This Question and Answer Set includes the following topics:
What kind of on-going maintenance does my Caché system require?
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 interrupt any processing. 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?
Structures used by Caché are 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 performance.
I want to set up disaster recovery for my Caché system. What do I need
to do?
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.
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.