Why does my IN operator change the datatype

Question

Hi
This doesn't make any sense, but i'm hoping there's an obvious answer which you guys have seen a million times before.
I have this criteria in my WHERE clause
AND rpg_id = (SELECT rpg_id
                                         FROM integration.rep_elig_groups
                                        WHERE pel_id IN(34))because of this clause no results are return in my query. However if i use a to_number function like this:
AND rpg_id = to_number(SELECT rpg_id
                                         FROM integration.rep_elig_groups
                                        WHERE pel_id IN(34))OR
AND to_char(rpg_id) = (SELECT rpg_id
                                         FROM integration.rep_elig_groups
                                        WHERE pel_id IN(34))i get the expected results returned.
The sub query:-
SELECT rpg_id
                                         FROM integration.rep_elig_groups
                                        WHERE pel_id IN(34)returns the value 226. rpg_id in this table is a NUMBER datatype. As is rpg_id in the original outer query.
I looked at synonyms, views, and other objects it might be using for the rep_elig_groups table, but there are none.
Then i tried changing the IN operator for an EQUALS operator and would you believe it, it worked.
AND rpg_id = (SELECT rpg_id
                                         FROM integration.rep_elig_groups
                                        WHERE pel_id IN(34))can someone please explain what ORACLE is thinking here!!!
Many thanks
Edited by: tri_harder on Dec 9, 2008 4:48 PM missed the closing bracket in the final piece of code!
Edited by: tri_harder on Dec 10, 2008 8:44 AM

