Databases Reference
In-Depth Information
12
DEFERRED ASSERTIONS AND
OTHER PIPELINE DATASETS
CONTENTS
The Semantics of Deferred Assertion Time
Assertions, Statements and Time
264
The Internalization of Pipeline Datasets
Deferred Assertions
269
A Deferred Update to a Current Episode
269
A Deferred Update to a Deferred Assertion
Reflections on Empty Assertion Time
275
Completing the Deferred Update to a Deferred Assertion
The Near Future and the Far Future
279
Approving a Deferred Assertion
280
Deferred Assertions and Temporal Referential Integrity
Glossary References
We normally think of inserting a row into a table as the same
thing as claiming, or asserting, that the statement which that row
makes is true. From that point of view, a distinction between the
physical act of creating a row in a table, and the semantic act of
claiming that what the row says is true, is a distinction without a
difference.
This is why, we surmise, the computer science community
calls the second of their two bi-temporal dimensions “trans-
action time”, an expression with obvious physical connotations.
Yet while a transaction is a physical act, an assertion is not. It
is a semantic act. And while the semantic act can't happen
before the physical one, we see no reason why it can't happen
after it, and a number of advantages that result if it can.
With the standard temporal model, the rows inserted into
bi-temporal tables begin to be asserted on the date they are
physically inserted into the database. With Asserted Versioning,
this is the default for those rows; but Asserted Versioning permits
