OCP-1Z0-053-200题-63题-640

QUESTION 63

Examine the parameter setting in your database:

SQL> SHOW PARAMETER TARGET

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

archive_lag_target integer 0

db_flashback_retention_target integer 1440

fast_start_io_target integer 0

fast_start_mttr_target integer 0

memory_max_target big integer 808M

memory_target big integer 808M

pga_aggregate_target big integer 0

sga_target big integer 0

SQL> SHOW PARAMETE SGA_MAX_SIZE

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

sga_max_size big integer 808M

Which statement is correct about the database?

A. Automatic memory management is disabled because PGA_AGGREGATE_TARGET and SGA_TARGET

are not set

B. The instance is started but the database will not be opened until PGA_AGGREGATE_TARGET and

SGA_TARGET are set

C. The database is opened but users cannot perform transactions until PGA_AGGREGATE_TARGET and

SGA_TARGET are set

D. Automatic memory management is enabled and, as perpolicy, 60% of the memory for System Global Area

(SGA) and 40% of the memory for Program Global Area (PGA)will be distributed at startup

Answer: D

同640题：/article/1348454.html

Explanation/Reference:

Section: Managing Database Performance & Tuning

Not sure about the policy stuff, but it's the default behavior when memory_target and memory_max_target are

set, sga_max_target is always set automatically to the same value as memory_max_target
http://download.oracle.com/docs/cd/B14117_01/server.101/b10752/memory.htm#47750
Configuring Automatic PGA Memory

When configuring a brand new instance, it is hard to know precisely the appropriate setting for

PGA_AGGREGATE_TARGET. You can determine this setting in three stages:

Make a first estimate for PGA_AGGREGATE_TARGET, based on a rule of thumb. By default, Oracle

uses

20% of the SGA size. However, this initial setting may be too low for a large DSS system.

Run a representative workload on the instance and monitor performance, using PGA statistics collected

by Oracle, to see whether the maximum PGA size is under-configured or over-configured.

Tune PGA_AGGREGATE_TARGET, using Oracle PGA advice statistics.