单项选择题

A UDT is a data type which:（）

A.must contain unique values.
B.cannot be CAST to other data types.
C.is created using the CREATE DISTINCT command.
D.contains a value that was automatically calculated from values in other columns.

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单项选择题Which of the following DB2 data types has a fixed length?（）

A.XML
B.BLOB
C.DOUBLE
D.DBCLOB

单项选择题Which of the following actions may cause a trigger to be fired?（）

A.DROP
B.ALTER
C.DELETE
D.ROLLBACK

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A.A check constraint on the EMPLOYEE table
B.A unique constraint on the EMPLOYEE table WORKDEPT column
C.A foreign key reference from the DEPARTMENT tables DEPTNO column to the WORKDEPT column of the EMPLOYEE table
D.A foreign key reference from the EMPLOYEE tables WORKDEPT column to the DEPTNO column of the DEPARTMENT table

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A.Unique
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C.Referential
D.Informational

单项选择题A view is created with the following statement:CREATE VIEW v1 AS SELECT col1, col2, col3 FROM t1 WHERE col4 > 1000 ; When will DB2 access the data from table T1 for view V1?（）

A.When view V1 is created
B.Each time the REFRESH VIEW v1 statement is executed
C.Each time an SQL statement is executed against view V1
D.Only the first time an SQL statement is executed against view V1