diff --git a/activerecord/test/cases/adapters/postgresql/enum_test.rb b/activerecord/test/cases/adapters/postgresql/enum_test.rb
index 47ea79842e..a0559a3a5a 100644
--- a/activerecord/test/cases/adapters/postgresql/enum_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/enum_test.rb
@@ -122,6 +122,8 @@ def test_schema_dump_renamed_enum
   end
 
   def test_schema_dump_added_enum_value
+    skip("Adding enum values can not be run in a transaction") if @connection.database_version < 10_00_00
+
     @connection.add_enum_value :mood, :angry, before: :ok
     @connection.add_enum_value :mood, :nervous, after: :ok
     @connection.add_enum_value :mood, :glad
@@ -132,6 +134,8 @@ def test_schema_dump_added_enum_value
   end
 
   def test_schema_dump_renamed_enum_value
+    skip("Renaming enum values is only supported in PostgreSQL 10 or later") if @connection.database_version < 10_00_00
+
     @connection.rename_enum_value :mood, from: :ok, to: :okay
 
     output = dump_table_schema("postgresql_enums")
diff --git a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
index f70d38aac8..75faae9b7a 100644
--- a/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb
@@ -330,19 +330,21 @@ def test_partial_index_on_column_named_like_keyword
         end
       end
 
-      def test_include_index
-        with_example_table do
-          @connection.add_index "ex", %w{ id }, name: "include", include: :number
-          index = @connection.indexes("ex").find { |idx| idx.name == "include" }
-          assert_equal ["number"], index.include
+      if supports_index_include?
+        def test_include_index
+          with_example_table do
+            @connection.add_index "ex", %w{ id }, name: "include", include: :number
+            index = @connection.indexes("ex").find { |idx| idx.name == "include" }
+            assert_equal ["number"], index.include
+          end
         end
-      end
 
-      def test_include_multiple_columns_index
-        with_example_table do
-          @connection.add_index "ex", %w{ id }, name: "include", include: [:number, :data]
-          index = @connection.indexes("ex").find { |idx| idx.name == "include" }
-          assert_equal ["number", "data"], index.include
+        def test_include_multiple_columns_index
+          with_example_table do
+            @connection.add_index "ex", %w{ id }, name: "include", include: [:number, :data]
+            index = @connection.indexes("ex").find { |idx| idx.name == "include" }
+            assert_equal ["number", "data"], index.include
+          end
         end
       end
 
diff --git a/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb b/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb
index ee48c5b550..7223dd1874 100644
--- a/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/referential_integrity_test.rb
@@ -108,7 +108,7 @@ def test_all_foreign_keys_valid_having_foreign_keys_in_multiple_schemas
       CREATE SCHEMA referential_integrity_test_schema;
 
       CREATE TABLE referential_integrity_test_schema.nodes (
-        id          INT      GENERATED ALWAYS AS IDENTITY,
+        id          BIGSERIAL,
         parent_id   INT      NOT NULL,
         PRIMARY KEY(id),
         CONSTRAINT fk_parent_node FOREIGN KEY(parent_id)
diff --git a/activerecord/test/cases/adapters/postgresql/schema_test.rb b/activerecord/test/cases/adapters/postgresql/schema_test.rb
index e52ee907be..2c94f2aa30 100644
--- a/activerecord/test/cases/adapters/postgresql/schema_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/schema_test.rb
@@ -785,7 +785,7 @@ def test_schema_dumps_index_included_columns
     if ActiveRecord::Base.connection.supports_index_include?
       assert_equal 't.index ["firm_id", "type"], name: "company_include_index", include: ["name", "account_id"]', index_definition
     else
-      assert_equal 't.index ["firm_ids", "type"], name: "company_include_index"', index_definition
+      assert_equal 't.index ["firm_id", "type"], name: "company_include_index"', index_definition
     end
   end
 end
diff --git a/activerecord/test/cases/defaults_test.rb b/activerecord/test/cases/defaults_test.rb
index 8d281a9a44..3a94d5d6b4 100644
--- a/activerecord/test/cases/defaults_test.rb
+++ b/activerecord/test/cases/defaults_test.rb
@@ -152,14 +152,16 @@ class PostgresqlDefaultExpressionTest < ActiveRecord::TestCase
       if ActiveRecord::Base.connection.database_version >= 100000
         assert_match %r/t\.date\s+"modified_date",\s+default: -> { "CURRENT_DATE" }/, output
         assert_match %r/t\.datetime\s+"modified_time",\s+default: -> { "CURRENT_TIMESTAMP" }/, output
+        assert_match %r/t\.datetime\s+"modified_time_without_precision",\s+precision: nil,\s+default: -> { "CURRENT_TIMESTAMP" }/, output
+        assert_match %r/t\.datetime\s+"modified_time_with_precision_0",\s+precision: 0,\s+default: -> { "CURRENT_TIMESTAMP" }/, output
       else
         assert_match %r/t\.date\s+"modified_date",\s+default: -> { "\('now'::text\)::date" }/, output
         assert_match %r/t\.datetime\s+"modified_time",\s+default: -> { "now\(\)" }/, output
+        assert_match %r/t\.datetime\s+"modified_time_without_precision",\s+precision: nil,\s+default: -> { "now\(\)" }/, output
+        assert_match %r/t\.datetime\s+"modified_time_with_precision_0",\s+precision: 0,\s+default: -> { "now\(\)" }/, output
       end
       assert_match %r/t\.date\s+"modified_date_function",\s+default: -> { "now\(\)" }/, output
       assert_match %r/t\.datetime\s+"modified_time_function",\s+default: -> { "now\(\)" }/, output
-      assert_match %r/t\.datetime\s+"modified_time_without_precision",\s+precision: nil,\s+default: -> { "CURRENT_TIMESTAMP" }/, output
-      assert_match %r/t\.datetime\s+"modified_time_with_precision_0",\s+precision: 0,\s+default: -> { "CURRENT_TIMESTAMP" }/, output
     end
   end
 end
diff --git a/activerecord/test/cases/migration/index_test.rb b/activerecord/test/cases/migration/index_test.rb
index 95e262ec98..0b56300612 100644
--- a/activerecord/test/cases/migration/index_test.rb
+++ b/activerecord/test/cases/migration/index_test.rb
@@ -277,6 +277,8 @@ def test_add_partial_index
         end
 
