SQL DB

Database index 

Fill Factor:

Understanding SQL Server Index Fill Factor Setting 

Index creation SQL:

SQL - Indexes - Tutorialspoint 

Inde architecture type:

Relational Algebra - Tutorialspoint 

Relational Algebra Introduction - scranton 

Relational Algebra - juniata 

SQL JOINS - w3resource 

Relational Algebra 

Jeffrey D. Ullman 

Database Systems: The Complete Book 

OLAP-Online analytical processing - Wikipedia 

Cubes - OLAP Framework — Cubes 1.0.1 documentation 

Apache Pinot 

Apache Kylin 

Database normalization - Wikipedia