Path: utzoo!attcan!uunet!husc6!mailrus!tut.cis.ohio-state.edu!mandrill!hal!ncoast!allbery
From: allbery@ncoast.UUCP (Brandon S. Allbery)
Newsgroups: comp.databases
Subject: Re: Raw partitions (was: Re: Unix machines for large databases)
Message-ID: <7977@ncoast.UUCP>
Date: 13 Jun 88 23:24:53 GMT
References: <564@hscfvax.harvard.edu> <3102@edm.UUCP> <2728@geac.UUCP> <7873@ncoast.UUCP> <573@hscfvax.harvard.edu>
Reply-To: allbery@ncoast.UUCP (Brandon S. Allbery)
Followup-To: comp.databases
Organization: Cleveland Public Access UN*X, Cleveland, Oh
Lines: 37

As quoted from <573@hscfvax.harvard.edu> by pavlov@hscfvax.harvard.edu (G.Pavlov):
+---------------
|   Sorry, I was obscure in my followup.  My question related to a more basic
|   issue:  are these two dbms's "faster" than those that do not avail them-
|   selves of this "feature" ?  Or is it used to compensate for an overall
|   design that otherwise produces second-rate performance ?
+---------------

A little of both.  There *is* a speed penalty derived from using ordinary
Unix files, courtesy of indirect blocks (triple indirect blocks can KILL
database response speed!).  Unify has never advertized particularly loudly,
but they've had raw databases since at least 3.0, which was out in 1984.
Since Unify is generally pretty fast anyway in my experience, raw databases
only add to the already-existing speed.

Oracle is well known to have problems with batch-style transactions, which
is why Oracle Corp. is releasing a new SQL processor for batch transactions.
Without the new SQL (which is IN ADDITION TO the standard SQL, not replacing
it!) you have to use raw database to get any semblance of speed in batch
transactions.

Informix-SQL isn't very fast, either.  (I've used identical applications on
the same computer running under Informix-SQL 2.10 and Informix 3.30; the
pre-SQL Informix is much faster.)  However, it is faster than Oracle in at
least some circumstances; it's passable for most work.  But it takes a
MASSIVE speed hit when files get into double indirection (so does 3.30, it
appears to be an artifact of C-ISAM), which Informix-Turbo is supposed to
cure.  So here it's a little of both.

I couldn't say about others; I've never used them.  (Well, a little Dbase III+
-- as little as possible -- but MS-DOS doesn't have raw devices so it's a
moot point.)
-- 
Brandon S. Allbery			  | "Given its constituency, the only
uunet!marque,sun!mandrill}!ncoast!allbery | thing I expect to be "open" about
Delphi: ALLBERY	       MCI Mail: BALLBERY | [the Open Software Foundation] is
comp.sources.misc: ncoast!sources-misc    | its mouth."  --John Gilmore