How to Tune Performance for Reports

SQL query tuning can improve the performance of reports. Diagnose issues and an explain plan. Here are some factors that can slow down query performance, and some suggestions for improvement.

Factor	Description	Suggestions
Filters	Reports with no filters or filters that allow a large volume of data may hurt performance.	Use filter conditions to limit data.
Joins	Reports that join a lot of tables can run slowly.	Remove any unnecessary joins.
Data volumes	Reports with no filters or filters that allow a large volume of data may hurt performance.	Add filter conditions to limit data, preferably using columns with database indexes. Use caching for small tables.
Indexes	Filters that use database indexes can improve performance.	Use SQL hints to manage which indexes are used.
Sub-queries	Sub-queries can impact performance.	Avoid complex sub-queries and use Global Temporary Tables where necessary. Avoid too many sub-queries in where clauses if possible. Instead, rewrite queries with outer joins.
Aggregation	It helps performance to prioritize aggregation in the database.	Use Oracle SQL Analytical functions for multiple aggregation. Use CASE statements and DECODE functions for complex aggregate functions.