V$IM_COLUMN_LEVEL

V$IM_COLUMN_LEVEL presents the selective column compression levels that are defined using the inmemory_memcompress clause of the inmemory_column_clause of the CREATE TABLE statement.

This view returns no rows for a table which has no associated selective column compression levels.

Column Datatype Description
INST_ID NUMBER Instance ID
OWNER VARCHAR2(31) Username of the table owner
OBJ_NUM NUMBER Table object number
TABLE_NAME VARCHAR2(31) Table name
SEGMENT_COLUMN_ID NUMBER Segment column number
COLUMN_NAME VARCHAR2(31) Column name
INMEMORY_COMPRESSION VARCHAR2(26)

Column compression level. Possible values:

  • DEFAULT: This value appears for physical columns of a table that do not have a selective column clause. It also appears when a virtual column has been explicitly enabled for in-memory storage using ALTER TABLE table-name INMEMORY(VC).

  • UNSPECIFIED: This value appears for virtual columns of a table that do not have a selective column clause.

If the INMEMORY_VIRTUAL_COLUMNS initialization parameter is set to MANUAL, a virtual column with a DEFAULT INMEMORY_COMPRESSION clause will be materialized while a virtual column with an UNSPECIFIED value will not be.

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

Note: The SYS_IME hidden virtual columns automatically added by the In-Memory Expression (IME) infrastructure will not be shown in this view.

See Also: