SQL Interview - Advanced Level
For senior developers with 4+ years of SQL experience. Master query optimization, execution plans, database design, partitioning, replication, and performance at scale.
35-45 minutes
4+ years of SQL experience
Who is this for?
Senior database engineers
Backend architects
Data engineers at scale
Those preparing for senior/staff data roles
What you'll practice
Reading and optimizing execution plans
Designing effective index strategies
Architecting scalable databases
Implementing partitioning
Understanding replication
Performance tuning at scale
Topics covered
Query Optimization
Execution plans (EXPLAIN)
Query rewriting
Statistics and planner
Performance profiling
Advanced Indexing
B-tree vs Hash indexes
Composite indexes
Covering indexes
Index strategies
Database Architecture
Partitioning strategies
Replication
Sharding
Connection pooling
Scalability
MVCC
Lock types
Transaction isolation levels
Vacuum and maintenance
Example questions
Q:
How do you read and optimize an EXPLAIN plan?
Q:
What index strategy would you use for this query pattern?
Q:
How does partitioning improve query performance?
Q:
Explain MVCC and transaction isolation levels
Q:
How would you design a database for 100M+ rows?
Q:
What are the trade-offs between normalization and denormalization?
Preparation tips
Master EXPLAIN and query plans
Study index types and strategies
Learn partitioning approaches
Understand replication and sharding
Practice optimization at scale
Study database internals
Continue your journey
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