Re: parallel backup and restore w onbar

Thanks Gustavo, The reason I want to do it is for speeding up the backups and restores. So if I'm hearing you correctly , as long as I don't have referential constraints, I should be good to go this way ? Thanks, floyd ----- Original Message ----- Subject: Re: parallel backup and restore w onbar Date: Tue, February 19, 2008 13:03 From: "Gustavo Castro" <gcastroc@bellsouth.net> I think you mean : > > "can I do parallel backup and restore on an instance that has ONLY > databases WITHOUT transaction logging?" > > As long as you backup the logical logs yes you can, but maybe you shouldn't: > > If your databases spawn more than 1 dbspace, and there are tables > related among the dbspaces, then the data will be logically corrupted, > take this example: > > - Instance with a single non-logging database named "mydb", created in > rootdbs. > - "mydb" has 2 tables : > + "parent" > + "child" > - You have a foreign key from child to parent. > - Each table is a different dbspace > > A parallel backup/restore will work, however the tables will probably be > out of syncs (You oculd get parents without children or children without > parent). > > This is becasue a parallel backup is in reality a dbspace backup. YOu > can only take snapshots of the dbspaces. > > Without logs there is no way to "glue" this backups to see the "whole > picture" > > > Gustavo > > > > > > > > > Floyd Wellershaus wrote: > > hello, > > In IDS10, using onbar, can I do parallel backup and restore on an > > instance that has no database transaction logging ? > > I think I should be able to, as long as I backup the logical logs and > > logs will need to be restored during a parallel restore. Is that correct ? > > > > ps. I realize I won't be getting schema changes that occurred since > > the last archive, but that's ok for now. > > > > Thanks, > > Floyd > > > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > Informix-list mailing list > > Informix-list@iiug.org > > http://www.iiug.org/mailman/listinfo/informix-list > > > > >

On Feb 19, 12:20 pm, "Floyd Wellershaus" <fl...@fwellers.com> wrote: > Thanks Gustavo, > The reason I want to do it is for speeding up the backups and restores. > So if I'm hearing you correctly , as long as I don't have referential > constraints, I should be good to go this way ? > > Thanks, > floyd > > ----- Original Message ----- > Subject: Re: parallel backup and restore w onbar > Date: Tue, February 19, 2008 13:03 > From: "Gustavo Castro" <gcast...@bellsouth.net> > > I think you mean : > > > "can I do parallel backup and restore on an instance that has ONLY > > databases WITHOUT transaction logging?" > > > As long as you backup the logical logs yes you can, but maybe you > shouldn't: > > > If your databases spawn more than 1 dbspace, and there are tables > > related among the dbspaces, then the data will be logically corrupted, > > take this example: > > > - Instance with a single non-logging database named "mydb", created in > > rootdbs. > > - "mydb" has 2 tables : > > + "parent" > > + "child" > > - You have a foreign key from child to parent. > > - Each table is a different dbspace > > > A parallel backup/restore will work, however the tables will probably be > > out of syncs (You oculd get parents without children or children without > > parent). > > > This is becasue a parallel backup is in reality a dbspace backup. YOu > > can only take snapshots of the dbspaces. > > > Without logs there is no way to "glue" this backups to see the "whole > > picture" > > > Gustavo > > > Floyd Wellershaus wrote: > > > hello, > > > In IDS10, using onbar, can I do parallel backup and restore on an > > > instance that has no database transaction logging ? > > > I think I should be able to, as long as I backup the logical logs and > > > logs will need to be restored during a parallel restore. Is that > correct ? > > > > ps. I realize I won't be getting schema changes that occurred since > > > the last archive, but that's ok for now. > > > > Thanks, > > > Floyd > > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > > Informix-list mailing list > > > Informix-l...@iiug.org > > >http://www.iiug.org/mailman/listinfo/informix-list I think I'd expand that to no fragmented tables, no detached indexes, no system catalogs in 1 dbspace while the tables reside in a different dbspace (so really 1 database and all it's tables contained in 1 dbspace), oh yeah, and no blobspaces, and possibly other things I can't think of off the top of my head. The way parallel backups work is the dbspaces each perform their own checkpoint (like the one that is done at the start of a non-parallel) so the phsyical logging that is done and checked for when archiving pages that are getting modified is different for each dbspace as they are archived in parallel. So if you don't have logical logging and logs to make sure all these different start points can sync up, you are really asking for the possiblity of something to get out of what, like a row that got inserted into a table, but the modification to the index page didn't make it (in the case of detached index in a different dbspace). I've seen more then 1 issue when a customer used parallel backups on non- logged databases that caused them consistency problems after a restore. In 11 the feature for parallel whole system archives was added. I really would try to avoid trying it on systems with non-logged databases before then, in a very specific sort of configuration you might be able to get it to work for you, but there are probably a lot more ways to have it not work then work. Jacques