semantics of QBE

Thread View: net.database

2 messages

[T] Back to Threads [V] Tree View [G] Group Articles

2 total messages Started by Dale Thu, 30 Jan 1986 18:05

#172

Author: Dale
Date: Thu, 30 Jan 1986 18:05

23 lines
1475 bytes

	I am looking for a statement of the formal semantics of QBE. I
	have read the paper "Query-by-Example: a data base language" by
	M.M. Zloof (IBM Syst. J., #4, 1977) which is one of the early
	published descriptions of QBE. That paper presents QBE by
	means of (what else!) examples. That's sufficient for the easy
	cases, but I'm uncertain of the meaning of queries involving
	aggregates or (in Ingres terminology) aggregate functions.
	And queries that involve joins on sets are completely unclear
	to me.

	There is a paper entitled "Algorithm for Processing Query by
	Example" by Niebuhr et al (IBM Tech. Disc. Bull., vol. 19 #2)
	which helps a little, but assumes the reader already understands
	the semantics.

	Anyway, any pointers to papers will be muchly appreciated.

	Dale Brayden
	Scientific Computer Center, DS 50-454
	Tektronix, Inc.
	P.O. Box 500
	Beaverton, OR  97077

Re: semantics of QBE

#177

Author: johnl
Date: Mon, 03 Feb 1986 22:51

9 lines
962 bytes

/* Written  1:05 pm  Jan 30, 1986 by Dale@tektronix in ima:net.database */
> I am looking for a statement of the formal semantics of QBE.

QBE turned into a product.  Ask your IBM salesman for "Query-by-Example
Terminal User's Guide," SH20-2078.  It is as close to a formal definition
as there seems to be, and has reasonable syntax charts and definitions.

John Levine, ima!johnl

Thread Navigation

This is a paginated view of messages in the thread with full content displayed inline.

Messages are displayed in chronological order, with the original post highlighted in green.

Use pagination controls to navigate through all messages in large threads.

Back to All Threads