DB01922W - BEST PRACTICE SUGGESTION - recommendations
Article ID: 238551
Updated On:
Products
Issue/Introduction
During the Datacom MUF startup various DB01922W - BEST PRACTICE SUGGESTION messages are issued.
DB01922W - BEST PRACTICE SUGGESTION - 6) DATAPOOL DATA2 LT 1000, TARGET 1K-20K
DB01922W - BEST PRACTICE SUGGESTION - 9) FLEXPOOL NE 0, TARGET 0
DB01922W - BEST PRACTICE SUGGESTION - 24) HISTORY MISSING
DB01922W - BEST PRACTICE SUGGESTION - 25) LOGRCV SET AS YES/NEVER
What needs to be changed? What are the recommendations and how to test?
These are the current values for these options:
DB01900I - DATAPOOL 4K,6K,32767,300 DATA BUFFER SIZE,# OF BUFFERS,
DB01900I - * LARGE DATA BFR SIZE,# LARGE BUFFERS
DB01900I - FLEXPOOL 100,100,100,100 BUFFERS FOR IXX, DXX, DATA, LARGE DAT
DB01900I - LOGRCV NEVER LOG RECOVERY FILE AVAILABLE
Environment
z/OS
Cause
The best practices are suggestions to make option changes to what is considered best practice for best performance. Read about the Best Practice messages in documentation section New MUF SYSPRINT Messages for Best Practices
The best practice message is described in the documentation for message DB01922W.
Resolution
The messages are just suggestions so you don't need to make the changes. The system will still work with the current startup options.
If you decide not to make a change, individual best practice suggestions can be turned off with the MUF startup parameter BEST_PRACTICES_OFF nn.
Where nn is the best practice number from message DB01922W. See Article 1152 for more details.
The first 2 suggestions are to make the MUF perform better so you can't really test unless you keep statistics before and after the change. There is a discussion of database buffers in section Optimizing Datacom/DB Performance
DB01922W - BEST PRACTICE SUGGESTION - 6) DATAPOOL DATA2 LT 1000, TARGET 1K-20K'
The DATA2 number of buffers is recommended to be at least 1000, so change the DATAPOOL statement to:
DATAPOOL 4K,6K,32767,1000 DATA BUFFER SIZE,# OF BUFFERS,
DB01922W - BEST PRACTICE SUGGESTION - 9) FLEXPOOL NE 0, TARGET 0
It's not recommended to have FLEXPOOL buffers defined at startup so remove the following:
FLEXPOOL 100,100,100,100 BUFFERS FOR IXX, DXX, DATA, LARGE DAT
DB01922W - BEST PRACTICE SUGGESTION - 25) LOGRCV SET AS YES/NEVER
The following statement indicates no recover file is available so no forward or backward recovery is possible:
LOGRCV NEVER LOG RECOVERY FILE AVAILABLE
Is this a production system, or even a test system you would want to have recovery available.
To enable recovery change the LOGRCV option to specify an inactive Recovery File:
LOGRCV NO
DB01922W - BEST PRACTICE SUGGESTION - 24) HISTORY MISSING
This history database stores historic information on the Datacom MUF. See documentation of this in section Creating and Maintaining the History Database.
You enable it by specifying the HISTORY statement plus some others.
HISTORY 1007 HISTORY DATABASE DBID
HISTORY_END_HOUR 00 00-24 HOUR TO COLLECT HISTORY
HISTORY_EVENT_TABLE YES SUPPORT FOR EVT
Additional Information
Also see Article 201601 - Dealing with DB01922W BEST PRACTICES messages with the ENF IMUF
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