This article explains why ordinary unique constraints fail with soft‑deleted rows, and shows how to maintain email uniqueness by using partial unique indexes in PostgreSQL or generated‑column‑based unique indexes in MySQL/MariaDB, including multi‑tenant adaptations.
This article reveals eight powerful, lesser‑known MySQL 8.0 features—including window functions, descending indexes, generated columns, invisible indexes, optimizer hints, resource groups, LATERAL JOIN, and multi‑valued JSON indexes—showing how they dramatically improve query performance and simplify complex SQL tasks.
This guide explains why MySQL cannot index JSON columns directly and demonstrates two practical work‑arounds—using generated columns in MySQL 5.7 and functional indexes in MySQL 8.0.13—to efficiently index a nested request.email field for fast queries.
The article explains how to improve indexing of long string columns in MySQL by using generated columns with CRC32/MD5 hashes, functional indexes introduced in MySQL 8.0.13, and prefix indexes, providing code examples and performance considerations.
