This Question and Answer Set includes the following topics:

General

What kind of on-going maintenance does my Caché system require?

Not much.

Caché's default configuration parameters allow your system to accommodate more workload dynamically. For example, the database will expand automatically and you just need to make sure the CACHE.DAT file doesn't fill a disk over time.

It's good practice to run integrity checks periodically during off-hours just as you would for any database. There's never a reason to reorganize or defragment the database as all the data structures used by Caché are automatically self-balanced.

You may wish to look at the error logs in the Caché Control Panel daily to make sure that no problems creep up on you.

When do I have to stop my production Caché system?

Assuming that you don't need to shut down the computer for some reason, you only need to restart Caché to increase global or routine buffers. Most configuration options are dynamic and don't any processing to be interrupted. Licenses can be changed on the fly. New versions of Caché can be installed as new instances and users can be rolled over the new instance at a convenient time.

With other databases I have to periodically turn off the system. What about Caché?

As mentioned elsewhere, all the data structured used by Caché as self-balancing and do not suffer performance degradation over time. You never need to take a system down to rebuild or compress data or indices in order to regain peformance.

I want to set up disaster recovery for my Caché system. What do I need to do?

Refer to the High Availability guide.

What kind of journals does Caché maintain?

A before image and after image journal. If the computer crashes, the database structure is protected by applying the before image journal. The committed transactions are automatically rolled forward from the after image journal, although it may be unnecessary. Uncommitted transactions are rolled back from the after image journal. The before image journal is the CACHE.WIJ, or write-image-journal.

Refer to the High Availability guide for more information on journals.

What is the best way to back up my Caché database?

There are several strategies for system backup. Refer to the High Availability guide.

Does Caché support any type of system shadowing?

We strongly recommend using disk mirroring complemented by Caché shadow journaling. Refer to the High Availability guide.

Does the Caché system log errors?

Yes, but reader be warned. The log contains benign information, such as “No Such File” when an application does an OPEN with a timeout that fails, and relevant information.

Does Caché have any database integrity checking utilities?

Why sure. Use Control Panel and right click on a database. Please be aware that it may report false positives if the database is active.

What does a Caché system do when it starts up? Is there any kind of integrity check on start up?

There's no integrity check per se, but it does perform a roll-back and roll-forward as described above.