Tài liệu Managing time in relational databases- P22 doc
Tài liệu Managing time in relational databases- P22 doc
... relationships between two time periods, a time
period and a point in time, or two points in time, as first defined in James F.
Allen’s 1983 article Maintaining Knowledge about Temporal Intervals.
Semantics: ... transition from one point in effective time or assertion time to the
next point in effective time or assertion time, according to the chosen
granularity which de...
Tài liệu Managing time in relational databases- P3 doc
... point
in time forward to the point in time we are interested in.
But the defining feature of reconstructable methods is not the
movement of data from off-line to on-line storage. The defining ... waiting for the data, and the decisions
delayed until the data becomes available. In an increasingly
fast-paced business world, the opportunity cost of delays in
accessing data is incre...
Tài liệu Managing time in relational databases- P10 docx
... bigint
eff_beg_dt: datetime
asr_beg_dt: datetime
wellpgmcat_oid: bigint
eff_beg_dt: datetime
eff_end_dt: datetime
asr_end_dt: datetime
row_crt_dt: datetime
client_wellpgm_oid: bigint
eff_beg_dt: datetime
asr_beg_dt: ... tables in those databases into bi-temporal asserted
Managing Time in Relational Databases. Doi: 10.1016/B978-0-12-375041-9.00008-X
Copyright
#
2010 Elsevier Inc. Al...
Tài liệu Managing time in relational databases- P11 doc
... taxonomy in terms of its topology. On a line representing a
timeline, we can place a line segment representing an episode.
We can also remove a line segment from that line. Given a line
segment, ... significantly reduces the work involved in maintaining
temporal data, and will eliminate the errors that would otherwise
inevitably happen as temporal data is maintained.
Using a framework lik...
Tài liệu Managing time in relational databases- P17 doc
... dates.
Time Period to Time Period Queries
Allen relationships may relate two time periods, or a time
period to a point in time, or two points in time. We will represent
time periods, using our ... currently claim were in effect any time in
the first half of 2008.
Pinning down a point in assertion time, and then asking for
versions of objects claimed at that point in...
Tài liệu Managing time in relational databases- P18 doc
... OTHER QUERIES
Point in Time to Period of Time Queries
A point in time is a period of time that includes only one
clock tick. Thus, using the closed-open convention, a point in
time, T
1
, is identical ... relationships, and taxonomic groupings of
them, between pairs of time periods, between a time period
and a point in time, and between two points in time. Once again,...
Tài liệu Managing time in relational databases- P20 doc
... the
lower cardinality columns. Clustering would continue based on
3
Low cardinality means that there are fewer distinct values for the field in the table
which results in more rows having a single value.
Chapter ... querying. There is no delay between the
business request for data, and its availability in queryable form.
The majority of queries against bi-temporal data are point -in-
t...
Tài liệu Managing time in relational databases- P21 doc
... d by their starting point in time and
ending point in time. These points in time may be timestamps,
dates, or any other point in time recognizable by the DBMS.
As defined in this Glossary, they ... origin of data ware-
housing in just as incontrovertible a sense as Dr. E. F. Codd’s early
articles were the origins of relational theory.
1996: Building the Data Warehouse
Wil...
Tài liệu Managing time in relational databases- P1 ppt
... data in which none of that is
necessary, a world in which all pipeline datasets are contained
in the single table that is their destination or their point of origin.
In this world, maintaining ... useful by integrating them into
larger patterns. But he has worked in the world of business IT for
his entire career. And in that world, theory is fine, but it must
xx
PREFACE
MANAGING...
Tài liệu Managing time in relational databases- P2 pptx
... Versioning
Asserted Versioning Framework (AVF)
xxii
PREFACE
row the query author is interested in, two of those components
being time periods that may or may not intersect in various
ways. Continuing ... management losing
faith in data warehouse projects. As these large projects fell
increasingly behind schedule and rose increasingly over budget—
something large projects tend to do—the...