Subject: March issue of SIGMOD Record: Temporal Database Infrastructure

From: "Rick Snodgrass" <rts>
Date: Tue, 1 Mar 1994 16:47:28 MST

Sometime this month the March issue of ACM SIGMOD Record will appear.
This issue will contain a special section giving the results of the
workshop and follow-on efforts. Specifically, it will include the following
reports.

Snodgrass, R.T. (editor), ``Temporal Database Infrastructure,'' Special Section
of {\it SIGMOD Record}, Vol.~23, No.~1, March, 1994, page 34.\\

Pissinou, N., R.T.~Snodgrass, R.~Elmasri, I.S.~Mumick, M.T.~\"{O}zsu,
B.~Pernici, A.~Segev, and B.~Theodoulidis, ``Towards an Infrastructure
for Temporal Databases: Report of an Invitational ARPA/NSF Workshop,''
{\it SIGMOD Record}, Vol.~23, No.~1, March, 1994, pp.~35--51. Also
Technical Report TR 94-01, Department of Computer Science, University
of Arizona, March, 1994, 54 pages.\\

Jensen, C.S., J.~Clifford, R.~Elmasri, S.K.~Gadia, P.~Hayes,
S.~Jajodia (eds), C.E.~Dyreson, F.~Grandi, W.~K\"{a}fer, N.~Kline,
N.~Lorentzos, Y.~Mitsopoulos, A.~Montanari, D.~Nonen, E.~Peressi,
B.~Pernici, J.F.~Roddick, N.L.~Sarda, M.R.~Scalas, A.~Segev,
R.T.~Snodgrass, M.D.~Soo, A.~Tansel, R.~Tiberio and G.~Wiederhold, ``A
Consensus Glossary of Temporal Database Concepts,'' {\it SIGMOD
Record}, Vol.~23, No.~1, March, 1994, pp.~52--64.  Also Technical Report
R 93-2035, Dept. of Mathematics and Computer Science, Aalborg
University, Denmark, November, 1993, 55 pages.\\

Snodgrass, R.T., I.~Ahn, G.~Ariav, D.S.~Batory, J.~Clifford, C.E.~Dyreson,
R.~Elmasri, F.~Grandi, C.S.~Jensen, W.~K\"{a}fer, N.~Kline, K.~Kulkanri,
T.Y.C.~Leung, N.~Lorentzos, J.F.~Roddick, A.~Segev,
M.D.~Soo, and S.M.~Sripada, ``TSQL2 Language Specification,''
{\it SIGMOD Record}, Vol.~23, No.~1, March, 1994, pp.~65--86.\\

Other reports will soon be available (within the next few days). The
following is the introduction to the special section, providing
information on availability.

		   Overview of the Special Section
		 on Temporal Database Infrastructure

			 Richard T. Snodgrass
		    Department of Computer Science
			University of Arizona
			   Tucson, AZ 85721

			  [email-masked]

The area of temporal databases has been active for the last fifteen
years, with a corpus nearing 800 papers. Most applications need to
store time-varying data, yet there are no widely used commercial
temporal databases. A primary reason for the absence of technology
transfer from research to practice is the lack of a commonly accepted
consensus data model or query language.  Even the terminology is
inconsistent.

On June 14-16, 1993, the ARPA/NSF International Workshop on an
Infrastructure for Temporal Databases was held in Arlington, Texas.
Forty-four prominent researchers from ten countries, representing ten
industrial labs and companies and over twenty universities,
participated in this workshop.

This special section presents some of the results of that workshop and
associated activities.  The first paper is an abbreviated version
of the workshop report. The conclusions of the four working groups
that met during the workshop are documented there.

The second paper provides a condensed version of a glossary of
temporal database concepts, ironed out through a long dialogue, first
via electronic mail over nine months, then at the workshop, and then
back to email, again over several months.

The third report provides the initial specification for a consensus
temporal extension to SQL-92, termed TSQL2. This is the first
definition of a temporal query language to draw on the expertise of a
substantial portion of the temporal database community.

All of these reports are also available on-line, in the tsql directory
at FTP.cs.arizona.edu. More complete versions are also available there
via anonymous FTP. In particular, there is the complete version of the
workshop report (at 54 pages), the extended version of the glossary,
with more discussion of the terms (at 55 pages), a separate consensus
temporal query language test suite (at 45 pages), and twenty-three
commentaries discussing the major design decisions of the TSQL2
language (totaling 350 pages). Hard copies are available upon request
to Robyn Austin, Department of Computer Science, University of
Arizona, Tucson, AZ 85721, [email-masked]. The commentaries, in
a binder, cost $60; the other documents are free while supplies last.
The proceedings of the workshop (43 position papers totaling 624
pages) is also available, at $35.  Both large documents are sent via
airmail in the U.S. and via ground book rate elsewhere (which can take
several months). Foreign air mail book rate is available for an
additional $20.

In sum, the last two years have seen a blossoming of consensual
efforts within the temporal database community. The workshop and its
report, the glossary, the temporal query language test suite and the
TSQL2 language definition are tangible artifacts of the community's
willingness to work together to produce a realistic, coherent,
articulated infrastructure on which future research and industrial
development can proceed.

I wish to extend a sincere thanks to the large number of dedicated
individuals who participated in one or more of these efforts. Of
these, several were particularly helpful. Gio Wiederhold has pushed
for an infrastructure for temporal databases for many years.  Maria
Zemankova was instrumental in shepherding the initial workshop
proposal through an NSF review. Without their diligence the workshop
would never have occurred. Niki Pissinou served ably as general chair
for the workshop. The members of the workshop steering committee
actively organized the meeting, then captured the discussions as
authors of the workshop report.  Christian S. Jensen so capably lead
the glossary and test suite efforts. It has been thoroughly enjoyable
working with such talented people.