From rts Mon Jun 28 21:05:04 1993
Date: Mon, 28 Jun 1993 21:04:35 MST
From: "Rick Snodgrass" <rts>
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Subject: follow-on language design efforts
Status: RO
Content-Length: 2387
X-Lines: 53

One major objective of the temporal database infrastructure workshop
was to initiate the design of a consensus temporal extension of SQL.
There were three conflicting viewpoints on such an extension voiced by
the workshop participants (with associated rationales, not repeated
here):

(a) With the addition of an interval data type, there will be
sufficient support in SQL2/3 to support applications using temporal
data.  Further temporal support should not be added.

(b) SQL2, and the proposed SQL3, require temporal support to be added
to the language. A two-pronged effort should be initiated, the first
being a short-term effort to define a temporal extension to SQL2 and
the second being a long-term effort to define a comprehensive
extension to SQL3.

(c) Temporal support should be added to the query language, but only
SQL3 should be extended.

These three viewpoints are clearly at variance. So, instead of a
single consensual effort, which appears to be unattainable, I propose
three separate efforts, each reflecting the approach espoused by a
significant portion of the TDB community, and together enabling
further progress.

* SQL2/3
	Those agreeing with viewpoint (a) form a working group to
define an interval data type and write SQL2 (or SQL3) queries for the
benchmark queries, so that this approach can be compared with other
proposals.

* TSQL2
	Those agreeing with viewpoint (b) form a working group to
define a short-term temporal extension to SQL2.

* TSQL3
	Those agreeing with viewpoint (b) or with viewpoint (c) form a
working group to define a long-term temporal extension to SQL3.

The initial reports of these working groups could be made part of the
final report of the workshop, if they were completed by August 23.
However, the activities of these working groups are also relevant
apart from the workshop, and so should not be prescribed by it.  The
workshop can be viewed as an impetus for further consensual
infrastructure activities withing the temporal database community.

As a first step, coordinators are needed for each of these working
groups. I volunteer to coordinate a TSQL2 working group. I urge those
holding viewpoints (a) and (c) to consider coordinating a working
group consistent with your viewpoint.

Specifically, if you would be willing to coordinate the SQL2/3 working
group or the TSQL3 working group, I encourage you to volunteer.