DB2 SQL Query Performance Tuning (2 of 3)

In DB2, the role of Senior software developers is performance tuning. The real point is where you need to focus. I have discussed key areas where you need to focus on.

Advantages of tuning or Performance

  1. reduces CPU time utilization
  2. application running cost you can reduce.

Five Top areas you need to focus to improve performance

1. Right Access Path…

Here, how to find right access path.

  1. Access path determined by during bind time
  2. Access path at execution time
  3. Read more tuning ideas if you want to know more here

2. Statistics update…

  • DB2 checks catalog statics updated or not. So that it determines right access path
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3. Index…

  • DB2 checks clustering index defined on any tables, which access so frequently

4. SQL query written in simple way…

  • SQL query should be as simple as possible
  • Avoid GROUP BY and ORDER BY
  • Avoid unused columns

5. Avoid Sorts in SQL query…

  • Use Indexes correctly, instead Sorting methods..like GROUP BY or ORDER BY etc

Also read

Author: Srini

Experienced software developer. Skills in Development, Coding, Testing and Debugging. Good Data analytic skills (Data Warehousing and BI). Also skills in Mainframe.