Answer 1

I ran the expain plans in TOAD for both queries, with the only difference changing the operator from IN to =. I'm very surprised there is such a difference between the two!!
SELECT   tim_id,
              rpg_id,
                             ROUND(SUM(retail_value), 2) retail_value,
                             ROUND(SUM(salesidx), 2) salesidx,
                             ROUND(SUM(VALUE), 2) VALUE,
                             ROUND(SUM(bva_salesidx), 2) bva_salesidx,
                             ROUND(SUM(bva_value), 2) bva_value,
                             ROUND(SUM(bva_retail_value), 2) bva_retail_value
                        FROM ms_stats_ol_ms
                       WHERE 1 = 1
                         AND fmt_id IN(SELECT ID
                                         FROM formats
                                        WHERE car_id = 0 OR 0 = 0)
                         AND fmt_id NOT IN(
                               SELECT fmt.ID
                                 FROM formats fmt,
                                      class_formats clf
                                WHERE fmt.ID = clf.fmt_id
                                  AND clf.cla_id IN(3, 6)
                                  AND fmt.car_id = 2)
                         AND cla_id = 3
                         AND rpg_id = (SELECT rpg_id
                                         FROM rep_elig_groups
                                        WHERE pel_id IN(34))
                         AND tim_id BETWEEN 4985 AND 5418
                    GROUP BY tim_id, rpg_idSo this is my original query that returned no results and produced the following Explain Plan:-
Plan
SELECT STATEMENT  ALL_ROWSCost: 10,842  Bytes: 1,505  Cardinality: 35                                          
     17 HASH GROUP BY  Cost: 10,842  Bytes: 1,505  Cardinality: 35                                     
          16 HASH JOIN  Cost: 10,836  Bytes: 1,587,345  Cardinality: 36,915                                
               1 TABLE ACCESS FULL TABLE INTEGRATION.FORMATS Cost: 2  Bytes: 90  Cardinality: 15                           
               15 HASH JOIN RIGHT ANTI  Cost: 10,833  Bytes: 1,456,912  Cardinality: 39,376                           
                    6 VIEW VIEW SYS.VW_NSO_1 Cost: 4  Bytes: 6  Cardinality: 2                      
                         5 HASH JOIN  Cost: 4  Bytes: 24  Cardinality: 2                 
                              2 TABLE ACCESS FULL TABLE INTEGRATION.FORMATS Cost: 2  Bytes: 12  Cardinality: 2            
                              4 INLIST ITERATOR            
                                   3 INDEX RANGE SCAN INDEX (UNIQUE) INTEGRATION.CLF_PK Cost: 1  Bytes: 60  Cardinality: 10       
                    14 TABLE ACCESS BY INDEX ROWID TABLE CHARTDEV.MS_STATS_OL_MS Cost: 10,829  Bytes: 1,530,034  Cardinality: 45,001                      
                         13 BITMAP CONVERSION TO ROWIDS                 
                              12 BITMAP AND            
                                   8 BITMAP INDEX SINGLE VALUE INDEX (BITMAP) CHARTDEV.MSST_OL_MS_RPG_ID_I      
                                        7 INDEX FAST FULL SCAN INDEX (UNIQUE) INTEGRATION.REG_PK Cost: 2  Bytes: 6  Cardinality: 1 
                                   10 BITMAP MERGE       
                                        9 BITMAP INDEX RANGE SCAN INDEX (BITMAP) CHARTDEV.MSST_OL_MS_TIM_ID_I
                                   11 BITMAP INDEX SINGLE VALUE INDEX (BITMAP) CHARTDEV.MSST_OL_MS_CLA_ID_I      The following script has the very small change of the operator changed from IN to =
SELECT   tim_id,
              rpg_id,
                             ROUND(SUM(retail_value), 2) retail_value,
                             ROUND(SUM(salesidx), 2) salesidx,
                             ROUND(SUM(VALUE), 2) VALUE,
                             ROUND(SUM(bva_salesidx), 2) bva_salesidx,
                             ROUND(SUM(bva_value), 2) bva_value,
                             ROUND(SUM(bva_retail_value), 2) bva_retail_value
                        FROM ms_stats_ol_ms
                       WHERE 1 = 1
                         AND fmt_id IN(SELECT ID
                                         FROM formats
                                        WHERE car_id = 0 OR 0 = 0)
                         AND fmt_id NOT IN(
                               SELECT fmt.ID
                                 FROM formats fmt,
                                      class_formats clf
                                WHERE fmt.ID = clf.fmt_id
                                  AND clf.cla_id IN(3, 6)
                                  AND fmt.car_id = 2)
                         AND cla_id = 3
                         AND rpg_id IN (SELECT rpg_id
                                         FROM rep_elig_groups
                                        WHERE pel_id IN(34))
                         AND tim_id BETWEEN 4985 AND 5418
                    GROUP BY tim_id, rpg_idAnd this returned the expected results and produced the following Explain plan:-
Plan
SELECT STATEMENT  ALL_ROWSCost: 10,996  Bytes: 1,610  Cardinality: 35                                                    
     30 TEMP TABLE TRANSFORMATION                                               
          10 LOAD AS SELECT SYS.SYS_TEMP_0FD9D6614_166B4444                                         
               9 MERGE JOIN CARTESIAN  Cost: 6  Bytes: 570  Cardinality: 30                                     
                    5 VIEW VIEW SYS.VW_NSO_1 Cost: 4  Bytes: 26  Cardinality: 2                                
                         4 HASH JOIN  Cost: 4  Bytes: 24  Cardinality: 2                           
                              1 TABLE ACCESS FULL TABLE INTEGRATION.FORMATS Cost: 2  Bytes: 12  Cardinality: 2                      
                              3 INLIST ITERATOR                      
                                   2 INDEX RANGE SCAN INDEX (UNIQUE) INTEGRATION.CLF_PK Cost: 1  Bytes: 60  Cardinality: 10                 
                    8 BUFFER SORT  Cost: 6  Bytes: 90  Cardinality: 15                                
                         7 TABLE ACCESS BY INDEX ROWID TABLE INTEGRATION.FORMATS Cost: 1  Bytes: 90  Cardinality: 15                           
                              6 INDEX UNIQUE SCAN INDEX (UNIQUE) INTEGRATION.FMT_PK Cost: 0  Cardinality: 1                      
          29 HASH GROUP BY  Cost: 10,990  Bytes: 1,610  Cardinality: 35                                          
               28 HASH JOIN  Cost: 10,989  Bytes: 4,600  Cardinality: 100                                     
                    11 TABLE ACCESS FULL TABLE (TEMP) SYS.SYS_TEMP_0FD9D6614_166B4444 Cost: 2  Bytes: 180  Cardinality: 30                                
                    27 HASH JOIN RIGHT SEMI  Cost: 10,987  Bytes: 34,280  Cardinality: 857                                
                         12 INDEX FAST FULL SCAN INDEX (UNIQUE) INTEGRATION.REG_PK Cost: 2  Bytes: 6  Cardinality: 1                           
                         26 TABLE ACCESS BY INDEX ROWID TABLE CHARTDEV.MS_STATS_OL_MS Cost: 10,984  Bytes: 1,310,574  Cardinality: 38,546                           
                              25 BITMAP CONVERSION TO ROWIDS                      
                                   24 BITMAP AND                 
                                        16 BITMAP MERGE            
                                             15 BITMAP KEY ITERATION       
                                                  13 INDEX FAST FULL SCAN INDEX (UNIQUE) INTEGRATION.REG_PK Cost: 2  Bytes: 6  Cardinality: 1 
                                                  14 BITMAP INDEX RANGE SCAN INDEX (BITMAP) CHARTDEV.MSST_OL_MS_RPG_ID_I
                                        18 BITMAP MERGE            
                                             17 BITMAP INDEX RANGE SCAN INDEX (BITMAP) CHARTDEV.MSST_OL_MS_TIM_ID_I      
                                        22 BITMAP MERGE            
                                             21 BITMAP KEY ITERATION       
                                                  19 TABLE ACCESS FULL TABLE (TEMP) SYS.SYS_TEMP_0FD9D6614_166B4444 Cost: 2  Bytes: 13  Cardinality: 1 
                                                  20 BITMAP INDEX RANGE SCAN INDEX (BITMAP) CHARTDEV.MSST_OL_MS_FMT_ID_I
                                        23 BITMAP INDEX SINGLE VALUE INDEX (BITMAP) CHARTDEV.MSST_OL_MS_CLA_ID_I           Can anybody suggest what's going on?? Why do i get results with one and not the other!!
Edited by: tri_harder on Dec 10, 2008 10:00 AM
altered the first query to change the IN operator to =