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MySQL & MariaDB

MySQL & MariaDB

v1.0.0

Lint MySQL and MariaDB schemas, queries, and migrations for performance, security, and best practices.

14 rules

4 categories

Performance(8)

Use Online DDL for ALTER TABLE

ALTER TABLE in MySQL can lock the entire table. Use ALGORITHM=INPLACE or tools like gh-ost for safe migrations.

Online DDLMySQLMigration Safety

Security(1)

Use prepared, parameterized statements

Bind user input as parameters rather than concatenating it into SQL strings.

Quality(4)

Use the InnoDB storage engine

Use InnoDB for transactions, foreign keys, and row-level locking instead of MyISAM.

Enable strict SQL mode

Run with STRICT_TRANS_TABLES so invalid or out-of-range values error instead of silently changing.

Choose the narrowest correct column types

Pick the smallest data type that fits the domain instead of defaulting to BIGINT or wide VARCHAR.

Architecture(1)

Use utf8mb4 Instead of utf8

MySQL's utf8 charset only supports 3-byte characters. Use utf8mb4 for full Unicode support.

MySQLSchema DesignMariaDB

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Index All Foreign Key Columns

Unlike PostgreSQL, MySQL/InnoDB requires indexes on foreign key columns. Missing indexes cause slow JOINs.

MySQLMariaDBDB Linting

HIGH

Use EXPLAIN to verify query plans

Run EXPLAIN on slow or important queries to confirm indexes are used and scans are bounded.

Set an appropriate transaction isolation level

Choose an isolation level (e.g. READ COMMITTED) that matches your concurrency and consistency needs.

Index columns used in JOIN, WHERE, and ORDER BY

Add indexes on columns that appear in join conditions, filters, and sort clauses.

Keep WHERE clauses sargable

Avoid wrapping indexed columns in functions so the optimizer can use the index.

Avoid SELECT * in Production Queries

SELECT * fetches all columns, wasting bandwidth and preventing covering index optimization.

MySQLQuery Optimization

Avoid implicit type conversions in comparisons

Compare columns against values of the same type to avoid silent casts that disable indexes.

Define foreign keys for referential integrity

Declare FOREIGN KEY constraints so the database enforces valid references between tables.

MEDIUM

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Rules Skills Knowledge Prompts

Pricing Blog Contributors Install Guide

MySQL & MariaDB Linting

Review skill for MySQL and MariaDB databases covering schema design, query optimization, migration safety, and security hardening.

Tools Covered

SQLFluff — SQL linting and formatting (MySQL dialect)
Squawk — Migration safety analysis
pt-query-digest — Query performance analysis (Percona Toolkit)
mysqlcheck — Table integrity verification
gh-ost / pt-online-schema-change — Safe online DDL
SchemaHero — Declarative schema management

Applicable Platforms

MySQL 8.x
MariaDB 10.x / 11.x
Amazon RDS for MySQL / Aurora MySQL
Google Cloud SQL for MySQL
Azure Database for MySQL
PlanetScale
TiDB