[net.database] UNIFY and MISTRESS

mas@charlie.OZ (Mike Steel) (11/13/85)

Deakin University, here in Geelong, Australia, have just completed a
3 month evaluation of two database products, UNIFY and MISTRESS.
Our decision is to go with UNIFY for a rewrite of some fairly large
administration systems but it was not clear cut; MISTRESS (alias
MS/32) has a lot going for it.

	Points in favour of MISTRESS were:
1. It has transaction backout in a program, UNIFY hasn't.
2. Its user interface (MBUILDER) supports windowing.
3. It supports logical views (i.e. virtual tables).
4. You can call SQL directly from a MISTRESS/C program.
5. UNIFY is restrictive (max record length, max field size).
6. UNIFY 'standard' data entry can't cope with more fields than will
	fit on one screen (even DBASE2 doesn't suffer from this!).
7. UNIFY does unnecessary i/o in that a record being updated gets
	written back once for each field that is changed!!!!!

	Points in favour of UNIFY were:
1. The user base is much bigger, at least in Australia.
2. It has a nice flexible menu interface for both user and 
	programmer contrasting with MISTRESS's difficult-to-use
	interface for schema and security changes.
3. The UNIFY pre-join is worth a lot (for both database consistency
	and at least in theory performance).
4. Much better UNIFY performance using report scripts (other
	performance tests came out about equal)
5. Better programmer control over locks (we think).
6. Much easier to get it working with different terminal types.
7. With MISTRESS you code a lot of your application in a new
	non-standard language (MBUILDER) whereas with UNIFY you
	get by with just C and SQL.
8. UNIFY can give you a lot of database statistics if you want them.

The most important factor for us was the large UNIFY user base (we
don't have any pioneering spirit here!). But despite our decision
we still have reservations about UNIFY and hope very much that 
before our first big system goes live in two years UNIFY will
have cured the problems of:
	- unnecessary i/o when modifying records,
	- lack of transaction backout (within and outside programs).

Mike Steel, Computer Centre,	From Australia: mas@charlie.oz
Deakin University, Victoria,	UUCP:	!decvax!mulga!charlie.oz!mas
3217 Australia.			APAR:
Tel. (0)52-471152		 munnari!charlie.oz!mas!SEISMO.ARPA