Remove default priority from job schema (#897)

README.md

@@ -430,6 +430,17 @@ a job by assigning a numerical `priority`.
   priority. Within a particular priority jobs are executed in their scheduled
   order.
 
+#### Caveats & Guidelines
+
+The default priority is defined in the jobs table. The least intrusive way to
+change it for all jobs is to change the column default:
+
+```elixir
+alter table("oban_jobs") do
+  modify :priority, :integer, default: 1, from: {:integer, default: 0}
+end
+```
+
 ## Unique Jobs
 
 The unique jobs feature lets you specify constraints to prevent enqueueing

lib/oban/job.ex

@@ -134,7 +134,7 @@ defmodule Oban.Job do
     field :attempt, :integer, default: 0
     field :attempted_by, {:array, :string}
     field :max_attempts, :integer, default: 20
-    field :priority, :integer, default: 0
+    field :priority, :integer
 
     field :attempted_at, :utc_datetime_usec
     field :cancelled_at, :utc_datetime_usec

test/oban/job_test.exs

@@ -128,7 +128,7 @@ defmodule Oban.JobTest do
   end
 
   describe "to_map/1" do
-    @keys_with_defaults ~w(args attempt errors max_attempts meta priority queue state tags)a
+    @keys_with_defaults ~w(args attempt errors max_attempts meta queue state tags)a
 
     defp to_keys(opts) do
       %{}