State Object
A data structure used to record the state of resources
held by an operating system process.State objects are
used to facilitate recovery from a process failure within
an Oracle instance.
A state object consists of a generic portion, and a
object type unique portion.Specific state object types
include the following:
Process state object
Session state object
Transaction state object
Buffer state object
Call state object
State objects are linked to form a tree structure,
with a process state object being at the root of the
tree.On process failure, the PMON background process
recovers and frees the resources associated with the
failed process by walking the tree structure of state
objects rooted by the process state object corresponding
to the failed process.
State objects are necessarily contained in the SGA to
allow access by the PMON/SMON background processes.
