100% Free
🎯 3200+ Questions. One Goal: Your Success Sign In Sign Up

What is the purpose of Statistics in SQL Server performance?

Expert MS SQL
Quick Answer Statistics contain column value histograms used by the optimizer to estimate result set sizes. Good statistics → accurate row estimates → good plan choices. The optimizer doesn't run your query to see how many rows come back — it trusts its statistics. Out-of-date stats from large data loads are a top cause of performance regression.

Answer

Statistics describe column data distribution. SQL Server uses them to estimate row counts and choose efficient plans. Outdated or missing statistics lead to poor estimates and unstable performance. Keeping statistics fresh is essential for reliable query optimization.

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.

Bookmark Add to Set Notes

Want to bookmark, take notes, or join discussions?

Sign in to access all features and personalize your learning experience.

Sign In Create Account

Source: SugharaIQ

Related Questions in MS SQL

(10 questions)
What is MS SQL Server and where is it commonly used?
Explain Database, Table, Row, and Column in relational terms.
What is a Primary Key and why is it important?
What is a Foreign Key and what problem does it solve?
What are Constraints in MS SQL?
What is Normalization and why do we use it?
Explain 1NF, 2NF, and 3NF briefly.
What is Denormalization and when is it used?
What is an Index and why is it important?
What is the difference between Clustered and Non-Clustered Index?
View All MS SQL Questions
Ready to level up? Start Practice