Read comprehensive guides and interactive tutorials for Python and SQL. Each guide focuses on tracing variable states, tracking memory references, and writing optimized logic for coding screens.
Master INNER, LEFT, RIGHT, FULL, and CROSS JOINs with query execution patterns, visual tables, and interview-grade edge cases.
June 16, 2026
Deep dive into ROW_NUMBER, RANK, DENSE_RANK, and analytical offsets (LEAD/LAG) with practical interview questions.
June 18, 2026
Understand Common Table Expressions, subqueries, recursion, performance implications, and readability benefits.
June 20, 2026
Learn COUNT, SUM, AVG, MIN, and MAX aggregations, how GROUP BY works under the hood, and the difference between WHERE and HAVING.
June 22, 2026
Master SQL query optimization questions. Learn B-Tree indexing, execution plans, and query tuning for interviews.
June 24, 2026
Master all three types of SQL subqueries - scalar, table-valued, and correlated - with real interview question patterns and performance considerations.
July 1, 2026
10 practical SQL query optimization techniques. Learn B-Tree indexing, CTE tuning, and EXPLAIN plan reading for interviews.
July 22, 2026
Master SQL window functions for data engineering interviews. Learn PARTITION BY, ORDER BY, ROWS/RANGE frame specifications, and performance.
July 30, 2026