Performance Tuning for Content Manager

188 Performance Tuning for Content Manager

Valid values are:

0 No diagnostic data captured

1 Severe errors only

2 All errors

3 (default) All errors and warnings

4 All errors, warnings, and informational messages

Increasing the amount of diagnostic output can result in both performance

degradation and insufficient storage conditions in your database instance file

system if that is where your diagnostics file is stored.

Our recommendation

Because the file will continue to grow forever and consume space, it is necessary

to maintain the file. Instead of manually editing the file to crop it down or simply

deleting it, we recommend that you periodically move (manually or via a

scheduled script) the file to another disk. (DB2 will automatically create a new

db2diag.log file.) Each moved file would overlay the previously moved file,

allowing for one version of historical data.

8.3.7 Cleaning up the event log

An event monitor captures system monitor information after particular events

have occurred. These include the end of a transaction, the end of a statement, or

the detection of a deadlock. This information can be written to files or to a named

pipe. If you have Events enabled, monitor the size of the Events table and

periodically prune it.

8.4 SMS to DMS table space conversion

As discussed in 2.2.4, “Performance-related tools and concepts” on page 63,

there are distinct advantages related to whether to use system-managed storage

(SMS) table spaces or database-managed space (DMS) table spaces. As a

general rule, a well-tuned set of DMS table spaces outperforms SMS table

spaces for reasons such as:

 Assigning indexes to separate table spaces from the base table.

 The ability to add or extend containers.

 Does not use the file system of the operating system.

It is not necessary or advisable for all of your table spaces to be converted to

DMS. DMS is recommended for tables that have a high volume of activity or have

a high cardinality. A Content Manager system that has a lot of users concurrently

accessing the system and retrieving data would benefit from DMS table spaces.