22.5 About Database Parameters that Impact Performance
Evaluate whether or not database parameters are impacting performance.
There are certain database parameters that can impact performance. In particular,
you should review the memory related parameters (MEMORY_TARGET
,
SGA_TARGET
, PGA_AGGREGATE_TARGET
,
SHARED_POOL_SIZE
) parameters to ensure they are sized correctly.
You should also check that the database System Global Area (SGA) fits in real memory. An
undersized SGA can dramatically impact Application Express performance. There needs to
be sufficient memory in the Shared Pool for PL/SQL and in Buffer Cache for the
Application Express metadata. If the SGA is sized correctly it should not be necessary
to pin PL/SQL programs from the Application Express engine as they are accessed
regularly and should not be swapped out of memory. Because the Application Express
engine resides in the database, it is strongly recommended that you gather statistics on
the APEX_210100
schema. Accurate statistics allow the cost-based
optimizer to develop better query plans for accessing the application metadata.
Parent topic: Managing Application Performance