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  1. Preface
  2. Change Data Capture Introduction
  3. PowerExchange Listener
  4. PowerExchange Condense
  5. DB2 for i5/OS Change Data Capture
  6. Remote Logging of Data
  7. Introduction to Change Data Extraction
  8. Extracting Change Data
  9. Monitoring CDC Sessions
  10. Managing Change Data Extractions
  11. Tuning CDC Sessions
  12. Appendix A: DTL__CAPXTIMESTAMP Time Stamps

CDC Guide for i5/OS

CDC Guide for i5/OS

Example 2. UOW Count and Time-Based Commits

Example 2. UOW Count and Time-Based Commits

This example uses the
UOW Count
and
Real-time Flush Latency in milli-seconds
attributes to control commit processing. The change data consists of UOWs of varying sizes.
The following table describes the commitment control attribute values that this example uses:
Attribute
Value
Maximum Rows Per commit
0, which disables this attribute
Minimum Rows Per commit
0, which disables this attribute
Real-time Flush Latency in milli-seconds
5000, which is equivalent to 5 seconds
UOW Count
1000
Initially, PWXPC reads 900 complete UOWs in 5 seconds. Because the real-time flush latency interval has expired, PWXPC flushes the data buffer to commit the change data to the targets. PWXPC then resets both the UOW counter and real-time flush latency timer. When PWXPC reaches UOW 1,000, PWXPC does not commit change data to the targets because the UOW counter was reset to 0 after the last commit.
PWXPC reads the next 1,000 UOWs in 4 seconds, which is less than the real-time flush latency timer. PWXPC commits this change data to the target because the UOW counter has been met. After this commit, PWXPC then resets the real-time flush latency timer and the UOW counter.
PWXPC continues to read change data and commit the data to the targets, based on the UOW count or the real-time flush latency flush time, whichever limit is met first.
In this example, PWXPC commits change data at the following points:
  • After UOW 900 because the real-time latency flush latency timer matched first.
  • After UOW 1,900 because the UOW count matched first during the second commit cycle.

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