PostgreSQL vs MySQL — SQL Technical Interview Questions & Answers

PostgreSQL vs MySQL

PostgreSQL vs MySQL

  • Both are SQL databases with tables, JOIN, and transactions. MySQL is common with PHP/LAMP and shared hosting. PostgreSQL is stricter on types and SQL standard, with strong JSONB and GIS. Neither is always faster.
  • Watch dialect: MySQL backticks vs Postgres quotes, AUTO_INCREMENT vs SERIAL/GENERATED, IF() vs CASE. Learn JOIN once; check engine docs for functions.
  • Trap: ‘X is always faster’. Trap: pasting MySQL-only SQL into Postgres.
  • On the example next to this theory: PostgreSQL vs MySQL: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Technical Interview Tip: Same SQL idea. Pick by team/hosting, not a winner slogan.

Code Examples for PostgreSQL vs MySQL

PostgreSQL vs MySQL — sample query

-- PostgreSQL vs MySQL
CREATE TABLE demo (
  id INTEGER PRIMARY KEY,
  label TEXT NOT NULL,
  qty INTEGER DEFAULT 0
);
INSERT INTO demo (id, label, qty) VALUES
  (1, 'alpha', 2),
  (2, 'beta', 5);
SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

PostgreSQL vs MySQL: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

How to Explain PostgreSQL vs MySQL to an Interviewer

MySQL vs PostgreSQL?

Both SQL RDBMS MySQL common on LAMP Postgres stricter types