The tables of a library of files (Storehouse.Ecto.Blob, Storehouse.Ecto.Usage), for a migration of the app's:

defmodule MyApp.Repo.Migrations.AddStorehouseBlobs do
  use Ecto.Migration

  def up, do: Storehouse.Ecto.Migrations.up()
  def down, do: Storehouse.Ecto.Migrations.down()
end

It makes two tables:

• storehouse_blobs - a file a row: its key (unique), store, owner, name, type, size, checksum, width, height, metadata, analysis, processing_error and timestamps, with a UUID for its id. The same file of the same owner is one row (a unique index of the owner and the checksum).
• storehouse_usages - which records use each file: the blob, the record's table and id. A blob a record uses cannot be deleted, by the database's own foreign key.

Apps that keep their files in records' columns (Storehouse.Ecto.File) need neither.

Options

• :blobs and :usages - the tables' names. The defaults are "storehouse_blobs" and "storehouse_usages".
• :unique_checksum - false lets an owner keep the same file twice. The default is true.
• :prefix - the database schema (PostgreSQL's) of the tables.