If you’ve worked with PostgreSQL for a while, you’ve probably reached a point where a simple query slowly turns into something much bigger. It starts with a couple of joins, then another subquery, followed by a GROUP BY, and before long you’re scrolling through dozens of lines trying to remember what each part of the query is doing. I’ve been in that situation more times than I’d like to admit. Most of us learn SQL by mastering the fundamentals. We write SELECT statements, jo

A step-by-step guide to solving SQL queries using ER diagrams. Learn how to identify relationships, apply joins, and write accurate SQL queries.

Learn what Data Analysis is, its different types, the complete data analysis process, and the role of a data analyst. Discover how organizations transform raw data into actionable insights for better decision-making and business growth.

SQL stands for Structured Query Language. It is the standard language used to communicate with databases. Think of a database as a digital storage system where information is organized into tables. Few are some of the examples that SQL can helps us with: Retrieve data Insert new data Update existing data Delete unwanted data Analyze information Database: A database is an organized collection of data stored electronically. Instead of keeping data in spreadsheets or paper files

SQL NULLs often behave unexpectedly and can silently change query results. This blog explores common null traps in filtering, aggregates, subqueries, joins, and more—with practical examples and fixes.

Introduction Have you ever wondered what are null values in data? Honestly, before diving deep, I assumed they were equal to zero, if I encountered them in numeric columns and if in text columns, simply nothing. As a result, I ended up with mismatched numbers, wrong visualizations. My worst nightmare! I got baffled, but I was sure that this must do something with these null values and I decided to learn more about them and their behavior so I can be confident that the

Hello everyone! Welcome to another Interesting Tech Update on Analytics! Recently, I came across an interesting update about chDB in the TDLR Newsletter, which motivated me to explore it further. Until now, I’ve mostly worked with server‑based SQL engines such as PostgreSQL, MySQL, and SQL Server. I’ve also used serverless SQL engines on many challenge platforms like DataLemur, LeetCode, and HackerRank. These platforms typically use in‑process SQL engines, which don’t

In today’s digital world, almost every application relies on data — and SQL is one of the most important tools used to manage it. From small websites to global enterprises, SQL enables systems to store, organize, and retrieve information efficiently. If you’re stepping into technology, analytics, or data-driven decision-making, learning SQL is an essential first step.

Geospatial Data in modern digital systems Geospatial data has become a cornerstone of modern digital systems. From ride‑sharing apps and logistics platforms to urban planning tools and environmental monitoring systems, location‑aware data powers decisions across industries. Geospatial data represents objects, events, or phenomena that have a location on Earth. This location can be expressed in many ways: Points (e.g., a store location) Lines (e.g., a road or river) Polygon

PostgreSQL indexes are like the index at the back of a book—they help you find information fast without reading every page. When your database tables grow large (think thousands of rows), queries without indexes force PostgreSQL to scan every single row looking for matches. This "sequential scan" takes seconds or even minutes. Indexes create a separate, sorted reference structure that points directly to matching rows, dropping query times from seconds to milliseconds. Think o

Learn how PostgreSQL window functions enable advanced data analytics without collapsing rows. This blog uses the Titanic dataset to demonstrate ranking, running totals, segmentation, and trend analysis using real-world SQL examples.

Why Regex? - A Smart Filter Standard SQL search tools like LIKE or ILIKE as a simple "Ctrl+F" on your computer. They are great if you are looking for a specific word or a simple prefix, but they are clumsy when things get messy. For example, if you need to find every email address in a database, a simple search can't distinguish between a valid email format and a random string containing an "@" symbol. This is where PostgreSQL Regular Expressions (POSIX) comes in. Regex is l

From NON - IT to Data Analytics... Could This Be Your Story Too? Photo by Deng Xiang on Unsplash Have you ever sat at your desk and thought, “I’m doing my job well… but is this really what I want to do long term?” If yes, trust me you’re not alone. I was working in the financial sector , handling daily operations, transactions, and reports. Everything was stable. Everything was familiar. But somewhere along the way, I started noticing something interesting, every decision wa

What is JSON: The Universal Language of Data Exchange In today’s digital world, applications constantly communicate with each other—mobile apps talk to servers, websites fetch data from APIs, and backend systems integrate with third‑party services. At the heart of much of this communication is JSON, short for JavaScript Object Notation. Despite its name, JSON is not limited to JavaScript; it has become a universal, language‑independent format for storing and exchanging data.

Introduction: The Analytical Pivot In my previous post, we treated the Student Performance Dataset like a digital training ground. We focused on the "how" of data cleaning—scrubbing text, fixing nulls, and standardizing schemas. It was the perfect exercise for a data "workbench" setup. However, as a former Clinical SAS Programmer, I know that cleaning is only half the battle. The true value of a database isn't just in its cleanliness; it’s in its ability to act as an analyti

Power BI turns that data into insights that can be put to use, while SQL serves as the framework for data management. This blog describes how combining the two platforms creates robust, interactive enterprise reporting dashboards.

Hey Everyone, Happy to connect you all once again through my writing...! Recently I have come across a situation...

PostgreSQL, a powerful open-source relational database, offers many features that simplify backend development and data handling. One...

Postgresql data types description.

Joins Joins in the data world means combining two tables horizontally. Join functions/queries help us to consolidate two separate tables...