Help to understand the explain plan

Question

Hi, Everyone,
i have query :
INSERT INTO ICM_UPSEL_1_ALL
select  a.customer_no,a.pr_code_bbl,min(b.pr_code_pmm) pr_code_pmm,a.score,a.price_diff,a.flag
from ICM_UPSEL_MIN_PRDIFF_1 a, icm_pre b
where a.customer_no = b.customer_no
and a.pr_code_bbl=b.pr_code_bbl
and a.score = b.score
and a.flag = b.flag
and a.price_diff = b.price_diff
and b.price_diff > 0
and b.score >=0.5
and b.flag = 1
and b.price_diff >  0 and b.price_diff <= 10
group by  a.customer_no,a.pr_code_bbl,a.score,a.price_diff,a.flag
This query is running in a pl/sql procedure.  The explain plan for this query is :
Plan hash value: 3124235498
| Id  | Operation                       | Name                           | Rows  | Bytes | Cost (%CPU)| Time     |
|   0 | INSERT STATEMENT                |                                |     1 |   143 |     4  (25)| 00:00:01 |
|   1 |  LOAD TABLE CONVENTIONAL        | ICM_UPSEL_1_ALL        |       |       |            |          |
|   2 |   HASH GROUP BY                 |                                |     1 |   143 |     4  (25)| 00:00:01 |
|   3 |    NESTED LOOPS                 |                                |       |       |            |          |
|   4 |     NESTED LOOPS                |                                |     1 |   143 |     3   (0)| 00:00:01 |
|*  5 |      TABLE ACCESS BY INDEX ROWID| ICM_UPSEL_MIN_PRDIFF_1 |     1 |    65 |     1   (0)| 00:00:01 |
|*  6 |       INDEX RANGE SCAN          | MPD_1_FLAG_IDX                 |     1 |       |     1   (0)| 00:00:01 |
|*  7 |      INDEX RANGE SCAN           | ICM_PRE_FLAG_IDX               |     1 |       |     2   (0)| 00:00:01 |
|*  8 |     TABLE ACCESS BY INDEX ROWID | ICM_PRE                |     1 |    78 |     2   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   5 - filter("A"."PRICE_DIFF">0 AND "A"."SCORE">=0.5 AND "A"."PRICE_DIFF"<=10)
   6 - access("A"."FLAG"=1)
   7 - access("B"."FLAG"=1)
   8 - filter("B"."PRICE_DIFF"<=10 AND "B"."SCORE">=0.5 AND "B"."PRICE_DIFF">0 AND
              "A"."CUSTOMER_NO"="B"."CUSTOMER_NO" AND "A"."PR_CODE_BBL"="B"."PR_CODE_BBL" AND "A"."SCORE"="B"."SCORE"
              AND "A"."PRICE_DIFF"="B"."PRICE_DIFF")
This query is running for 10 hours now and no result yet.  Could anyone please help me where is going wrong... why is it taking so much time to insert the data...
The number of rows in ICM_UPSEL_MIN_PRDIFF_1 : 84,858
The number of rows in icm_pre :  455,500,944
All the columns are indexed.
My database version is 11.1.0.6 running on windows server 2003 R2.
Thanks in advance

Answer 1

Hi, Nikolay,
Please see the results below;
SELECT * FROM DBA_TAB_COL_STATISTICS
WHERE OWNER = 'SAST' AND TABLE_NAME = 'ICM_UPSEL_MIN_PRDIFF_1' AND COLUMN_NAME = 'FLAG';
TABLE_NAME
COLUMN_NAME
NUM_DISTINCT
LOW_VALUE
HIGH_VALUE
DENSITY
NUM_NULLS
NUM_BUCKETS
LAST_ANALYZED
SAMPLE_SIZE
GLOBAL_STATS
USER_STATS
AVG_COL_LEN
HISTOGRAM
SAST    ICM_UPSEL_MIN_PRDIFF_1    FLAG    1    C102    C102    0.00000584543291182618    0    1    16/07/13 10:01:42    5544    YES    NO    3    FREQUENCY
SELECT * FROM DBA_TAB_STATISTICS WHERE OWNER = 'SAST' AND TABLE_NAME = 'ICM_UPSEL_MIN_PRDIFF_1';
TABLE_NAME
PARTITION_NAME
PARTITION_POSITION
SUBPARTITION_NAME
SUBPARTITION_POSITION
OBJECT_TYPE
NUM_ROWS
BLOCKS
EMPTY_BLOCKS
AVG_SPACE
CHAIN_CNT
AVG_ROW_LEN
AVG_SPACE_FREELIST_BLOCKS
NUM_FREELIST_BLOCKS
AVG_CACHED_BLOCKS
AVG_CACHE_HIT_RATIO
SAMPLE_SIZE
LAST_ANALYZED
GLOBAL_STATS
USER_STATS
STATTYPE_LOCKED
STALE_STATS
SAST    ICM_UPSEL_MIN_PRDIFF_1 
TABLE    84858    874    0    0    0    62    0    0 
84858    16/07/13 10:02:00    YES    NO 
NO
Thanks & Regards
Su