DB2 9.0 GROUPING SETS & ROLLUP & CUBE 比较
GROUP BY GROUPING SETS((),())--(NESTED FLAG,GROUP BY UNION ALL)
GROUPING SETS((A,B,C))
GROUPING SETS(A,(B,C))
GROUPING SETS(A,B,C)
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GROUPING SETS(A),GROUPING SETS(B),GROUPING SETS(C)
GROUPING SETS(A),GROUPING SETS((B,C))
GROUPING SETS(A),GROUPING SETS(B,C)
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GROUP BY (),GROUPING SETS()
GROUP BY A,B,GROUPING SETS(B,C)
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ROLLUP
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GROUP BY ROLLUP(A,(B,C))
GROUP BY ROLLUP(A),ROLLUP(B,C)
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CUBE
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GROUP BY CUBE(A,B,C)
GROUP BY CUBE(A,(B,C))
GROUP BY CUBE(A,B),CUBE(B,C)