# Data Engineering
All Data Engineering notes →1 — SQL Foundations
Foundational SQL — SELECT, JOIN, GROUP BY, HAVING, UNION, CASE expressions, and EXISTS — as the baseline every later SQL chapter builds on.
2 — Advanced SQL
Advanced analytical SQL — window functions, ranking, running totals, recursive queries and recursive CTEs, pivoting, and common table expressions.
3 — Query Optimization
How a query planner turns SQL into an execution plan — reading execution plans, index usage, predicate pushdown, partition pruning, join strategy selection, and cost-based optimization.
# Dbms
All Dbms notes →1 — SQL Basics
Covers the SQL language families — DDL, DML, DCL, TCL — along with core data types and constraint syntax.
2 — Querying Data
Covers the fundamental query clauses — SELECT, WHERE, ORDER BY, LIMIT, DISTINCT, LIKE, IN, BETWEEN, and CASE expressions.
3 — Joins
Compares inner, left, right, full, self, cross, anti, and semi joins and how each changes a query's result set.
4 — Aggregation
Covers GROUP BY, HAVING, aggregate functions, and multi-dimensional aggregation via ROLLUP, CUBE, and GROUPING SETS.
5 — Subqueries
Covers scalar and correlated subqueries and the EXISTS, NOT EXISTS, ANY, and ALL predicates.
6 — Common Table Expressions
Covers recursive and non-recursive common table expressions and their use in querying hierarchical data.
7 — Window Functions
Covers the OVER() clause and ranking/offset window functions — ROW_NUMBER, RANK, DENSE_RANK, LEAD, LAG, FIRST_VALUE, and LAST_VALUE.
8 — Advanced SQL
Covers views, materialized views, stored procedures, functions, triggers, sequences, and identity columns.