What are the differences between primary and secondary indexing?

What are the differences between primary and secondary indexing?

Primary indexing is a method where the index is built on the primary key of a table, ensuring unique entries. Secondary indexing, on the other hand, allows for indexing on non-primary key columns, which can speed up queries that filter on those columns.

Can you give me an example of when to use secondary indexing?

Sure! If you have a table of customers and you often search by their last names, creating a secondary index on the last name column can significantly improve query performance.

Are there any downsides to using secondary indexing?

Yes, secondary indexes can consume additional storage space and may slow down write operations, as the index needs to be updated whenever data is modified.

How do I create a secondary index in SQL?

You can create a secondary index in SQL using the CREATE INDEX statement. For example: CREATE INDEX idx_lastname ON customers(last_name); This will create an index on the last_name column of the customers table.