PostgreSQL Notes Visualized for Data Analytics

Do you know how to master data retrieval and logic in PostgreSQL? FROM, SELECT, and Logical Operators are the three building blocks behind every SQL query you have ever written. I illustrated the full picture. Follow Nitin Rawat for daily PostgreSQL content 🔔 #PostgreSQL #SQL #LearnSQL #BackendDevelopment #Database #SQLForBeginners

🗄️ Slow query? Stop guessing. EXPLAIN ANALYZE shows you exactly what Postgres did, not what you think it did. 🔍 Seq Scan on a big table = missing index. Simple as that. #PostgreSQL #SQL #Database #Backend #WebDev

SQL, Database, and RDBMS — how are they actually connected? Explained in under 1 minute. Watch the video above. Follow Nitin Rawat for daily PostgreSQL content 🔔 #SQL #PostgreSQL #RDBMS #Database #LearnSQL #BackendDevelopment

🚀 PostgreSQL Architecture — Simple Flow Every DBA Should Know 👇 🔹 Step 1: Client sends query App / psql → SQL query sent to server 🔹 Step 2: Postmaster (Connection Manager) Accepts connection & creates a backend process 🔹 Step 3: Backend Process One process per user → Parses, plans & executes query 🔹 Step 4: Shared Memory (Performance Zone 🚀) • Shared Buffers → Cache data • WAL Buffers → Store changes 👉 If data is already in memory → super fast ⚡ 🔹 Step 5: WAL (Data Safety Rule) Before writing actual data: 👉 First write to WAL 👉 Then write to data files 💡 This is why PostgreSQL is crash-safe 🔹 Step 6: Background Processes • WAL Writer → Writes logs • Checkpointer → Flushes data to disk • Autovacuum → Cleans dead rows 🔹 Step 7: Disk Storage • Data Files (tables/indexes) • WAL Logs 🔥 Golden Rule: 👉 First WAL → Then Data 💡 Final Flow Check: Client → Postmaster → Backend → Memory → WAL Flush → [Success/Result to Client] → Background Checkpoint → Data Files. #PostgreSQL #DBA #Database #Architecture #SQL #Learning #Tech

SQL Fundamentals Series (PostgreSQL Edition) — Part 1 👍 Every SQL query starts with one command: SELECT In relational databases, SELECT is used to retrieve data from a table. When working with databases such as PostgreSQL, this is the primary way analysts and engineers explore stored data. For example, imagine a table called customers. To retrieve specific columns from that table SELECT first_name, last_name FROM customers; SELECT first_name, last_name FROM customers; 😊 This query tells the database: Return the first_name and last_name columns from the customers table. One habit many beginners develop is writing: SELECT * FROM customers; While this works, retrieving all columns is rarely ideal in real-world systems. In large datasets, selecting only the columns you need helps improve efficiency and keeps queries cleaner. Small habit. Better queries. #SQL #PostgreSQL #DataEngineering #DataAnalytics

Databases power every modern app and digital business. In this video, learn the fundamentals of Database Management Systems, relational databases, SQL, and the differences between MySQL, PostgreSQL, and NoSQL databases. Understand how data is organized, protected, and used to build reliable software and scalable digital platforms. #Databases #SQL #MySQL #PostgreSQL #NoSQL #TechEducation #SoftwareDevelopment

Relational databases are the foundation of SQL systems. Understanding Primary Keys and Foreign Keys is essential for structuring and analyzing data. Swipe through this carousel to see how these concepts work in PostgreSQL and BigQuery. #SQL #RelationalDatabases #DataAnalytics

PostgreSQL DBAs — stop writing SQL just to explore your database. These psql meta commands will save you time every single day: \l → databases \dt → tables \d table → structure \timing → query speed \x → expanded view \? → everything No complex queries. Just backslash and go. 🚀 📖 Want more commands like these? Explore the full cheat sheet here 👇 🔗 https://lnkd.in/gMZkBhC5 #PostgreSQL #mafiree #DBA #Database #SQL #DataEngineering #DevTips #BackendDev #OpenSource

𝗗𝗮𝘆 𝟭𝟬 - 𝗧𝗢𝗣 / 𝗟𝗜𝗠𝗜𝗧 𝐄𝐯𝐞𝐫𝐲 𝐝𝐚𝐭𝐚 𝐩𝐫𝐨𝐟𝐞𝐬𝐬𝐢𝐨𝐧𝐚𝐥 𝐞𝐯𝐞𝐧𝐭𝐮𝐚𝐥𝐥𝐲 𝐦𝐞𝐞𝐭𝐬 𝐨𝐧𝐞 𝐥𝐚𝐧𝐠𝐮𝐚𝐠𝐞: 𝐒𝐐𝐋 TOP (SQL Server) or LIMIT (MySQL, PostgreSQL) is used to control how many rows a query returns. It’s helpful when you want to preview a small portion of large datasets, check the first few records, or quickly inspect your data without fetching everything. #SQL #DataSkills #DataAnalytics #LearningInPublic #THE_Africa_Idealist #30DaysOfSQL #30DaysSQLCards

"Built a complete Grocery Delivery DB in PostgreSQL — 6 tables, real data, 25 SQL queries from basic to advanced. Sharing for anyone learning SQL! Honestly? I don't know everything yet. Some queries I wrote myself. Some I struggled with. Some I took help to understand. But that's exactly where I am right now — learning, practicing, and being consistent. This document has all 25 queries sorted Easy → Hard, with the schema and everything clean. #SQL #PostgreSQL #DataAnalytics #LearningInPublic #SQLPractice #DataAnalyst