nerdexam
Oracle

1Z0-062 · Question #13

Examine the current value for the following parameters in your database instance: SGA_MAX_SIZE = 1024M SGA_TARGET = 700M DB_8K_CACHE_SIZE = 124M LOG_BUFFER = 200M You issue the following command to…

The correct answer is B. It succeeds only if memory is available from the autotuned components if SGA. When ASMM is active via SGA_TARGET, manually sized non-default block size caches like DB_8K_CACHE_SIZE can be increased dynamically, provided autotuned components can yield the required memory.

Managing the Database Instance

Question

Examine the current value for the following parameters in your database instance:

SGA_MAX_SIZE = 1024M SGA_TARGET = 700M DB_8K_CACHE_SIZE = 124M LOG_BUFFER = 200M You issue the following command to increase the value of DB_8K_CACHE_SIZE:

SQL> ALTER SYSTEM SET DB_8K_CACHE_SIZE=140M; Which statement is true?

Options

  • AIt fails because the DB_8K_CACHE_SIZE parameter cannot be changed dynamically.
  • BIt succeeds only if memory is available from the autotuned components if SGA.
  • CIt fails because an increase in DB_8K_CACHE_SIZE cannot be accommodated within
  • DIt fails because an increase in DB_8K_CACHE_SIZE cannot be accommodated within

How the community answered

(18 responses)
  • A
    6% (1)
  • B
    61% (11)
  • C
    22% (4)
  • D
    11% (2)

Why each option

When ASMM is active via SGA_TARGET, manually sized non-default block size caches like DB_8K_CACHE_SIZE can be increased dynamically, provided autotuned components can yield the required memory.

AIt fails because the DB_8K_CACHE_SIZE parameter cannot be changed dynamically.

DB_8K_CACHE_SIZE is a dynamic parameter and can be modified with ALTER SYSTEM without restarting the instance.

BIt succeeds only if memory is available from the autotuned components if SGA.Correct

With SGA_TARGET set, Oracle uses Automatic Shared Memory Management (ASMM) to distribute memory among autotuned components such as the default buffer cache and shared pool. Increasing DB_8K_CACHE_SIZE from 124M to 140M requires only 16M more, which Oracle can reclaim from those autotuned components since total manually pinned memory (140M + 200M = 340M) remains well below the 700M SGA_TARGET boundary. The command therefore succeeds as long as autotuned components have at least 16M available to release.

CIt fails because an increase in DB_8K_CACHE_SIZE cannot be accommodated within

The new total of manually sized components (140M + 200M = 340M) is still far below SGA_TARGET (700M), so there is ample room within SGA_TARGET for the increase.

DIt fails because an increase in DB_8K_CACHE_SIZE cannot be accommodated within

The combined manually sized memory after the change (340M) is also well below SGA_MAX_SIZE (1024M), so the upper SGA boundary does not block the increase.

Concept tested: Oracle ASMM dynamic resizing of non-default block size cache

Source: https://docs.oracle.com/en/database/oracle/oracle-database/19/admin/managing-memory.html

Topics

#SGA#ASMM#DB_CACHE_SIZE#Memory management

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full 1Z0-062 Practice