Thumb Rule for Secondary Indexes Per Table

This question confuses SQL developers, but there is a simple rule for creating secondary indexes.

Secondary Indexes on Table

If you see in any database, all the databases(RDBMS) supports only one primary index. So no database allows more than one primary index. But, you can have more than one secondary index.
The limit for secondary index is 5
More than 5 secondary indexes, reduces performance of a SQL query on that table

Srini

Data Engineer with deep AI and Generative AI expertise, crafting high-performance data pipelines in PySpark, Databricks, and SQL. Skilled in Python, AWS, and Linux—building scalable, cloud-native solutions for smart applications.