DBA_HIST_PARAMETER displays historical information about the initialization parameters that were in effect for the instance. This view contains snapshots of V$SYSTEM_PARAMETER.

Column Datatype NULL Description
SNAP_ID NUMBER   Unique snapshot ID
DBID NUMBER   Database ID for the snapshot
INSTANCE_NUMBER NUMBER   Instance number for the snapshot
PARAMETER_NAME VARCHAR2(64)   Name of the parameter
VALUE VARCHAR2(512)   Parameter value for the session (if modified within the session); otherwise, the instance-wide parameter value
ISDEFAULT VARCHAR2(9)   Indicates whether the parameter is set to the default value (TRUE) or the parameter value was specified in the parameter file (FALSE)
ISMODIFIED VARCHAR2(10)   Indicates whether the parameter has been modified after instance startup:
  • MODIFIED - Parameter has been modified with ALTER SESSION

  • SYSTEM_MOD - Parameter has been modified with ALTER SYSTEM (which causes all the currently logged in sessions' values to be modified)

  • FALSE - Parameter has not been modified after instance startup