Databases Reference
In-Depth Information
basic versioning
Mechanics:
a form of versioning in which a version date is added to the primary
key of an otherwise non-temporal table.
Semantics:
a form of versioning in which all versions of the same object are
contiguous.
Comments:
Basic versioning is not part of Asserted Versioning. It is a form of best
practices versioning. See Chapter 4.
See also:
logical delete versioning, temporal gap versioning, effective time
versioning
.
Components:
contiguous, object, non-temporal table, version.
begin date
Mechanics:
an assertion begin date or an effective begin date.
Semantics:
a date which marks the start of an assertion or an effective time
period.
Components:
assertion begin date, assertion time period, effective begin date,
effective time period.
bi-temporal data canonical form
Mechanics:
the schema common to all asserted version tables.
Semantics:
a single schema which can express the full range of bi-temporal
semantics.
Comments:
Any history table, logfile, or version table can be transformed into an
asserted version table without loss of content.
Components:
asserted version table, bi-temporal.
bi-temporal database
Mechanics:
a database containing at least one bi-temporal table.
Components:
bi-temporal table.
bi-temporal envelope
Semantics:
a specified effective time period, included within a specified assertion
time period.
Comments:
The temporal scope of every temporal transaction is delimited by the
bi-temporal envelope specified on the transaction.
Every row in an asserted version table exists in a bi-temporal
envelope.
Components:
assertion time period, effective time period, include.
bi-temporal table
Mechanics:
a table whose rows contain one pair of dates which define an
epistemological time period, and a second pair of dates which define an
ontological time period.
Semantics:
a table whose rows contain data about both the past, the present and
the future of things, and also about the past and the present of our beliefs
about those things.
Comments
.
See also:
epistemological time, ontological time
.
Components:
“assert” cognate (belief ), epistemological time, ontological time,
thing, time period.
