IBM A2090-556 問題集

質問 1：
What does the UNION operator do?
A. Combine two result sets, eliminating duplicates.
B. Combine two regular tables into one.
C. Combine two columns into one, eliminating duplicates.
D. The same as the UNION ALL operator.
正解：A

質問 2：
Which is NOT a characteristic of dynamic SQL in a program?
A. It uses the EXECUTE statement to execute the prepared statement.
B. It executes a PREPARE statement, which asks the database server to examine the statement text and prepare it for execution.
C. It assembles the text of an SQL statement as a character string.
D. It requires the exact content of every SQL statement to be known at the time the program is written.
正解：D

質問 3：
Which statement about casting is correct?
A. You don't need create casts on distinct types to handle conversions between the new distinct data type and other data types in the database, the server takes care of that automatically.
B. When you create a distinct data type, the database server automatically registers explicit casts from the distinct data type to the source data type and from the source data type to the distinct data type.
C. When you create an opaque data type, the server automatically define template casts to handle conversions between the internal and external representations of the opaque data type.
D. In most cases, you can explicitly cast a named row type to built-in data types without creating the cast.
正解：B

質問 4：
A distinct user defined data type called "dollar" is created as follows:
CREATE DISTINCT TYPE dollar AS DOUBLE PRECISION;
When can you convert it to its base data type double precision?
A. It may always be converted to its base data type.
B. As long as no conversion rate is required.
C. Only when the ALLOW_BASE_CAST attribute is used when creating the type.
D. When a cast function exists between these two types.
正解：D

質問 5：
Which two statements will search text data stored in the column brands of the table products for the string century? (Choose two.)
A. SELECT id FROM products WHERE bts_exists(brands, 'century');
B. SELECT id FROM products WHERE brands MATCHES '*century*';
C. SELECT id FROM products WHERE bts_contains(brands, 'century');
D. SELECT id FROM products WHERE brands LIKE '*century*';
E. SELECT id FROM products WHERE brands = 'century';
正解：B,C

質問 6：
Given the following program code: What is the minimum privilege required to successfully execute the program?

A. CONNECT
B. DBA
C. RESOURCE
D. CREATE
正解：C

質問 7：
You wish to show a user a total balance across all of their savings and checking accounts. However, you do not want them to be blocked or to see inconsistent information if money is being transferred between their accounts at the time of the query. What isolation level would you use?
A. REPEATABLE READ
B. COMMITTED READ LAST COMMITTED
C. READ COMMITTED
D. CURSOR STABILITY LAST COMMITTED
正解：B