Which three are true about SGA memory management in a multitenant database? (Choose three.)
Which three are true about SGA memory management in a multitenant database? (Choose three.)
In a multitenant database, setting DB_CACHE_SIZE for a PDB guarantees a minimum amount of Database Buffer Cache memory for that PDB. Similarly, setting SHARED_POOL_SIZE for a PDB guarantees a minimum amount of Shared Pool memory for that PDB. The SGA_TARGET setting for a PDB cannot exceed 50% of the SGA_TARGET value of the root container.
PDB Memory Parameters The following parameters can be set at the PDB level. DB_CACHE_SIZE : The minimum buffer cache size for the PDB. SHARED_POOL_SIZE : The minimum shared pool size for the PDB. PGA_AGGREGATE_LIMIT : The maximum PGA size for the PDB. PGA_AGGREGATE_TARGET : The target PGA size for the PDB. SGA_MIN_SIZE : The minimum SGA size for the PDB. SGA_TARGET : The maximum SGA size for the PDB. A,C: Correct D is correct for SGA_MIN_SIZE, but not for SGA_TARGET
I agree
F is false: SGA_MIN_SIZE - Sets the minimum SGA size for the PDB. D is True: It must be less than or equal to 50% of the setting for the SHARED_POOL_SIZE in the CDB root. Answer is ACD https://docs.oracle.com/en/database/oracle/oracle-database/19/multi/using-oracle-resource-manager-for-pdbs-with-sql-plus.html#GUID-A3459A8B-A36A-44D4-9FCD-75CA0E3D3252
SGA_MIN_SIZE - It must be less than or equal to 50% of the setting for the SGA_TARGET in the PDB.
If Automatic Memory Management is enabled (MEMORY_TARGET is set to a positive value) and SGA_TARGET is also set to a positive value, the SGA_TARGET value acts as the minimum value for the size of the SGA.
bad answers. A&C are def correct per the documentation. E can be technically correct but only under the following condition: If Automatic Memory Management is enabled (MEMORY_TARGET is set to a positive value) and SGA_TARGET is also set to a positive value, the SGA_TARGET value acts as the minimum value for the size of the SGA. from: https://docs.oracle.com/en/database/oracle/oracle-database/21/refrn/SGA_TARGET.html#GUID-4702FDB7-BADC-4997-BC49-1B91088234AE not clear from the answers but E is the only one that sort of fits.
Agreed ACE
B is incorrect, only two answers are correct
ACD is answer
ACE https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/SGA_TARGET.html#GUID-4702FDB7-BADC-4997-BC49-1B91088234AE >>SGA_TARGET value acts as the minimum value for the size of the SGA.
E is wrong. From the article you linked: "When this parameter is set for a PDB, it specifies the maximum SGA that the PDB can use at any time." not minimum, but maximum
ACD Doc ID 2170772.1
or more granular control, you can even set the parameters like DB_CACHE_SIZE (guaranteed Buffer Cache size for PDB) and SHARED_POOL_SIZE (guaranteed Shared Pool size for PDB) too.
alter system set shared_pool_size=1500M; alter system set shared_pool_size=1500M * ERROR at line 1: ORA-02097: parameter cannot be modified because specified value is invalid ORA-56748: invalid value 1572864000 for parameter shared_pool_size; must be smaller than 50% of parameter sga_target of the root container
answer :A and C
SGA_TARGET Sets the maximum SGA size for the PDB. The SGA_TARGET setting in the PDB is enforced only if the SGA_TARGET initialization parameter is set to a nonzero value in the CDB root. The SGA_TARGET setting in the PDB must be less than or equal to the SGA_TARGET setting in the CDB root.
SGA_MIN_SIZE Sets the minimum SGA size for the PDB. The following requirements must be met: It must be less than or equal to 50% of the setting for the SGA_TARGET in the CDB root. It must be less than or equal to 50% of the setting for the SGA_TARGET in the PDB. The sum of the SGA_MIN_SIZE settings for all PDBs must be less than or equal to 50% of the setting for the SGA_TARGET in the CDB root. These requirements do not apply if the SGA_TARGET initialization parameter is not set or is set to 0 (zero) in the CDB root.
SHARED_POOL_SIZE Sets the minimum, guaranteed shared pool space for the PDB. The following requirements must be met: It must be less than or equal to 50% of the setting for the SHARED_POOL_SIZE in the CDB root. The sum of the SHARED_POOL_SIZE settings for all PDBs must be less than or equal to 50% of the setting for the SHARED_POOL_SIZE in the CDB root. These requirements do not apply if the SGA_TARGET initialization parameter is set to a nonzero value in the CDB root. When the SGA_TARGET initialization parameter is set to a nonzero, the following requirements must be met: The values of DB_CACHE_SIZE plus SHARED_POOL_SIZE in a PDB must be less than or equal to 50% of the PDB’s SGA_TARGET value. The values of DB_CACHE_SIZE plus SHARED_POOL_SIZE in a PDB must be less than or equal to 50% of the SGA_TARGET value at the CDB level. The sum of DB_CACHE_SIZE plus SHARED_POOL_SIZE across all the PDBs in a CDB must be less than or equal to 50% of the SGA_TARGET value at the CDB level.
DB_CACHE_SIZE Sets the minimum, guaranteed buffer cache space for the PDB. The following requirements must be met: It must be less than or equal to 50% of the setting for the DB_CACHE_SIZE in the CDB root. The sum of the DB_CACHE_SIZE settings for all PDBs must be less than or equal to 50% of the setting for the DB_CACHE_SIZE in the CDB root. These requirements do not apply if the SGA_TARGET initialization parameter is set to a nonzero value in the CDB root. When the SGA_TARGET initialization parameter is set to a nonzero, the following requirements must be met: The values of DB_CACHE_SIZE plus SHARED_POOL_SIZE in a PDB must be less than or equal to 50% of the PDB’s SGA_TARGET value. The values of DB_CACHE_SIZE plus SHARED_POOL_SIZE in a PDB must be less than or equal to 50% of the SGA_TARGET value at the CDB level. The sum of DB_CACHE_SIZE plus SHARED_POOL_SIZE across all the PDBs in a CDB must be less than or equal to 50% of the SGA_TARGET value at the CDB level.
Which three are true about SGA memory management in a multitenant database? (Choose three.) A. Setting DB_CACHE_SIZE for a PDB guarantees a minimum amount of Database Buffer Cache memory for that PDB. B. The SHARED_POOL_SIZE setting for a PDB can be up to 80% of the SHARED_POOL_SIZE setting of the root container. C. Setting SHARED_POOL_SIZE for a PDB guarantees a minimum amount of Shared Pool memory for that PDB. D. The SGA_TARGET setting for a PDB cannot exceed 50% of the SGA_TARGET value of the root container. E. Setting SGA_TARGET for a PDB guarantees a minimum amount of SGA memory for that PDB. F. SGA_MIN_SIZE cannot be set for a PDB.
It is ABC https://docs.oracle.com/en/database/oracle/oracle-database/19/multi/using-oracle-resource-manager-for-pdbs-with-sql-plus.html#GUID-A3459A8B-A36A-44D4-9FCD-75CA0E3D3252
A,C correct B, incorrect, 50% or less E, incorrect:When this parameter is set for a PDB, it specifies the maximum SGA that the PDB can use at any time. F: incorrect: 50% or less
ACE https://docs.oracle.com/en/database/oracle/oracle-database/19/multi/using-oracle-resource-manager-for-pdbs-with-sql-plus.html#GUID-A3459A8B-A36A-44D4-9FCD-75CA0E3D3252