PostgreSQL Get Started
🐘 PostgreSQL Get Started
PostgreSQL (often called Postgres) is a powerful, open-source relational database known for reliability, performance, and advanced SQL features.
It’s widely used in web apps, analytics, and enterprise systems.
1️⃣ What is PostgreSQL?
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Open-source RDBMS
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Uses SQL (with many advanced extensions)
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ACID compliant (safe transactions)
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Supports JSON, indexing, stored procedures
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Runs on Windows, Linux, macOS
📌 Used by companies like Apple, Reddit, Instagram.
2️⃣ Why Choose PostgreSQL?
✔ Advanced SQL & indexing
✔ Excellent performance & stability
✔ Strong data integrity
✔ Scales well (small → enterprise)
✔ Free & community-driven
3️⃣ Install PostgreSQL (Quick Steps)
Windows / macOS / Linux
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Download from postgresql.org
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Run installer
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Set:
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Superuser password
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Port (default 5432)
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Finish installation
You’ll get:
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PostgreSQL Server
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pgAdmin (GUI tool)
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psql (command-line tool)
4️⃣ pgAdmin vs psql ⭐
| Tool | Type | Use |
|---|---|---|
| pgAdmin | GUI | Beginners, visual management |
| psql | CLI | Fast queries, scripting |
5️⃣ Connect to PostgreSQL
Using pgAdmin
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Open pgAdmin
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Register Server
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Enter:
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Host:
localhost -
Port:
5432 -
Username:
postgres -
Password
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Using psql (CLI)
6️⃣ Create Your First Database
Connect to it:
7️⃣ Create a Table
📌 SERIAL auto-increments IDs.
8️⃣ Insert Data
9️⃣ Read Data
🔟 Update & Delete
⚠️ Always use WHERE to avoid affecting all rows.
1️⃣1️⃣ PostgreSQL Data Types (Basics)
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INTEGER,SERIAL -
VARCHAR,TEXT -
BOOLEAN -
DATE,TIMESTAMP -
JSON,JSONB
1️⃣2️⃣ PostgreSQL vs MySQL ⭐ (Interview)
| Feature | PostgreSQL | MySQL |
|---|---|---|
| Standards | Very strict | Flexible |
| JSON | Advanced (JSONB) | Basic |
| Indexing | Powerful | Good |
| Use case | Complex apps | Simple apps |
📌 Common Beginner Mistakes ❌
❌ Forgetting to connect to DB before queries
❌ Not using SERIAL for auto IDs
❌ Missing WHERE in UPDATE/DELETE
❌ Confusing pgAdmin with server
🎓 Interview / Exam Questions
Q1. What is PostgreSQL?
👉 An open-source relational database.
Q2. Default PostgreSQL port?
👉 5432
Q3. What is SERIAL?
👉 Auto-increment integer type.
Q4. GUI tool for PostgreSQL?
👉 pgAdmin
✅ Summary
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PostgreSQL is a powerful open-source RDBMS
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Install → Connect → Create DB → Create tables
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Use pgAdmin (GUI) or psql (CLI)
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Supports advanced SQL & JSON
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Great for web, analytics, enterprise apps
