Improve migrations for maven packages feature

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

db/schema.rb

@@ -1922,23 +1922,22 @@ ActiveRecord::Schema.define(version: 20180810155213) do
   end
 
   create_table "packages_maven_metadata", id: :bigserial, force: :cascade do |t|
-    t.integer "package_id", limit: 8, null: false
     t.datetime_with_timezone "created_at", null: false
     t.datetime_with_timezone "updated_at", null: false
+    t.integer "package_id", limit: 8, null: false
     t.string "app_group", null: false
     t.string "app_name", null: false
     t.string "app_version"
     t.text "path", null: false
   end
 
-  add_index "packages_maven_metadata", ["package_id"], name: "index_packages_maven_metadata_on_package_id", using: :btree
-  add_index "packages_maven_metadata", ["path"], name: "index_packages_maven_metadata_on_path", using: :btree
+  add_index "packages_maven_metadata", ["package_id", "path"], name: "index_packages_maven_metadata_on_package_id_and_path", using: :btree
 
   create_table "packages_package_files", id: :bigserial, force: :cascade do |t|
-    t.integer "package_id", limit: 8, null: false
     t.datetime_with_timezone "created_at", null: false
     t.datetime_with_timezone "updated_at", null: false
     t.integer "size", limit: 8
+    t.integer "package_id", limit: 8, null: false
     t.integer "file_type"
     t.integer "file_store"
     t.binary "file_md5"
@@ -1948,12 +1947,11 @@ ActiveRecord::Schema.define(version: 20180810155213) do
   end
 
   add_index "packages_package_files", ["package_id", "file_name"], name: "index_packages_package_files_on_package_id_and_file_name", using: :btree
-  add_index "packages_package_files", ["package_id"], name: "index_packages_package_files_on_package_id", using: :btree
 
   create_table "packages_packages", id: :bigserial, force: :cascade do |t|
-    t.integer "project_id", null: false
     t.datetime_with_timezone "created_at", null: false
     t.datetime_with_timezone "updated_at", null: false
+    t.integer "project_id", null: false
     t.string "name", null: false
     t.string "version"
   end

ee/db/migrate/20180720120726_create_packages_package_files.rb

@@ -8,7 +8,7 @@ class CreatePackagesPackageFiles < ActiveRecord::Migration
 
   def up
     create_table :packages_package_files, id: :bigserial do |t|
-      t.references :package, type: :bigint, index: true, null: false
+      t.references :package, type: :bigint, null: false
 
       t.timestamps_with_timezone null: false
 

ee/db/migrate/20180720121404_create_packages_maven_metadata.rb

@@ -8,15 +8,14 @@ class CreatePackagesMavenMetadata < ActiveRecord::Migration
 
   def up
     create_table :packages_maven_metadata, id: :bigserial do |t|
-      t.references :package, type: :bigint, index: true, null: false
+      t.references :package, type: :bigint, null: false
 
       t.timestamps_with_timezone null: false
 
       t.string :app_group, null: false
       t.string :app_name, null: false
       t.string :app_version
-
-      t.text :path, null: false
+      t.string :path, limit: 1024, null: false
     end
 
     add_concurrent_foreign_key :packages_maven_metadata, :packages_packages,

ee/db/migrate/20180810155213_add_more_indices_to_packages.rb

@@ -7,17 +7,11 @@ class AddMoreIndicesToPackages < ActiveRecord::Migration
 
   def up
     add_concurrent_index :packages_package_files, [:package_id, :file_name]
-    add_concurrent_index :packages_maven_metadata, :path, length: text_index_length
+    add_concurrent_index :packages_maven_metadata, [:package_id, :path]
   end
 
   def down
     remove_concurrent_index :packages_package_files, [:package_id, :file_name]
-    remove_concurrent_index :packages_maven_metadata, :path, length: text_index_length
-  end
-
-  private
-
-  def text_index_length
-    Gitlab::Database.mysql? ? 20 : nil
+    remove_concurrent_index :packages_maven_metadata, [:package_id, :path]
   end
 end