postgresql/no-alter-column-type

Why this matters

PostgreSQL may need to rewrite every row (and every index) under an `ACCESS EXCLUSIVE` lock to change a column's type. For non-trivial tables, add a new column, dual-write, backfill, and swap — or wrap the conversion in a separate, scheduled migration.

Examples

ALTER TABLE users ALTER COLUMN id TYPE bigint;

ALTER TABLE users ADD COLUMN id_new bigint;

ALTER TABLE users ALTER COLUMN status SET DEFAULT 'active';

Configure it

// eslint.config.js
import postgresql from "eslint-plugin-postgresql";

export default [
  {
    files: ["**/*.sql"],
    languageOptions: {
      parser: postgresql.configs.recommended.languageOptions.parser,
    },
    plugins: { postgresql },
    rules: {
      "postgresql/no-alter-column-type": "warn",
    },
  },
];

Options

This rule has no options.