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单选题 QUESTION 178 Choose the best answer. Examine this statement: SELECT 1 AS id, 'John' AS first_name, NULL AS commission FROM DUAL INTERSECT SELECT 1, 'John' ,NULL FROM DUAL ORDER BY 3; What is returned upon execution?

A、 2 rows
B、 1 row.
C、 0 rows
D、 an error

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单选题 QUESTION 40 The EMPLOYEES table contains columns EMP_ID of data type NUMBER and HIRE_DATE of data type DATE. You want to display the date of the first Monday after the completion of six months since hiring. The NLS_TERRITORY parameter is set to AMERICA in the session and , therefore, Sunday is the first day on the wee. Which query can be used?

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单选题 QUESTION 9 What is true about non-equijoin statement performance?

A、 The Oracle join syntax performs less well than the sQI:1999 compliant ANSI join syntax.
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