Re: parallel backup and restore w onbar
- From: jprenaut@xxxxxxxxx
- Date: Tue, 19 Feb 2008 10:47:26 -0800 (PST)
On Feb 19, 12:20 pm, "Floyd Wellershaus" <fl...@xxxxxxxxxxxx> 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...@xxxxxxxxxxxxx>
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 youshouldn'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:correct ?
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
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...@xxxxxxxx
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
.
- References:
- Re: parallel backup and restore w onbar
- From: Floyd Wellershaus
- Re: parallel backup and restore w onbar
- Prev by Date: Re: parallel backup and restore w onbar
- Next by Date: Re: parallel backup and restore w onbar
- Previous by thread: Re: parallel backup and restore w onbar
- Next by thread: Re: parallel backup and restore w onbar
- Index(es):
Relevant Pages
|
