On Fri, Jun 01, 2007 at 12:39:42PM -0400, gonzales@xxxxxxxxxxxxxx wrote: > ever need? I say yes, I can. BUT it would so much cooler IF, > there was a multi-master environment configured for the sake of > doing it. Yes, it would be. Unfortunately, when I was in the position where I had to explain to my bosses that we still didn't have any demonstrable progress after a couple of years of effort and expense, they told me they weren't willing to continue funding that work. I presume other people had similar experiences with their bosses. Moreover, because we had something else that solved our _particular_ problem -- i.e. zero-transaction-loss failure recovery within our SLA -- it was hard to justify the continued work. > I'm glad that not everyone has this disposition about 'why do we > need it.' The pursuit of knowledge is the facilitator of > innovation. Others have argued that necessity is the mother of invention. I have no idea what causes better software in general; what I know is that, for companies that are likely to spend money to pay people to work on multimaster replication, a strong need and evidence of progress are two necessary conditions. Bruce mentioned (at PgCon in Ottawa) that one of the UCB people, in handing the project off, said that Postgres needed a few people with a lot of time rather than a lot of people with a little time. Multimaster replication is like that, and therefore finding someone who will work on it (either because they're paid to or because they are incapable of leaving the problem alone) is going to be the requirement to get it done. > Why? Because I'd like to. My point was really to ask, "How much do you want it?" If the answer to that is, "Enough to use it when someone else shows up with the goods," then I'm trying to suggest that that's not enough to cause the happy result you desire. Someone needs to do the work, which means that someone has to want the result badly enough to put the time and talent into getting the result. > would not be deterred from using Postgresql because it doesn't have a > quote unquote, 'multi-mater' replication. It is certainly true today that if what you really need is RAC, you have exactly one company to go to, and that's Oracle. If you need something else, there might in fact be a Postgres answer for you. Part of the problem here is that people often say "multimaster" without stating what they're asking for. Does MySQL have multimaster replication? Well, yes and no, depending on which set of features you might want to use and what data breakage you're willing to tolerate. What about SQL Server? See above. Ok, what about DB2? Well, no, not really, but it scales well and you can do HA with it using hot-standby failover clusters at the OS level, if you believe their literature. There's also some component that sort of hangs on the side and does some data synchronisation between points, allowing something that looks like multimaster but sounds like it has some nasty gotchas (and I get that feeling just from reading the brochures. OTOH, I am not completely rational when it comes to claims made by IBM). You can in fact build a Postgres system that does the same things today, though. These are all different solutions to different problems, so it's not surprising that they look different. This was the reason I asked, "What is the problem you are trying to solve?" A -- Andrew Sullivan | ajs@xxxxxxxxxxxxxxx Unfortunately reformatting the Internet is a little more painful than reformatting your hard drive when it gets out of whack. --Scott Morris
