Re: buffered logging - sybase vs. informix

>From: john b <jointprd@crl.com> >Date: Mon, 18 Mar 1996 13:22:06 -0800 >X-Informix-List-Id: <news.22233> > >First some background info - I'm a Sybase DBA with a potential INFORMIX >project coming up. So... I'm reading my INFORMIX DBA SURVIVAL Guide and >I come across the section on buffered logging. I think this is pretty >cool stuff - Sybase doesn't have this. At the same time I'm thinking of >potential uses for buffered logging. The only thing that really comes to >mind is static info. like a DSS database. So my question are: > >1) how many folks are actually using buffered logging? I've used it in the past, mainly on databases with a low update volume where the update activity was not mission critical (read-mainly databases). >2) has anyone experienced loss of data? Yes, but not often. It requires the machine or OnLine to crash out of control, and the logs not to have been flushed to disk since the last commit. This is (should be) relatively rare, not least because the hardware is pretty reliable these days. But by definition, if you are using buffered databases, this data loss is not significant. If it is significant, you should not use buffered databases. >3) can you actually force the buffers to disk via a "checkpoint"? Of course. Also by using SET LOG. But, as stated previously, if your database is buffered, you have concluded that the risk of lost data is not significant. >[...Request for Sybase-Informix comparison omitted...] Yours, Jonathan Leffler (johnl@informix.com) #include <disclaimer.h>