Answer
Extra columns increase:
- Index size
- Maintenance overhead
- Memory usage
Indexes should be narrow and purpose-specific.
Quick Answer
Every non-clustered index duplicates the clustered key columns as the row locator. Wide index keys = larger index pages = more I/O to scan the index. Narrow indexes fit more entries per page, require less memory in the buffer pool, and are faster to scan. Only index the columns you actually need for your queries.
S
SugharaIQ Editorial Team
Verified Answer
This answer has been peer-reviewed by industry experts holding senior engineering roles to ensure technical accuracy and relevance for modern interview standards.
Want to bookmark, take notes, or join discussions?
Sign in to access all features and personalize your learning experience.
Source: SugharaIQ