Strange display of READ EFF in BUFFER POOL list display panel for Sysview for Db2

Products

• SYSVIEW Performance Management Option for DB2 for z/OS

Issue/Introduction

The Sysview for Db2 for z/OS (IDB2) Buffer Pool List displays the value of Read Eff as *******.
What does this mean?

Resolution

READ EFF stands for Read Effectiveness and is the ratio of Getpage requests to Synchronous I/O operations. When Synchronous I/O value is
0 (zero) and getpage value is NON ZERO, since you cannot divide by zero, that is when the value of Read Eff is displayed as ********.