Kjell,
> > Or a more automated and built-in support to do such a > replicate/backup/restore/reverse. For me it's question of time. Sure, I > could learn how to setup a cluster and replication. But there are dozens > of other things I also need to do yesterday, so having to learn this on > top of everything else is a stumbling block. > > Could the procedure be "packaged" into some kind of utility program or > something? The short answer is probably just "No." Could someone build a robot that would identify a flat tire, take your spare tire out of your trunk, jack up your car, remove the flat, put on the spare, lower the care, and put the flat tire back in the trunk? Probably. Would it be easier than learning to change a tire? Somewhat unlikely. On a heavily loaded system, the replicated database (replicant in my jargon) can't share a disk and set of set of cpu's with the primary database. (That's the trunk part of the analogy.) Once established, the replicant has to create a foundation copy of the primary database (jacking up the car), then process updates until it's approximately current current with the primary database (removing the old tire), then initiate a backup/restore, wait for the restore to complete successfully(install the new tire), swap in the newly created database and catch up to the primary again (lower the car). Finally, once the newly restored replicant is absolutely current, the system must quiesce for a few seconds to swap primary and replicant databases (getting the old tire into the trunk). > > I'm thinking that nbackup locks the master file while keeping track of > changed pages in a separate file. Perhaps a transaction id consolidation > similar to what happens on backup/restore could be performed on a locked > database master while logging updates in a separate file, and then bring > the consolidated master up to date again. nbackup works at the page level which is simpler than handling record level changes. Unlike records, pages never go away, nor do they change their primary identifier. > If this is very difficult, perhaps there's no point - devel resources > better spent elsewhere. But if it would be a fairly simple task...? Alas, I doubt that its simple. Best regards, Ann ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
