3. You execute the following SQL statement: LOCK TABLE orders IN SHARE MODE; Wha
ID: 3594697 • Letter: 3
Question
3. You execute the following SQL statement:
LOCK TABLE orders IN SHARE MODE;
What effect does this have on the table? *This question is required.
a. You can SELECT from the table, but no one else can
b. You can SELECT from the table, and so can other users
c. You can SELECT, INSERT, UPDATE, or DELETE from the table, but no one else can
d. You can SELECT from the table, and other users can SELECT, INSERT, UPDATE, and DELETE from the table
4. Which of the following statements are TRUE concerning referential constraints? (Choose all that apply) *This question is required.
a. The parent column (or set of columns) must have a primary key constraint
b. The child column (or set of columns) must have a primary key constraint
c. The parent column (or set of columns) must have either a primary key or unique constraint
d. The child column (or set of columns) must have either a primary key or unique constraint
5. How often does a BTSCANNER thread run to delete key values from an index? (Choose all that apply) *This question is required.
a. Once for every row in a corresponding table that is deleted
b. Once per minute
c. Whenever the number of requests in the B-tree scanner pool exceeds 100
d. Never, because the key values are deleted by a BTCLEANER thread
6. Consider the following statement:
This option uses a less sophisticated, but faster algorithm which eliminates more of the join options earlier in the optimization phase, reducing time spent analyzing possible paths.
Which of the following does this statement describe? *This question is required.
a. SET OPTIMIZATION LOW
b. SET OPTIMIZATION HIGH
c. SET OPTIMIZATION FIRST_ROWS
d. SET OPTIMIZATION ALL_ROWS
Explanation / Answer
3. c. You can SELECT, INSERT, UPDATE, or DELETE from the table, but no one else can
4.
a. The parent column (or set of columns) must have a primary key constraint
d. The child column (or set of columns) must have either a primary key or unique constraint
5.
a. Once for every row in a corresponding table that is deleted
c. Whenever the number of requests in the B-tree scanner pool exceeds 100
6. a. SET OPTIMIZATION LOW
**Comment for any further queries.
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