Re: Core team statement on replication in PostgreSQL

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