Fwd: framework question

From the right ID this time ....

Begin forwarded message:

On 07/07/2004, at 10:29 PM, Joe Pluta wrote:

This is the type of bollix I'd really like to keep off this list.

As opposed to the bollocks you spout under the guise of <MODERATOR ALERT>?

Having journaling and commitment control may indeed be more reliable
than not having them. However, there is a price to pay in terms of disk
space and performance. That price is essentially the cost you pay for
insurance against hard disk crashes.

I really should know better ... however ... you don't get something for nothing. Even doing it the roll-your-own way has a cost. I don't know about you but DASD is much cheaper than my time--even at IBM prices.

DASD space usage can be managed by changing journal receivers regularly. DASD arm usage can be managed by putting receivers on dedicated drives. The 5% or so CPU overhead I would accept as a reasonable payment for guaranteed database integrity.

But I forget. You could write a secure safe reliable transaction processor in less time than the rest of us could eat lunch so the programmer cost would be negligible. (Oscar was right about sarcasm.)

So, once again, this is NOT a philosophical issue, it's a business
decision. Does it make sense to spend the money on commitment control?
How often does your machine have a hard crash?

Exactly, it is a business decision. How much does it cost your business to allow programmers the luxury of reinventing integrity mechanisms when the system already provides such features. How much does it cost your business when a crash occurs? How long can you afford to be down while someone verifies the database is intact?

This is another example of "past behaviour being no indication of future performance". Just because a hard crash is unlikely doesn't mean you shouldn't plan for such an event nor do what you can to minimise the impact. Especially when a small amount of development investment in applying commitment control and a small amount of cost for DASD and CPU can guarantee recovery to a known point.

Regards,
Simon Coulter.
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