Re: INFORMIX WISH LIST

My request has to do with a thread I posted recently: >It seems to me a glaring omission in the product that Informix does not >provide a way to migrate data from one machine to another - of a >different configuration, without having to incur significant downtime. >In this case, it seems the only option is to bring the old system down, >do a dbexport of the entire database, then do a complete dbimport on the >new system before we can bring up the new system. This would result in >over twelve hours of downtime given the amount of data this client has. >My client simply cannot afford that! What do other companies do in such >a case? I can't imagine that a bank moving to a new machine could bring >down their mission-critical ATM servers for a significant amount of >time, in order to migrate hardware. It just doesn't make sense to me. >Someone please tell me there is another way! As far as I can tell, the only way to migrate Online data to a new hardware platform while minimizing downtime is to use a utility which has logging: Ontape, Onarchive, Onbar. Load the 0-level archive onto the new machine, then just before you're ready to cut over, bring succeeding archives to the new machine and roll them forward. However, from my point of view, these utilities have a major problem. They require that the hardware you are migrating to have chunks configured the *same* as your original platform. This is an unreasonable constraint. Often, one of the elements of moving to a new system is to have increased disk capacity. And when increasing disk capacity, it is not reasonable to assume that you are going to partition the same way on a new system. Plus, migrating to a new system would be an ideal time to implement a different data distribution strategy. Given these constraints, in order to make such a move, one has to take the current database down (which many companies simply can't afford to do), unload with dbexport or such (time consuming). Then wait until the entire database has been restored to the new hardware (time consuming) before being back in business (this could cause a company to lose an entire day of business (or more, depending on the amout of data being migrated) - totally unacceptable). What is needed it the ability to make portable, logged archives. At the moment, I am absolutely agog knowing that this feature does not already exist. I wonder how other companies deal with this migration problem. Ironically, this ability does exist with the low-end SE server. One could dump data from tables, then run audit trails on the database tables. After loading the dump on the new machine, one could bring the old machine down, copy over the audit trails to the new machine, roll forward the changes with `recover table` and be back in business w/ minimum downtime. -- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Blah Blah Lounge - "Do You Have Something Smart To Say?" Cosmo Lee email: cosmo@echonyc.com Brooklyn, NY * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *