Examine the Exhibit1 to view the structure of an indexes for the EMPLOYEES table. Examine the query: SQL> SELECT * FROM employees WHERE employees_id IN (7876, 7900, 7902); EMPLOYEE_ID is a primary…

Question

Exhibit

Options

• AThe query uses an index skip scan on the EMP_EMP_ID_PK index to fetch the rows.
• BThe query uses the INLIST ITERATOR operator to iterate over the enumerated value list, and values
• CThe query uses the INLIST ITERATOR operator to iterate over the enumerated value list, and values
• DThe query uses the INLIST ITERATOR operator to iterate over the enumerated value list, and values
• EThe query uses a fast full index scan on the EMP_EMP_ID_PK index fetch the rows.

• A
  13% (8)
• B
  77% (48)
• C
  5% (3)
• D
  3% (2)
• E
  2% (1)

Explanation

How the CBO Evaluates IN-List Iterators The IN-list iterator is used when a query contains an IN clause with values. The execution plan is identical to what would result for a statement with an equality clause instead of IN except for one additional step. That extra step occurs when the IN-list iterator feeds the equality clause with unique values from the IN-list. Both of the statements in Example 2-1 and Example 2-1 are equivalent and produce the same Example 2-1 IN-List Iterators Initial Statement SELECT header_id, line_id, revenue_amount FROM so_lines_all WHERE header_id IN (1011,1012,1013); SELECT header_id, line_id, revenue_amount FROM so_lines_all WHERE header_id = 1011 OR header_id = 1012 OR header_id = 1013; ------------------------------------------------- SELECT STATEMENT TABLE ACCESS BY INDEX ROWID SO_LINES_ALL INDEX RANGE SCAN SO_LINES_N1

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