8.6 V$INMEMORY_AREA

V$INMEMORY_AREA contains information on the space allocation inside the In-Memory area.

The In-Memory area is sub-divided into two pools: a 1MB pool used to store the actual column formatted data populated into memory, and a 64K pool used to store metadata about the objects that are populated into the In-Memory Column Store (IM column store). The amount of available memory in each pool is visible in the V$INMEMORY_AREA view. The relative size of the two pools is determined by internal heuristics. The majority of the In-Memory area memory is allocated to the 1MB pool.

Column Datatype Description

POOL

VARCHAR2(26)

Name of the pools in the In-Memory area

ALLOC_BYTES

NUMBER

Total amount of memory allocated to this pool

USED_BYTES

NUMBER

Amount of memory currently used in this pool

POPULATE_STATUS

VARCHAR2(26)

Shows the status of the IM column store, for example, whether it is currently being populated or if it is done

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire multitenant container database (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