Arrays

Use for small fixed lists; prefer junction tables otherwise

type[]variableRecommended

Tags, labels, small fixed-size lists. Avoid for relationships.

Range

up to 1 GB total

Performance

Supports GIN indexes for containment queries. No foreign key support.

Comparison

Arrays vs junction tables: arrays are simpler for small, denormalized lists (tags, labels). For relationships with their own attributes or referential integrity, use a junction table.

SQL Example

CREATE TABLE articles (
  id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  tags text[] NOT NULL DEFAULT '{}'
);

CREATE INDEX ON articles USING gin (tags);