Hyphenate "database specific" [ci-skip]

"database-specific" is a compound adjective, and thus hyphenated.

activerecord/lib/active_record/attribute_methods/dirty.rb

@@ -7,7 +7,7 @@ module AttributeMethods
     # = Active Record Attribute Methods \Dirty
     #
     # Provides a way to track changes in your Active Record models. It adds all
-    # methods from ActiveModel::Dirty and adds database specific methods.
+    # methods from ActiveModel::Dirty and adds database-specific methods.
     #
     # A newly created +Person+ object is unchanged:
     #

activerecord/lib/active_record/timestamp.rb

@@ -30,7 +30,7 @@ module ActiveRecord
   #
   #   ActiveRecord::Base.time_zone_aware_types = [:datetime]
   #
-  # You can also add database specific timezone aware types. For example, for PostgreSQL:
+  # You can also add database-specific timezone aware types. For example, for PostgreSQL:
   #
   #   ActiveRecord::Base.time_zone_aware_types += [:tsrange, :tstzrange]
   #

activerecord/test/cases/arel/select_manager_test.rb

@@ -963,7 +963,7 @@ def test_join_sources
         _(manager.where_sql).must_be_like %{ WHERE "users"."id" = 10 AND "users"."id" = 11}
       end
 
-      it "handles database specific statements" do
+      it "handles database-specific statements" do
         old_visitor = Table.engine.connection.visitor
         Table.engine.connection.visitor = Visitors::PostgreSQL.new Table.engine.connection
         table   = Table.new :users

guides/source/active_record_migrations.md

@@ -374,7 +374,7 @@ you. You can change the name of the column with the `:primary_key` option, or
 pass an array to `:primary_key` for a composite primary key. If you don't want
 a primary key at all, you can pass the option `id: false`.
 
-If you need to pass database specific options you can place an SQL fragment in
+If you need to pass database-specific options you can place an SQL fragment in
 the `:options` option. For example:
 
 ```ruby