Answer
Implicit conversions prevent index usage by forcing SQL Server to convert values at runtime. This leads to scans instead of seeks, higher CPU usage, and slower joins. Matching data types between columns and parameters is vital.
Quick Answer
Implicit conversion happens when two columns being compared have different data types — SQL Server silently converts one. This often makes the comparison non-SARGable, forcing a full scan instead of a seek. Common: comparing nvarchar column to a varchar parameter. Always match data types in joins and WHERE clauses.
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