databaseChangeLog:
  - changeSet:
      id: 004-create-messages
      author: you
      changes:
        - createTable:
            tableName: messages
            columns:
              - column: { name: id, type: BIGSERIAL, constraints: { primaryKey: true } }
              - column: { name: sender_id, type: BIGINT }
              - column: { name: receiver_id, type: BIGINT }
              - column: { name: content, type: TEXT }
              - column: { name: created_at, type: TIMESTAMP }
              - column: { name: is_read, type: BOOLEAN }