DBA_HIST_MEMORY_TARGET_ADVICE displays memory target advice history.
This view contains snapshots of V$MEMORY_TARGET_ADVICE.
Unique snapshot ID
Database ID for the snapshot
Instance number for the snapshot
If the MEMORY_SIZE_FACTOR column has a value of 1, then this column shows the current size of memory, as set by the MEMORY_TARGET initialization parameter.
If the value of the MEMORY_SIZE_FACTOR column is less than or greater than 1, then this column shows a proposed memory size.
A multiplier for the current memory size. Possible values are 0.25, 0.5, 0.75, 1, 1.5, 1.75 and 2. This multiplier times the current memory size equals the value of the MEMORY_SIZE column.
For current memory size (MEMORY_SIZE_FACTOR = 1), the amount of database time required to complete the current workload. For a proposed memory size, the estimated amount of database time that would be required if the MEMORY_TARGET parameter were changed to the proposed size.
For a proposed memory size, ratio of estimated database time to current database time
Version number of this recommendation
The database ID of the PDB for the sampled session
The ID of the container that CON_DBID identifies. Possible values include:
0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.
1: This value is used for rows containing data that pertain to only the root
n: Where n is the applicable container ID for the rows containing data