DB2 Understanding Elapsed Time
MICS
Metrics

In DB2, elapsed time is an important measurement because it is used for several purposes. From the end-user perspective, it is commonly considered as the response time of a thread. For the DB2 analyst, it is used in correlation with other critical metrics, such as CPU time and I/Os for performance analysis. For query CP parallelism, it is helpful to know the elapsed times of each individual parallel task because it might help to determine how parallelism is balanced. For example, does every subtask have an "equal amount" of the total work in terms of I/Os CPU, and so on.
micsrm140cd
In DB2, elapsed time is an important measurement because it is used for several purposes. From the end-user perspective, it is commonly considered as the response time of a thread. For the DB2 analyst, it is used in correlation with other critical metrics, such as CPU time and I/Os for performance analysis. For query CP parallelism, it is helpful to know the elapsed times of each individual parallel task because it might help to determine how parallelism is balanced. For example, does every subtask have an "equal amount" of the total work in terms of I/Os CPU, and so on.
The 
MICS
 files that provide several data elements that are related to elapsed time measurements are the DB2 User Activity (DB2DSU) and DB2 Plan Activity (DB2DSP) files. Accurate reporting on threads elapsed time requires a good understanding of the content of these variables, as soon as parallel processing is involved.
 
Contents of Elapsed Time Data Elements for the DB2DSU/DB2DSP Files
 
 
Element Name
 
 
Sequential Processing
 
 
Parallel Processing
 
fffELPTM
thread total elapsed time
parent task elapsed time only
fffET2TM
thread total elapsed time
parent task elapsed time only
fffPELPT
zero
sum of all child tasks elapsed times
fffPET2T
zero
sum of all child tasks elapsed times
fffTELPT
thread total elapsed time
sum of parent and all child tasks elapsed times
fffTET2T
thread total elapsed time
sum of parent and all child tasks elapsed times
For guidelines on how to use these data elements under different perspectives, see DB2 Data Analysis Guidelines.