Advisory for estimate the value of MEMORY_TARGET, SGA and PGA parameter

Memory Target Advisory: Enhance Oracle Database Performance

Memory Target Advisory: This feature, introduced in Oracle 11g, helps manage memory tuning. The MEMORY_TARGET parameter combines SGA and PGA. You don’t need to separately define the SGA_TARGET and PGA_TARGET parameters in the initialization parameter file.
Note: If you set SGA_TARGET or PGA_TARGET to a value other than 0, it will be treated as the minimum SGA or PGA value during instance startup, while the MEMORY_TARGET parameter controls the maximum.

Memory Target = SGA + PGA

select memory_size,memory_size_factor,estd_db_time from v$memory_target_advice;

Check the SGA Target size with SGA Advisory in Oracle

SGA Advisor: It provides data on SGA tuning, including current memory space utilization and the effects of increasing it. The sga_target parameter in the Parameter file sets the SGA size. SGA_target automatically allocates values to db_cache, large_pool, shared_pool, and java_pool.

SGA Target = SHARED_POOL + DB_CACHE + LARGE POOL + JAVA POOL

select sga_size, sga_size_factor, estd_db_time from v$sga_target_advice;

Check the PGA Target size with PGA Advisory in Oracle

PGA Advisor: This is the memory required by a session to carry out its tasks, defined by the PGA_TARGET parameter in Oracle.

select pga_target_for_estimate,pga_target_factor,estd_extra_bytes_rw from v$pga_target_advice;