 - Production
CORE 11.2.0.2.0 Production
TNS for Linux: Version 11.2.0.2.0 - Production
NLSRTL Version 11.2.0.2.0 - Production
Optimizer parameter
NAME TYPE VALUE
optimpeek_user_binds boolean FALSE
filesystemio_options string setall
object_cache_optimal_size integer 102400
optimizer_capture_sql_plan_baselines boolean FALSE
optimizer_dynamic_sampling integer 2
optimizer_features_enable string 11.2.0.2
optimizer_index_caching integer 0
optimizer_index_cost_adj integer 100
optimizer_mode string ALL_ROWS
optimizer_secure_view_merging boolean TRUE
optimizer_use_invisible_indexes boolean FALSE
optimizer_use_pending_statistics boolean FALSE
optimizer_use_sql_plan_baselines boolean FALSE
db_file_multiblock_read_count integer 128
optimizer_index_caching integer 0
optimizer_index_cost_adj integer 100
SQL
SELECT sum(this_.AMOUNT) as y0_, count(this_.GC_ID) as y1_,count(distinct this_.GC_ID) as y2_, this_.GC_TRANSACTION_TYPE_ID as y3_
from GC_TRANSACTIONS this_ where this_.MARKETPLACE_ID=:1 and this_.CUSTOMER_ID=:2 and this_.EXTERNAL_GC_TRANSACTION_ID=:3
group by this_.GC_TRANSACTION_TYPE_ID;
Indexes and Histograms
INDEX_NAME LAST_ANALYZED COLUMN_NAME COLUMN_POSITION NUM_ROWS BLEVEL CLUSTERING_FACTOR DESCEND
I_GCT_CUSMKTLSTUPD 17-jul-2012:00:15:09 CUSTOMER_ID 1 222812460 3 150983660 ASC
MARKETPLACE_ID 2 3 150983660 ASC
GC_TRANSACTION_TYPE_ID 3 3 150983660 ASC
I_GCT_EXT_GC_TRANS_ID_EXE 17-jul-2012:00:17:35 EXTERNAL_GC_TRANSACTION_ID 1 234832560 3 165680180 ASC
C_ID
EXTERNAL_GC_EXECUTION_ID 2 3 165680180 ASC
Histograms
COLUMN_NAME NUM_DISTINCT NUM_NULLS LAST_ANALYZED SAMPLE_SIZE AVG_COL_LEN HISTOGRAM
COLUMN_NAME NUM_DISTINCT NUM_NULLS LAST_ANALYZED SAMPLE_SIZE AVG_COL_LEN HISTOGRAM
EXTERNAL_GC_EXECUTION_I 21657463 54047480 24.Jul.12/00:21:28 8788182 12 HEIGHT BALANCED
D
EXTERNAL_GC_TRANSACTION 20790576 0 24.Jul.12/00:21:28 11481216 18 HEIGHT BALANCED
_ID
CUSTOMER_ID 5130572 0 24.Jul.12/00:21:28 11483246 7 HEIGHT BALANCED
MARKETPLACE_ID 6 0 24.Jul.12/00:21:28 11482295 4 FREQUENCY
GC_TRANSACTION_TYPE_ID 21 0 24.Jul.12/00:21:28 11483039 3 FREQUENCY
GC_TRANSACTION_ID 229686260 0 24.Jul.12/00:21:28 11484313 8 NONE
Histograms distibution for MARKTEPLACE_ID
Enter value for column_name: MARKETPLACE_ID
COLUMN_NAME ENDPOINT_VALUE CUMMULATIVE_FREQUENCY FREQUENCY ENDPOINT_ACTUAL_VALU
MARKETPLACE_ID 3 6543166 6543166
MARKETPLACE_ID 4 11041781 4498615
MARKETPLACE_ID 5 11459282 417501
MARKETPLACE_ID 35691 11469536 10254
MARKETPLACE_ID 44551 11475336 5800
MARKETPLACE_ID 78931 11482295 6959
6 rows selected.
CBO switches between two plans
plan-1
Plan hash value: 2380563624
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | | | 13 (100)| |
| 1 | HASH GROUP BY | | 1 | 42 | 13 (8)| 00:00:01 |
| 2 | VIEW | VW_DAG_0 | 1 | 42 | 13 (8)| 00:00:01 |
| 3 | HASH GROUP BY | | 1 | 43 | 13 (8)| 00:00:01 |
|* 4 | TABLE ACCESS BY INDEX ROWID| GC_TRANSACTIONS | 1 | 43 | 12 (0)| 00:00:01 |
|* 5 | INDEX RANGE SCAN | I_GCT_EXT_GC_TRANS_ID_EXEC_ID | 11 | | 4 (0)| 00:00:01 |
Predicate Information (identified by operation id):
4 - filter(("THIS_"."CUSTOMER_ID"=:2 AND "THIS_"."MARKETPLACE_ID"=:1))
5 - access("THIS_"."EXTERNAL_GC_TRANSACTION_ID"=:3)
Bind (child_curosr=1)
select SQL_ID,CHILD_NUMBER,HASH_VALUE,NAME,DATATYPE,WAS_CAPTURED,LAST_CAPTURED,VALUE_STRING from V$SQL_BIND_CAPTURE where SQL_ID='&sql_id'
order by LAST_CAPTURED;
Enter value for sql_id: 1hc1r8qubfdnh
1hc1r8qubfdnh 1 3031905936 :1 2 YES 24.Jul.12/00:52:29 3
1hc1r8qubfdnh 1 3031905936 :2 2 YES 24.Jul.12/00:52:29 535098352
1hc1r8qubfdnh 1 3031905936 :3 1 YES 24.Jul.12/00:52:29 203-2351701-6925919
Plan-2
Bind (child_curosr=6)
Plan hash value: 700639342
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | | | 13 (100)| |
| 1 | SORT GROUP BY | | 1 | 43 | 13 (8)| 00:00:01 |
|* 2 | TABLE ACCESS BY INDEX ROWID| GC_TRANSACTIONS | 1 | 43 | 12 (0)| 00:00:01 |
|* 3 | INDEX RANGE SCAN | I_GCT_EXT_GC_TRANS_ID_EXEC_ID | 11 | | 4 (0)| 00:00:01 |
Predicate Information (identified by operation id):
2 - filter(("THIS_"."CUSTOMER_ID"=:2 AND "THIS_"."MARKETPLACE_ID"=:1))
3 - access("THIS_"."EXTERNAL_GC_TRANSACTION_ID"=:3)
bind values
select SQL_ID,CHILD_NUMBER,HASH_VALUE,NAME,DATATYPE,WAS_CAPTURED,LAST_CAPTURED,VALUE_STRING from V$SQL_BIND_CAPTURE where SQL_ID='&sql_id'
order by LAST_CAPTURED;
Enter value for sql_id: 1hc1r8qubfdnh
1hc1r8qubfdnh 6 3031905936 :1 2 YES 24.Jul.12/03:06:04 5
1hc1r8qubfdnh 6 3031905936 :2 2 YES 24.Jul.12/03:06:04 1278126152
1hc1r8qubfdnh 6 3031905936 :3 1 YES 24.Jul.12/03:06:04 171-5012459-0045134
Why is CBO using two different 'HASH GROUP BY' with view 'VW_DAG_0' in first plan ?
Is that due to difference in MARKETPLACE_ID =4 And 5 ?