On Tue, 2005-09-13 at 10:45, Russ Brown wrote: > Simon Riggs wrote: > > Barry, > > > > You can use PITR to archive transaction logs to a second server that is > > kept in standby mode. > > > > This will cope with any number of tables and cope with dynamic changes > > to tables. > > > > This is fairly straightforward and very low overhead. > > Set archive_command to a program that transfers xlog files to second > > server. > > Then set restore_command on the second server to a program that loops > > until the next file is available. > > Switchover time is low. > > > > Apologies for going slighly off topic, but isn't this basically how > MySQL does replication? I ask because one of the arguments against > moving to PostgreSQL in my organisation is 'no replication out of the > box'. But if the above is true it seems that all that is required are a > couple of scripts to handle log transfer and you have a form of > replication out of the box right there. > > Or am I missing something? I don't know, but someone in your organization seems to be. Let me present it as a simple devil's choice, which would you rather have, proven replication, that works, but requires you to setup a secondary bit of software / system scripts (like rsync) but is tested and proven to work, or, an "out of the box" solution that is untested, unreliable, and possible unsafe for your data? Chosing a database because it has "out of the box" replication without paying attention to how it is implemented, how well it works, and what are the ways it can break is a recipe for (data) disaster. I've tested slony, and I know that for what we use it for, it's a good fit and it works well. I've tested MySQL's replication, and it simply can't do what I need from a replication system. It can't be setup on the fly on a live system with no down time, and it has reliability issues that make it a poor choice for a 24/7 enterprise replication system. That said, it's a great system for content management replication, where downtime is fine while setting up replication. But I wouldn't choose either because it was easier to implement. Being easy to implement is just sauce on the turkey. I need the meat to be good or the sauce doesn't matter. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
