| p; 0 sorts (memory)
0 sorts (disk)
1003 rows processed
SQL> select * from unionvsor /*2nd test*/
2 where b = 1 or a = 1003 ;
1003 rows selected.
Execution Plan
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE
1 0 CONCATENATION
2 1 TABLE ACCESS (BY INDEX ROWID) OF ''''UNIONVSOR''''
3 2 INDEX (RANGE SCAN) OF ''''UA'''' (NON-UNIQUE)
4 1 TABLE ACCESS (BY INDEX ROWID) OF ''''UNIONVSOR''''
5 4 INDEX (RANGE SCAN) OF ''''UB'''' (NON-UNIQUE)
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
143 consistent gets
0 physical reads
0 redo size
63749 bytes sent via SQL*Net to client
7751 bytes received via SQL*Net from client
68 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1003 rows processed
SQL> select * from unionvsor /*3rd test*/
2 where a = 1003
3 union
4 select * from unionvsor
5 where b = 1;
1003 rows selected.
Execution Plan
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE
1 0 SORT (UNIQUE)
2 1 UNION-ALL
3 2 TABLE ACCESS (BY INDEX ROWID) OF ''''UNIONVSOR''''
4 3 INDEX (RANGE SCAN) OF ''''UA'''' (NON-UNIQUE)
5 2 TABLE ACCESS (BY INDEX ROWID) OF ''''UNIONVSOR''''
6 5 INDEX (RANGE SCAN) OF ''''UB'''' (NON-UNIQUE)
Statistics
----------------------------------------------------------
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