Secondary Indexes Per Table: Thumb Rule

This is the question twists SQL developers. Here is a thumb rule for it.

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


Author: Srini

Experienced software developer. Skills in Development, Coding, Testing and Debugging. Good Data analytic skills (Data Warehousing and BI). Also skills in Mainframe.