The Code With Raman
blog.
Deep dives on SQL, Python, data modeling, ERWIN, and what it actually takes to land and grow a data engineering career.
SQL Window Functions: ROW_NUMBER, RANK, DENSE_RANK, and Running Totals Explained
Window functions are one of the most powerful — and most feared — features in SQL. This guide walks through every major window function with practical examples: ranking, running totals, moving averages, and the classic "second highest salary" interview question.
RANK() OVER (ORDER BY salary DESC)
AS salary_rank,
SUM(salary) OVER (ORDER BY id)
AS running_total
FROM employees;
-- ┌──────────┬────────┬─────────────┬───────────────┐
-- │ name │ salary │ salary_rank │ running_total │
-- ├──────────┼────────┼─────────────┼───────────────┤
-- │ Alice │ 90000 │ 1 │ 90000 │
-- │ Raman │ 85000 │ 2 │ 175000 │
25 Claude Pro Tips Every Engineer & User Should Know in 2026
The definitive guide to getting 10× more out of Claude — Projects setup, XML prompt structure, API cost tricks, Claude Code shortcuts, Ollama routing, and hidden features 80% of users never discover.
Claude Code — The CLI Coding Agent That Reads Your Entire Codebase
Install Claude Code, set up CLAUDE.md for your project, run agentic mode, and integrate with VS Code or JetBrains. With real data engineering use cases — dbt models, Airflow DAGs, and SQL refactoring.
Ollama + Claude: Run Local AI Models Free and Route Smartly
Install Ollama, pick the right model for your hardware, connect it to Claude Code via MCP, and build a Python router that uses local models for bulk tasks and Claude for quality work.
CDM vs LDM vs PDM: What's the Difference and Why It Matters in Interviews
Every data architect interview asks some version of "explain the difference between conceptual, logical, and physical data models." Here's exactly how to answer it, with examples from a real e-commerce schema built in ERWIN.
Python List Comprehensions: 10 Patterns Every Developer Should Know
List comprehensions are Python's most elegant feature — and the one most developers underuse. From simple filters to nested loops to conditional transforms, here are 10 real-world patterns with before-and-after code.
Star Schema vs Snowflake Schema: Which Should You Choose and When?
Both patterns organize data warehouses around a central fact table — but their trade-offs are real. This post breaks down storage, query performance, maintenance overhead, and which major cloud warehouses favor each pattern.
How to Crack the Data Engineering Interview in 2026: What They Actually Ask
After reviewing hundreds of data engineering interviews, here's what's changed and what hasn't: SQL window functions, data modeling theory, pipeline design, cloud fundamentals, and the behavioural questions most candidates underprepare for.
ERWIN Forward Engineering: Generate Production-Ready SQL in 5 Minutes
Most people use only 20% of ERWIN's forward engineering options. This walkthrough covers the full options dialog — what to check, what to skip, and how to generate clean DDL that runs without modification on PostgreSQL, SQL Server, or Oracle.
SQL JOINs Visual Guide: INNER, LEFT, RIGHT, FULL OUTER with Real Examples
JOINs are the most asked-about SQL topic in interviews. This visual guide explains each type with a consistent example dataset so you can see exactly which rows appear and why — including the anti-join pattern most developers miss.
Java OOP Interview Questions: Polymorphism, Encapsulation, and Inheritance Explained
The four pillars of OOP always come up in Java interviews. This post gives you precise, technical answers — not textbook definitions — for the questions that trip most candidates: abstract class vs interface, method overloading vs overriding, access modifiers.
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