[sc34wg3] Comments on N448

Hiroyuki KATO sc34wg3@isotopicmaps.org
Tue, 25 Nov 2003 13:56:40 +0900

Hi there, my name is Hiroyuki Kato, and I'm a new member of SC34/WG3
from Japan. The following are my comments on N448. 

* In general, high level query languages must be declarative same as
SQL or XQuery is. So, add "TMQL must be declarative and must be
independent of any particular evaluation strtegy." to 4. Requirements
for the Language or a suitable section. 
"Declarative" means that answers are specified by properties they
satisfy, with no refernce to an algorithm for producing them[AHV95]. 

* TMQL should support grouping and aggregations functionality. Because 
TMQL is a high level language, TMQL is needed to have an explicit
expression to support grouping and aggregations. SQL has a GROUPBY
clause to support this, Datalog also has this introduced by
Mumick[MPR90] or Consens[CM90]. XQuery doesn't have an explicit
GROUPBY expression but has an expressive power with implicit GROUPBY
"4.1 Functionality" is briefy described. So, the granuality of
functionality is different from each of three functionality in 4.1,
but both AsTMa? and tolog don't mention this, as far as I know.

[AHV95] S.Abiteboul, et.al., "Foundations of Databases", Addison-Wesley, 
[MPR90] I.S.Mumick, et.al., "The magic of duplicates and aggregates",
	In Proc. of Intl. Conf. on Very Large Databses(VLDB), 1990.
[CM90]	M.P.Consens, et.al., "Low complexity aggregation in Graphlog
	and Datalog", In Proc. of Intl. Conf. on Database
	Theory(ICDT), 1990.
	W3C, "XPath 2.0 and XQuery 1.0 Issues", 
	http://www.w3.org/TR/2003/11/xpath-xquery-issues/, 2003.

Best Regards

Hiroyuki Kato / Ph.D
National Institute of Informatics, Japan.