Db2 for z/OS: DDF, zIIP Engines, and SMT2

SQL statements executed by way of the Db2 for z/OS distributed data facility (DDF) are not, of course, the only workload that uses zIIP MIPs, but in my experience this does tend to be the main driver of zIIP utilization in a z/OS system on which Db2 runs. I posted an entry to this blog, a few years ago, on the importance of avoiding zIIP engine contention . In that blog entry, I described how to calculate the "zIIP spill-over ratio" for a Db2 DDF workload (the percentage of zIIP-eligible …read more