Incompatibilidad entre AMM y HughPages

The 11g AMM feature is enabled by the MEMORY_TARGET / MEMORY_MAX_TARGET instance initialization parameters . That is also the case with a default database instance created using Database Configuration Assistant (DBCA).

With AMM all SGA memory is allocated by creating files under /dev/shm. When Oracle DB does SGA allocations that way HugePages are not reserved/used.

The use of AMM is absolutely incompatible with HugePages. (Please see references at the end of the document for further information on HugePages)

On systems with HugePages in use, attempting to set the MEMORY_TARGET / MEMORY_MAX_TARGET instance initialization parameters may result in the following error message:

ORA-00845: MEMORY_TARGET not supported on this system