To mirror or not to mirror

IDS 7.31.UC3 running on IBM RS6000 G40 running AIX 4.3.4. We have a fully mirrored system at the moment (in Standard Engine 5.x) that, at 7:00am each morning, the mirror is split so that reports can be executed against the copy, whilst the live system chugs on. The Mirrors are then re-established at 12:00 in the afternoon -= we have 5 hours where the mirror is not present. Splitting the mirrors only takes about 2 minutes - DB size approx. 170GB In the new system which we are converting to, we want to maintain mirroring at the AIX level but am un-sure as to how this will work with the OnLine instance - we don't want multiple instances of Informix running on the same engine. My question is:- Is there a way to configure a number of tables so that a snap-shot can be taken at a particular point in time (7:00am) such that reports can be executed against these copies. The tables are in excess of 10GB each and so we want a quick method of duplicating the tables - Is there a method within ALTER TABLE that can make a physical copy of a table very quickly ? Any/All suggestions welcome. S. Sent via Deja.com http://www.deja.com/ Before you buy.

sean.kelsey@2020log.com wrote: > > IDS 7.31.UC3 running on IBM RS6000 G40 running AIX 4.3.4. > > We have a fully mirrored system at the moment (in Standard Engine 5.x) > that, at 7:00am each morning, the mirror is split so that reports can > be executed against the copy, whilst the live system chugs on. The > Mirrors are then re-established at 12:00 in the afternoon -= we have 5 > hours where the mirror is not present. Splitting the mirrors only takes > about 2 minutes - DB size approx. 170GB > > In the new system which we are converting to, we want to maintain > mirroring at the AIX level but am un-sure as to how this will work with > the OnLine instance - we don't want multiple instances of Informix > running on the same engine. > > My question is:- > > Is there a way to configure a number of tables so that a snap-shot can > be taken at a particular point in time (7:00am) such that reports can > be executed against these copies. The tables are in excess of 10GB each > and so we want a quick method of duplicating the tables - Is there a > method within ALTER TABLE that can make a physical copy of a table very > quickly ? No. Why not run the reports on the live system? IDS can handle the load and certainly your new server is sufficiently faster than the old one that noone will notice anyway. Art S. Kagel

sean.kelsey@2020log.com wrote: > IDS 7.31.UC3 running on IBM RS6000 G40 running AIX 4.3.4. > > We have a fully mirrored system at the moment (in Standard Engine 5.x) > that, at 7:00am each morning, the mirror is split so that reports can > be executed against the copy, whilst the live system chugs on. The > Mirrors are then re-established at 12:00 in the afternoon -= we have 5 > hours where the mirror is not present. Splitting the mirrors only takes > about 2 minutes - DB size approx. 170GB 170 Gig on Standard Engine. This must be some sort of record! > In the new system which we are converting to, we want to maintain > mirroring at the AIX level but am un-sure as to how this will work with > the OnLine instance - we don't want multiple instances of Informix > running on the same engine. Can't see why it shouldn't work under Online, although it will be quite a different cup of tea from SE (just change DBPATH and you're laughing!). Firstly, your mirrored disks should be visible to your reporting server (if a separate reporting server is not feasible, forget it!). At 7 am, block your instance with a blocking checkpoint "onmode -c block". Stop mirroring. Then, unblock your primary instance with "onmode -c unblock". Now, do stuff at your reporting server to make the previously mirrored disks (of the primary server) visible under pre-specified paths. Start up the instance. Report away. At 12 noon, bring down the reporting instance. Re-establish hardware mirroring on primary. I'm sure there will be some nitty-gritties to look into. However, the above scenario was, more or less, a disaster recovery scenario in one of my previous sites. And it was tested to work! > My question is:- > > Is there a way to configure a number of tables so that a snap-shot can > be taken at a particular point in time (7:00am) such that reports can > be executed against these copies. The tables are in excess of 10GB each > and so we want a quick method of duplicating the tables - Is there a > method within ALTER TABLE that can make a physical copy of a table very > quickly ? You could use Enterprise Replication to copy data from the Primary to the Reporting. In a (very small!) nutshell, this is how it would work. Keep it running most of the time. Suspend at 7am. Resume at 12 Noon. Rudy