Rule Definition
A query that retrieves all columns of a table with a SELECT * can potentially be the source of important changeability problems. One cannot control how the columns will be ordered and returned to the client. This can lead to important data inconsistencies and thus stability issues. Also performance problems may arise when the execution of the query returns a large result sets (many row with all the columns may then become a huge amount of data to transport over the network). Thus optimizer module can't provide a correct execution.

Remediation
Review the design of the query to select only useful columns.

Violation Code Sample

https://docs.oracle.com/middleware/1221/bip/BIPDM/best_practices.htm#CHDIBFEE

SELECT * FROM EMPLOYEES;

Fixed Code Sample

https://docs.oracle.com/middleware/1221/bip/BIPDM/best_practices.htm#CHDIBFEE

1. Always select only the columns you need:
SELECT DEPARTMENT_ID, DEPARTMENT_NAME FROM EMPLOYEES;

or

2. Use a WHERE clause and bind parameters whenever possible to restrict the returned data more precisely:
SELECT DEPARTMENT_ID, DEPARTMENT_NAME 
FROM EMPLOYEES 
WHERE DEPARTMENT_ID IN (:P_DEPT_ID)

Oracle® Fusion Middleware Data Modeling Guide for Oracle Business Intelligence Publisher Only Return the Data You Need https://docs.oracle.com/middleware/1221/bip/BIPDM/best_practices.htm#CHDIBFEE Google Cloud BigQuery - Optimize queries - Optimize query computation https://cloud.google.com/bigquery/docs/best-practices-performance-compute#avoid_select_ Top five query tuning techniques for Microsoft SQL Server - Don't select everything https://www.dbvis.com/thetable/top-five-query-tuning-techniques-for-microsoft-sql-server/ Snowflake Query Optimization Techniques - 1. Select fewer columns https://select.dev/posts/snowflake-query-optimization#1-select-fewer-columns Medium Blog - 5 Reasons Why Using SELECT * in SQL Queries Should be Avoided https://medium.com/@pradeeptiwari.bhumca10/5-reasons-why-using-select-in-sql-queries-should-be-avoided-1417ef433a92