Databases Reference
In-Depth Information
temporal extent state transformation
Mechanics:
a transformation to an asserted version table in which, within a given
period of assertion time, the number of effective-time clock ticks which a
given episode occupies is increased or decreased.
Semantics:
a transformation altering the temporal extent of an episode's effective
time period, within a given period of assertion time.
Comments:
In the definitions of the temporal extent state transformations, the
phrase “in a given period of assertion time” will be present
implicitly.
Components:
asserted version table, assertion time, clock tick, effective time,
episode, occupied.
temporal extent state transformation taxonomy
Description:
a taxonomy of additions to or deletions from the set of clock ticks
which contain a representation of an object in an asserted version table,
developed by the authors and presented in Chapter 9.
temporal extent state transformation taxonomy, {create}
Mechanics:
the temporal extent state transformation that adds the representation
of an object to an effective time period that is either [before] or [before
1
] the
effective time period of any episode of that object already present in
the table.
Semantics:
the temporal extent state transformation that adds a new episode to
an asserted version table.
Components:
asserted version table, effective time, episode, object, represent.
temporal extent state transformation taxonomy, {delete}
Mechanics:
the temporal extent state transformation that, in a given period of
assertion time, removes the representation of an object from an effective time
period that is either [before] or [before
1
] all other representations of that
same object.
Semantics:
the temporal extent state transformation that removes an entire
episode from current assertion time.
Components:
Allen relationship taxonomy [before], Allen relationship taxonomy
[before
1
], assertion time, effective time, object, represent.
temporal extent state transformation taxonomy, {lengthen backwards}
Mechanics:
the temporal extent state transformation that adds the representation
of an object to an effective time period that [meets] the effective time period
of an episode of that object already present in the table.
Semantics:
the temporal extent state transformation that expands the effective
time period of an episode into a contiguous, earlier time period.
Components:
Allen relationship [meets], effective time period, episode, object,
representation.
temporal extent state transformation taxonomy, {lengthen forwards}
Mechanics:
the temporal extent state transformation that adds the
representation of an object to an effective time period that [meets
1
]
the effective time period of an episode of that object already present in the
table.
Semantics:
the temporal extent state transformation that expands the effective
time period of an episode into a contiguous, later time period.
