From 5f8831ee843117ac87272be0bf5b1049b077b6b9 Mon Sep 17 00:00:00 2001
From: Michal Gibowski <gibowski@gmail.com>
Date: Wed, 3 Apr 2024 20:31:40 +0100
Subject: [PATCH] WIP

---
 lib/ecto/adapters/postgres/connection.ex |  4 +++-
 lib/ecto/adapters/sql.ex                 |  3 +++
 lib/ecto/migration.ex                    | 15 +++++++++++++--
 lib/ecto/migration/runner.ex             | 18 ++++++++++++++----
 test/ecto/migration_test.exs             | 19 +++++++++++++++++++
 5 files changed, 52 insertions(+), 7 deletions(-)

diff --git a/lib/ecto/adapters/postgres/connection.ex b/lib/ecto/adapters/postgres/connection.ex
index 9b59e7f5..5e1660fd 100644
--- a/lib/ecto/adapters/postgres/connection.ex
+++ b/lib/ecto/adapters/postgres/connection.ex
@@ -1239,7 +1239,9 @@ if Code.ensure_loaded?(Postgrex) do
       table_name = quote_name(table.prefix, table.name)
 
       query = [
-        "CREATE TABLE ",
+        "CREATE ",
+        if_do(table.unlogged, "UNLOGGED "),
+        "TABLE ",
         if_do(command == :create_if_not_exists, "IF NOT EXISTS "),
         table_name,
         ?\s,
diff --git a/lib/ecto/adapters/sql.ex b/lib/ecto/adapters/sql.ex
index ba98643e..3c9c8557 100644
--- a/lib/ecto/adapters/sql.ex
+++ b/lib/ecto/adapters/sql.ex
@@ -871,6 +871,9 @@ defmodule Ecto.Adapters.SQL do
       IO.warn(message)
     end
 
+    # TODO: warn if :create_unlogged_tables and not in tests
+    # TODO: warn if :create_unlogged_tables and adapter other than Postgrex
+
     config
     |> Keyword.delete(:name)
     |> Keyword.update(:pool, DBConnection.ConnectionPool, &normalize_pool/1)
diff --git a/lib/ecto/migration.ex b/lib/ecto/migration.ex
index 7b70dcde..44255320 100644
--- a/lib/ecto/migration.ex
+++ b/lib/ecto/migration.ex
@@ -416,7 +416,13 @@ defmodule Ecto.Migration do
 
     To define a table in a migration, see `Ecto.Migration.table/2`.
     """
-    defstruct name: nil, prefix: nil, comment: nil, primary_key: true, engine: nil, options: nil
+    defstruct name: nil,
+              prefix: nil,
+              comment: nil,
+              primary_key: true,
+              engine: nil,
+              options: nil,
+              unlogged: false
 
     @type t :: %__MODULE__{
             name: String.t(),
@@ -424,7 +430,8 @@ defmodule Ecto.Migration do
             comment: String.t() | nil,
             primary_key: boolean | keyword(),
             engine: atom,
-            options: String.t()
+            options: String.t(),
+            unlogged: boolean
           }
   end
 
@@ -560,6 +567,8 @@ defmodule Ecto.Migration do
   defp expand_create(object, command, block) do
     quote do
       table = %Table{} = unquote(object)
+      unlogged = Runner.repo_config(:create_unlogged_tables, false)
+      table = %Table{table | unlogged: unlogged}
       Runner.start_command({unquote(command), Ecto.Migration.__prefix__(table)})
 
       if primary_key = Ecto.Migration.__primary_key__(table) do
@@ -623,6 +632,8 @@ defmodule Ecto.Migration do
   end
 
   def create(%Table{} = table) do
+    unlogged = Runner.repo_config(:create_unlogged_tables, table.unlogged)
+    table = %Table{table | unlogged: unlogged}
     do_create(table, :create)
     table
   end
diff --git a/lib/ecto/migration/runner.ex b/lib/ecto/migration/runner.ex
index 38170b52..414b5928 100644
--- a/lib/ecto/migration/runner.ex
+++ b/lib/ecto/migration/runner.ex
@@ -432,11 +432,21 @@ defmodule Ecto.Migration.Runner do
   defp command(ddl) when is_binary(ddl) or is_list(ddl),
     do: "execute #{inspect(ddl)}"
 
-  defp command({:create, %Table{} = table, _}),
-    do: "create table #{quote_name(table.prefix, table.name)}"
+  defp command({:create, %Table{} = table, _}) do
+    if repo_config(:create_unlogged_tables, false) do
+      "create unlogged table #{quote_name(table.prefix, table.name)}"
+    else
+      "create table #{quote_name(table.prefix, table.name)}"
+    end
+  end
 
-  defp command({:create_if_not_exists, %Table{} = table, _}),
-    do: "create table if not exists #{quote_name(table.prefix, table.name)}"
+  defp command({:create_if_not_exists, %Table{} = table, _}) do
+    if repo_config(:create_unlogged_tables, false) do
+      "create unlogged table if not exists #{quote_name(table.prefix, table.name)}"
+    else
+      "create table if not exists #{quote_name(table.prefix, table.name)}"
+    end
+  end
 
   defp command({:alter, %Table{} = table, _}),
     do: "alter table #{quote_name(table.prefix, table.name)}"
diff --git a/test/ecto/migration_test.exs b/test/ecto/migration_test.exs
index 1c865185..3f18a99b 100644
--- a/test/ecto/migration_test.exs
+++ b/test/ecto/migration_test.exs
@@ -461,6 +461,16 @@ defmodule Ecto.MigrationTest do
                {:create, table, [{:add, :id, :bigserial, [primary_key: true]}]}
     end
 
+    @tag repo_config: [create_unlogged_tables: true]
+    test "create unlogged table" do
+      create table = table(:posts)
+      flush()
+
+      assert last_command() ==
+               {:create, %Table{table | unlogged: true},
+                [{:add, :id, :bigserial, [primary_key: true]}]}
+    end
+
     test "alters a table" do
       alter table(:posts) do
         add :summary, :text
@@ -721,6 +731,15 @@ defmodule Ecto.MigrationTest do
                    end
     end
 
+    @tag repo_config: [create_unlogged_tables: true]
+    test "creates unlogged table" do
+      create(table(:posts))
+      flush()
+
+      {_, table, _} = last_command()
+      assert table.unlogged == true
+    end
+
     test "drops a table with prefix from migration" do
       drop(table(:posts, prefix: "foo"))
       flush()