Digging the STAR_TRANSFORMATION_ENABLED parameter on Oracle database 12cR1 inside a PDB

When you think of a parameter that can help you out with star queries, this parameter is the STAR_TRANSFORMATION_ENABLED. According to the Oracle official documentation, it is described as the difference between a typical query and a star query, “A typical query in the access layer is a bond between the fact table and some number of dimension tables and is often referred to as a star query. In a star query, each dimension table is joined to the fact table using a primary key to foreign key join. Normally…

Optimizing star queries

DBMS_XPLAN.DISPLAY ALTER SESSION SET star_transformation_enabled=TEMP_DISABLE; Database Administration -> Database PL/SQL Packages and Types Reference -> 202 DBMS_XPLAN Database Administration -> Oracle Database Reference -> STAR_TRANSFORMATION_ENABLED brunors*The views expressed here are my own and do not represent those of my employer.* Hello, I’m Bruno — a dual citizen of Brazil and Sweden. I bring a global perspective shaped by experiences in both South America and Europe, with a strong focus on collaboration and innovation across cultures. I am a Computer Scientist, PhD Candidate in Information and Communication Technologies, focusing on Data…