Sql run faster using pipe ( | ) ... ???

Question

Hello all,
I have this sql which runs after with the pipes ( | ). below is original sql (from and where clause)
which takes about 2mins to run.....and the other query with pipes (|) and +0 added to the from cluase
runs like in 6secs.....and i wanted to know why the difference ?? what exactly does the pipes do and the
+0 does ??? as its a big difference ?? This was tuned by one of our SR dba...so wanted to know what does
the pipe do that makes the sql so much faster ?
original sql
FROM ((SAMPLE SAMPLE
       INNER JOIN TEST TEST
          ON SAMPLE.SAMPLE_NUMBER = TEST.SAMPLE_NUMBER)
       INNER JOIN SAMPLE ORIGINAL_SAMPLE
          ON SAMPLE.ORIGINAL_SAMPLE = ORIGINAL_SAMPLE.SAMPLE_NUMBER)
       INNER JOIN ANALYSIS ANALYSIS
          ON (TEST.ANALYSIS = ANALYSIS.NAME)
             AND (TEST.VERSION = ANALYSIS.VERSION)
WHERE (ANALYSIS.ANALYSIS_TYPE = 'INORGANIC')
   AND (TEST.STATUS IN ('I', 'C', 'P'))
   AND (SAMPLE.STANDARD = 'F')
   AND (SAMPLE.SAMPLE_NUMBER > 0
        AND (ANALYSIS.X_DATA_TYPE <> 'SUMM'
             OR ANALYSIS.X_DATA_ANALYSIS IS NULL)) sql using pipe and +0
  FROM ((SAMPLE SAMPLE
       INNER JOIN TEST TEST
          ON SAMPLE.SAMPLE_NUMBER = TEST.SAMPLE_NUMBER + 0)
       INNER JOIN SAMPLE ORIGINAL_SAMPLE
          ON SAMPLE.ORIGINAL_SAMPLE = ORIGINAL_SAMPLE.SAMPLE_NUMBER + 0),
       ANALYSIS ANALYSIS
WHERE ANALYSIS.ANALYSIS_TYPE || '' = 'INORGANIC'
   AND TEST.STATUS IN ('I', 'C', 'P')
   AND SAMPLE.STANDARD = 'F'
   AND SAMPLE.SAMPLE_NUMBER > 0
   AND (ANALYSIS.X_DATA_TYPE < 'SUMM'
         OR ANALYSIS.X_DATA_TYPE > 'SUMM'
         OR ANALYSIS.X_DATA_ANALYSIS IS NULL)
   AND ANALYSIS.NAME = TEST.ANALYSIS || ''
   AND ANALYSIS.VERSION = TEST.VERSION

Answer 1

this is the original plan
Plan hash value: 192553293
| Id  | Operation                      | Name           | Rows  | Bytes |TempSpc| Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT               |                | 24263 |  3601K|       | 20979   (2)| 00:04:12 |
|*  1 |  HASH JOIN                     |                | 24263 |  3601K|  3656K| 20979   (2)| 00:04:12 |
|*  2 |   HASH JOIN                    |                | 24263 |  3364K|  2848K| 17399   (2)| 00:03:29 |
|*  3 |    HASH JOIN                   |                | 26698 |  2529K|       | 13784   (2)| 00:02:46 |
|*  4 |     TABLE ACCESS BY INDEX ROWID| ANALYSIS       |   164 |  7216 |       |    47   (0)| 00:00:01 |
|*  5 |      INDEX RANGE SCAN          | IDX_ANALYSIS_1 |   189 |       |       |     1   (0)| 00:00:01 |
|*  6 |     TABLE ACCESS FULL          | TEST           |   800K|    40M|       | 13730   (2)| 00:02:45 |
|*  7 |    TABLE ACCESS FULL           | SAMPLE         |   119K|  5268K|       |  3150   (2)| 00:00:38 |
|   8 |   TABLE ACCESS FULL            | SAMPLE         |   239K|  2341K|       |  3148   (2)| 00:00:38 |
---------------------------------------------------------------------------------------------------------and this is the one of using pipe
Plan hash value: 2901999266
| Id  | Operation                       | Name        | Rows  | Bytes |TempSpc| Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT                |             | 25502 |  3785K|       |   158K  (1)| 00:31:47 |
|*  1 |  HASH JOIN                      |             | 25502 |  3785K|  3840K|   158K  (1)| 00:31:47 |
|*  2 |   HASH JOIN                     |             | 25502 |  3536K|  2992K|   155K  (1)| 00:31:04 |
|*  3 |    HASH JOIN                    |             | 28061 |  2658K|       |   151K  (1)| 00:30:21 |
|*  4 |     TABLE ACCESS FULL           | ANALYSIS    |   172 |  7568 |       |    56   (2)| 00:00:01 |
|   5 |     INLIST ITERATOR             |             |       |       |       |            |          |
|*  6 |      TABLE ACCESS BY INDEX ROWID| TEST        |   800K|    40M|       |   151K  (1)| 00:30:20 |
|*  7 |       INDEX RANGE SCAN          | TEST_STATUS |   828K|       |       |  2218   (1)| 00:00:27 |
|*  8 |    TABLE ACCESS FULL            | SAMPLE      |   119K|  5268K|       |  3150   (2)| 00:00:38 |
|   9 |   TABLE ACCESS FULL             | SAMPLE      |   239K|  2341K|       |  3148   (2)| 00:00:38 |
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