Using indexes in the right places within relational databases is a great way to speed up queries.
To add a basic index in an Ecto migration, use Ecto.Migration.index\2
:
create index(:users, [:email])
Creating a composite index doesn't require jumping through any hoops; just put the relevant column names in the list:
create index(:posts, [:user_id, :title])
See h Ecto.Migration.index
for more details.