This is one of the most frequently asked DataStage interview questions for freshers in recent times. This answer is specifically a part of DataStage performance tuning interview questions. For performance tuning of the DataStage job, the following practice must be used -  Using Job Monitor – Provides a handy snapshot of a job's performance at a particular point in time during execution.  Using Score Dump - Score Dump produces a report that displays and provides information about operators, processes, and records within a job.  Using Resource Estimates - Used to determine necessary system requirements.  Performance Analysis Usage - Collect data during job execution. (Note: This option is disabled by default). When activated and a job is opened, a new toolbar option called Performance Analysis  Additionally, selecting the correct configuration files, partitions and buffers. Handling sorting the data and handling zero-time values. You should try to copy, modify, or filter instead of using transformers. Need to reduce unnecessary metadata proliferation between phases.