         def test_add_index_with_included_column
+          skip("current adapter doesn't support include indexes") unless supports_index_include?
+
           connection.add_index("testings", "last_name", include: :foo)
           assert connection.index_exists?("testings", "last_name", include: :foo)
 
@@ -285,6 +287,8 @@ def test_add_index_with_included_column
         end
 
         def test_add_index_with_multiple_included_columns
+          skip("current adapter doesn't support include indexes") unless supports_index_include?
+
           connection.add_index("testings", "last_name", include: [:foo, :bar])
           assert connection.index_exists?("testings", "last_name", include: [:foo, :bar])
 
@@ -293,6 +297,8 @@ def test_add_index_with_multiple_included_columns
         end
 
         def test_add_index_with_included_column_and_where_clause
+          skip("current adapter doesn't support include indexes") unless supports_index_include?
+
           connection.add_index("testings", "last_name", include: :foo, where: "first_name = 'john doe'")
           assert connection.index_exists?("testings", "last_name", include: :foo, where: "first_name = 'john doe'")
 
diff --git a/activerecord/test/cases/persistence_test.rb b/activerecord/test/cases/persistence_test.rb
index 5e00aaaa5f..0aa3c0634c 100644
--- a/activerecord/test/cases/persistence_test.rb
+++ b/activerecord/test/cases/persistence_test.rb
@@ -47,7 +47,11 @@ def test_fills_auto_populated_columns_on_creation
     record_with_defaults = Default.create
     assert_not_nil record_with_defaults.id
     assert_equal "Ruby on Rails", record_with_defaults.ruby_on_rails
-    assert_not_nil record_with_defaults.virtual_stored_number if current_adapter?(:PostgreSQLAdapter)
+
+    if current_adapter?(:PostgreSQLAdapter) && ActiveRecord::Base.connection.supports_virtual_columns?
+      assert_not_nil record_with_defaults.virtual_stored_number
+    end
+
     assert_not_nil record_with_defaults.random_number
     assert_not_nil record_with_defaults.modified_date
     assert_not_nil record_with_defaults.modified_date_function
diff --git a/activerecord/test/schema/postgresql_specific_schema.rb b/activerecord/test/schema/postgresql_specific_schema.rb
index 1c78c1125e..611f200c40 100644
--- a/activerecord/test/schema/postgresql_specific_schema.rb
+++ b/activerecord/test/schema/postgresql_specific_schema.rb
@@ -25,7 +25,7 @@
   end
 
   create_table :defaults, force: true do |t|
-    t.virtual :virtual_stored_number, type: :integer, as: "random_number * 10", stored: true
+    t.virtual :virtual_stored_number, type: :integer, as: "random_number * 10", stored: true if supports_virtual_columns?
     t.integer :random_number, default: -> { "random() * 100" }
     t.string :ruby_on_rails, default: -> { "concat('Ruby ', 'on ', 'Rails')" }
     t.date :modified_date, default: -> { "CURRENT_DATE" }
@@ -184,7 +184,5 @@
                                            options: "PARTITION OF measurements FOR VALUES IN (2)")
   end
 
-  if supports_index_include?
-    add_index(:companies, [:firm_id, :type], name: "company_include_index", include: [:name, :account_id])
-  end
+  add_index(:companies, [:firm_id, :type], name: "company_include_index", include: [:name, :account_id])
 end
diff --git a/activerecord/test/support/adapter_helper.rb b/activerecord/test/support/adapter_helper.rb
index a7170949f3..bd14a6e906 100644
--- a/activerecord/test/support/adapter_helper.rb
+++ b/activerecord/test/support/adapter_helper.rb
@@ -49,6 +49,7 @@ def supports_text_column_with_default?
     supports_partial_index?
     supports_partitioned_indexes?
     supports_expression_index?
+    supports_index_include?
     supports_insert_returning?
     supports_insert_on_duplicate_skip?
     supports_insert_on_duplicate_update?