Upgrade to Oracle Database 12c: 1Z0-060

Correct Answer: ACE

* In bind variable peeking (also known as bind peeking), the optimizer looks at the value in a bind variable when the database performs a hard parse of a statement.

When a query uses literals, the optimizer can use the literal values to find the best plan. However, when a query uses bind variables, the optimizer must select the best plan without the presence of literals in the SQL text. This task can be extremely difficult. By peeking at bind values the optimizer can determine the selectivity of a WHERE clause condition as if literals had been used, thereby improving the plan.

C: Oracle 11g/12g uses Adaptive Cursor Sharing to solve this problem by allowing the server to compare the effectiveness of execution plans between executions with different bind variable values. If it notices suboptimal plans, it allows certain bind variable values, or ranges of values, to use alternate execution plans for the same statement. This functionality requires no additional configuration.

Correct Answer: AC

A: Variable size extents enable support for larger ASM datafiles, reduce SGA memory requirements for very large databases (A), and improve performance for file create and open operations.

C: You don't have to worry about the sizes; the ASM instance automatically allocates the appropriate extent size.

Note:

*

The contents of ASM files are stored in a disk group as a set, or collection, of data extents that are stored

on individual disks within disk groups. Each extent resides on an individual disk. Extents consist of one or

more allocation units (AU).

To accommodate increasingly larger files, ASM uses variable size extents.

*

The size of the extent map that defines a file can be smaller by a factor of 8 and 64 depending on the file

size. The initial extent size is equal to the allocation unit size and it increases by a factor of 8 and 64 at

predefined thresholds. This feature is automatic for newly created and resized datafiles when the disk

group compatibility attributes are set to Oracle Release 11 or higher.

Correct Answer: AD