Performance Tiuning Against Db2 on Cloud

Changes in SQLs while migrating from Oracle to DB2 to improve performance:

  • Instead of nvl or coalesce function use case statement
  • Instead of using select clause within select statement, create joins with sub queries
  • Don't use subqueries in where clause
  • Creating small tables for required columns and joining them results in faster performance
  • Use "AS" to qualify names
  • Define Amount Type to decimal(15,2) to match with DB. They may be dropped while doing aggregations.

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