sql Archives - ITNotes

Mastering DuckDB: The Fast In-Process OLAP Database for Serverless Analytics

October 7, 2026

Analyze large CSV and Parquet files instantly without spinning up database servers. This tutorial demonstrates how DuckDB provides serverless, in-process OLAP performance for fast local analytics and cross-source queries.

Database

Scaling PostgreSQL for Time-Series Data with TimescaleDB: A 6-Month Production Review

October 5, 2026

Struggling with slow time-series queries and index bloat in PostgreSQL? Here is how we migrated 1.2 billion IoT records to TimescaleDB, cut write latency from 450ms to 6ms, and reduced disk usage by 87%.

Database

Mastering SQL Window Functions: Real-World Guide to ROW_NUMBER, RANK, LEAD, and LAG

October 4, 2026

Learn how to use SQL window functions like ROW_NUMBER, RANK, LEAD, and LAG to debug real-world production incidents, deduplicate records, and compute running analytics efficiently.

Database

SQL Refactoring: How to Convert Nested Subqueries to CTEs for Better Performance and Readability

September 14, 2026

Deeply nested SQL subqueries are hard to read, debug, and maintain. This guide shows you how to convert them to Common Table Expressions (CTEs) step by step, with real before/after examples and performance verification tips for PostgreSQL and MySQL.

Database

Advanced Vietnamese Search in PostgreSQL and MySQL: Collation, Unaccent, and Index Optimization

September 14, 2026

Vietnamese diacritics break naive database search queries. Here's how to configure Collation in MySQL and the Unaccent extension in PostgreSQL — plus functional and GIN indexes — so searches work correctly without a performance hit.

Database

PostgreSQL Performance: Speed Up Queries with Covering Indexes

September 10, 2026

Boost PostgreSQL performance by eliminating heap access. Learn how to use Covering Indexes, the INCLUDE clause, and the Visibility Map to reduce I/O.

Database

Querying PostgreSQL, MySQL, and MinIO with Trino: A Single SQL Interface for Multi-Source Data Analysis

August 24, 2026

Learn how to use Trino to run federated SQL queries across PostgreSQL, MySQL, and MinIO S3. This guide covers setup, configuration, and performance tips for multi-source data analysis without ETL.

Database

Deploying QuestDB on Docker: A Guide to High-Velocity Time-Series Data

August 2, 2026

Scale your IoT or Fintech data with QuestDB on Docker. This guide covers high-speed ingestion, SQL optimization, and a direct comparison with InfluxDB and TimescaleDB.

Database

GitOps for Databases: Using Bytebase to Automate SQL Reviews and Prevent Downtime

August 1, 2026

Stop risking production downtime with manual SQL scripts. Learn how to implement a GitOps workflow using Bytebase to automate database reviews, linting, and deployments.

Stop Fighting Regex: Build an Intelligent ETL with LLMs and Pydantic

July 28, 2026

Ditch fragile Regex. Learn how to build a modern ETL pipeline that converts messy, unstructured text into clean, validated SQL data using Python, GPT-4o, and Pydantic.