Re: object algebra

"Jean Morissette" <jean.morissette666_at_videotron.ca> wrote in message news:zWoZb.41788$%p3.867535_at_weber.videotron.net...
> Hi,
> In query processing, a ODBMS parse a OQL request in a query tree
> corresponding to object algebra. But, unlike relational algebra, there
> is no standard object algebra. So, could you help me to find some good
> object algebra please (example: link to research university)?
> Thanks
> Jean Morissette

Scientific community is funny: following the industry, in 90s it was obligatory to put OO tag to everything. Including query optimization. (Now the tune is XML, of course). Therefore, I find it quite frustrating to search for the state of the art subquery unnesting paper, for example, and find that it is really about query unnesting in the object databases. To put it bluntly, you find some "object algebra" in every second paper from that period, so I don't really undertand your difficulty here. The question is, of course, how practical these algebras really are, as often one discovers that those "advanced" query transformation techniques are unable to unnest a simple subquery in the select clause. Received on Fri Feb 20 2004 - 22:39:09 CET