Showing posts with label Performance Tuning. Show all posts
Showing posts with label Performance Tuning. Show all posts

Tuesday, 26 December 2017

Datastage Job Extraction - Performance Tuning

Extraction from Database - 

Filtration
1) Try to have the constraints in the 'Selection' criteria of the jobs itself. This will eliminate the unnecessary records even getting in before joins are made.
2) Using a constraint to filter a record set is much slower than performing a SELECT … WHERE….er joins in SQL itself if possible.

Sorting - Try not to use a sort stage when you can use an ORDER BY clause in the database. 
Join - Always prefer joins in SQL itself if possible.

Friday, 22 December 2017

Datastage Performance Tuning

Performance Tuning in ETL (Datastage) can be done in 3 different levels -

Architecture Level 
Information Server Architecture
Installation settings
Project level settings