Re: HELP - Hardware mirroring versus dbms mirroring

}From: ckipp@vth1.vth.colostate.edu (Cathy Kipp) }Subject: Re: HELP - Hardware mirroring versus dbms mirroring }Date: Wed, 17 Aug 1994 09:03:53 +22305606 (MDT) }X-Informix-List-Id: <list.4531> } }Joe Lumbley writes: }->Hardware mirroring is usually best, as it's faster. Next is HP-UX. Last }->comes OnLine mirroring. OnLine mirroring contains a little bit of logic }->regarding how to handle chunks that are down, but with any luck the HPUX }->or hardware mirroring will never let OnLine see that situation anyway. } }Joe, }Not to disagree with an expert, but I think it's important to mention here that }while hardware mirroring may be faster with the OnLine engine, under the 6.0 }DSA engine, Informix miroring will offer some performance advantages. I haven't been controversial for a while, so why not now... Jon Bentley (or someone like him) said somewhere words to the effect that 'if you can simulate something in the language faster than the compiler does the same operation, the compiler writer has blown it badly'. I think much the same applies to disk mirroring -- if the O/S can't do it better than OnLine, then the O/S mirroring is probably defective. Yours, Jonathan Leffler (johnl@informix.com) #include <disclaimer.h>