IBM 000-8697 Chapter 5 How to Improve Performance

Table of Contents xi
Chapter 5 How to Improve Performance
In This Chapter .................. 5-3
Disk Layout ................... 5-4
Optimize Blobspace Blobpage Size ........... 5-5
tbcheck -pB and tbcheck -pe Utility Commands...... 5-5
Blobpage Average Fullness............. 5-7
Apply Effective Criteria .............. 5-8
Eliminate User-Created Resource Bottlenecks ........ 5-8
When Is Tuning Needed? ............... 5-10
% Cached Fields ................ 5-10
ovtbls, ovlock, ovuser, and ovbuff Fields ........ 5-11
Bufsize Pages/IO Fields.............. 5-11
Shared-Memory Buffers ............... 5-13
When Is Tuning Necessary? ............ 5-13
How Is Tuning Done? .............. 5-13
Shared-Memory Resources .............. 5-14
When Is Tuning Necessary? ............ 5-14
How Is Tuning Done? .............. 5-15
Log Buffer Size .................. 5-15
Logging Status ................. 5-15
How Is Tuning Done? .............. 5-16
Page-Cleaner Parameters ............... 5-17
Efficient Page Cleaning .............. 5-17
How Is Tuning Done? .............. 5-19
Checkpoint Frequency ................ 5-20
Performance Tradeoffs .............. 5-20
How Is Tuning Done? .............. 5-21
Psort Parallel-Process Sorting Package .......... 5-22
How Psort Works ................ 5-22
Tuning Psort.................. 5-23
Psort and Shared Memory ............. 5-24
SPINCNT Configuration Parameter ........... 5-24