Building upon the section about 'Proper Indexing,' this article would explore advanced indexing techniques beyond the basics of clustered, non-clustered, and covering indexes. The advanced concepts would include: partial indexes (indexing only a subset of the data), filtered indexes (useful for specific query patterns), expression-based indexes (indexing the result of a function or expression), and using specialized index types like spatial indexes (for location-based data) or full-text indexes (for text searching). The follow-up article would also discuss the importance of index maintenance (rebuilding or reorganizing indexes) to prevent fragmentation and performance degradation over time. It would also touch upon the trade-offs of having too many indexes (increased write overhead) versus not enough (slow read queries). Furthermore, the article will address the challenges in indexing JSON or unstructured data and offer best practices for dealing with complex data types.