Ecto.Migration.create_if_not_exists

You're seeing just the function create_if_not_exists, go back to Ecto.Migration module for more information.
Link to this function

create_if_not_exists(index)

View Source

Creates an index or a table with only :id field if one does not yet exist.

Examples

create_if_not_exists index("posts", [:name])

create_if_not_exists table("version")