David Fetter wrote:
This part is a deal-killer. It's a giant up-hill slog to sell warm standby to those in charge of making resources available because the warm standby machine consumes SA time, bandwidth, power, rack space, etc., but provides no tangible benefit, and this feature would have exactly the same problem. IMHO, without the ability to do read-only queries on slaves, it's not worth doing this feature at all.
I don't think I agree with this. There are a large number of situations where it's positive expectancy to do precisely this- it's not unlike buying a $1 lottery ticket with a 1 chance in 100 of winning $1000- the vast majority of the time (99 times out of 100), you're going to lose $1. But when you win, you win big, and make up for all the small losses you incurred getting there and then some. Failover machines are like that- most of the time they're negative value, as you said- taking up SA time, bandwidth, power, rack space, money, etc. But every once in a (great) while, they save you. If the cost of having the database down for hours or days (as you madly try to next-day replacement hardware) isn't that great, then no, this isn't worthwhile- but in cases where the database being down chalks up the lost money quickly, this is easy to cost-justify.
Being able to do read-only queries makes this feature more valuable in more situations, but I disagree that it's a deal-breaker.
Brian
