On Feb 5, 2007, at 12:47 , Warren Turkal wrote:

Is anyone working on a period data type as described in Dr. Richard Snodgrass' book _Developing Time-Oriented Database Applications in SQL_[1]? I did not
see a relevant project listed in the TODO. I would like to contribute
(possible funding and/or coding) the development of a conforming
implementation of this data type.

[1]http://www.cs.arizona.edu/~rts/tdbbook.pdf


This is an area I'm actively working on. I've worked out an example using composite types and PL/pgsql, though it's not very performant. I'm currently looking at making a contrib module, but have been slowed a bit by my lack of C experience. Regarding conformance, as there's currently no standard, I'm leary of cleaving too closely to the Temporal SQL proposal to ward of making something that would be close but not quite conformant to a future addition to the SQL standard. Also, I hope to make a more general interval/range/period constructor that would allow you to make "periods" of other types (say, integers) as well. I've found Date/Darwen/Lorentzos' Temporal Data and the Relational Model[1] very helpful.

Interested in possibly working together?

Michael Glaesemann
grzm seespotcode net

[1]http://books.elsevier.com/uk/mk/uk/subindex.asp?isbn=9781558608559

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