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Sizing the PGA in Oracle 19c - How to Account for the MGA Size (Doc ID 2808761.1)

Last updated on APRIL 17, 2023

Applies to:

Oracle Database - Enterprise Edition - Version and later
Oracle Database - Standard Edition - Version and later
Information in this document applies to any platform.


In Oracle 18c and up, the space allocated to the MGA (Managed Global Area) is included in total amount of memory allocated to the PGA. This can be see from v$pgastat:

Therefore it follows that when upgrading from an earlier version, the maximum allowable PGA size (PGA_AGGREGATE_LIMIT) must be increased to account for the MGA. See the following note for a detailed description of the MGA and its functions:

MGA (Managed Global Area) Reference Note (<Document 2638904.1>)

But how much should PGA_AGGREGATE_LIMIT be increased to account for the MGA?


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