Which three are true about SGA memory management in a multitenant database? (Choose three.)

Question

Options

• ASetting DB_CACHE_SIZE for a PDB guarantees a minimum amount of Database Buffer Cache
• BThe SHARED_POOL_SIZE setting for a PDB can be up to 80%of the SHARED_POOL_SIZE
• CSetting SHARED_POOL_SIZE for a PDB guarantees a minimum amount of Shared Pool memory
• DThe SGA_TARGET setting for a PDB cannot exceed 50%of the SGA_TARGET value of the root
• ESetting SGA_TARGET for a PDB guarantees a minimum amount of SGA memory for that PDB.
• FSGA_MIN_SIZE cannot be set for a PDB.

• A
  47% (29)
• B
  29% (18)
• E
  8% (5)
• F
  16% (10)

Explanation

In Oracle multitenant, setting component-level parameters like DB_CACHE_SIZE and SHARED_POOL_SIZE at the PDB level acts as a floor - they guarantee that PDB a minimum allocation of that specific memory component, making A and C correct. Option D is correct because Oracle enforces a hard limit: a PDB's SGA_TARGET cannot exceed 50% of the CDB root's SGA_TARGET, preventing any single PDB from monopolizing shared SGA.

Why the distractors are wrong:

• B is wrong because the 80% figure is fabricated - no such percentage rule applies to SHARED_POOL_SIZE in a PDB.
• E is wrong because SGA_TARGET in a PDB sets a maximum cap, not a minimum guarantee; use SGA_MIN_SIZE for minimums.
• F is wrong because SGA_MIN_SIZE absolutely can be set for a PDB - it is precisely the parameter used to guarantee a minimum total SGA allocation for a PDB.

Memory tip: Think "SIZE = floor, TARGET = ceiling" - the _SIZE parameters (DB_CACHE_SIZE, SHARED_POOL_SIZE) set minimums, while SGA_TARGET sets a maximum that is itself capped at 50% of the root's value.

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