Atomic internal ids for all models

3 files changed, 60 insertions, 2 deletions

diff --git a/db/migrate/20180416155103_add_further_scope_columns_to_internal_id_table.rb b/db/migrate/20180416155103_add_further_scope_columns_to_internal_id_table.rb
new file mode 100644
index 00000000000..37e2d19e022
--- /dev/null
+++ b/db/migrate/20180416155103_add_further_scope_columns_to_internal_id_table.rb
@@ -0,0 +1,15 @@
+class AddFurtherScopeColumnsToInternalIdTable < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    change_column_null :internal_ids, :project_id, true
+    add_column :internal_ids, :namespace_id, :integer, null: true
+  end
+
+  def down
+    change_column_null :internal_ids, :project_id, false
+    remove_column :internal_ids, :namespace_id
+  end
+end
diff --git a/db/migrate/20180417090132_add_index_constraints_to_internal_id_table.rb b/db/migrate/20180417090132_add_index_constraints_to_internal_id_table.rb
new file mode 100644
index 00000000000..582b89a3948
--- /dev/null
+++ b/db/migrate/20180417090132_add_index_constraints_to_internal_id_table.rb
@@ -0,0 +1,40 @@
+class AddIndexConstraintsToInternalIdTable < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :internal_ids, [:usage, :namespace_id], unique: true, where: 'namespace_id IS NOT NULL'
+
+    replace_index(:internal_ids, [:usage, :project_id], name: 'index_internal_ids_on_usage_and_project_id') do
+      add_concurrent_index :internal_ids, [:usage, :project_id], unique: true, where: 'project_id IS NOT NULL'
+    end
+
+    add_concurrent_foreign_key :internal_ids, :namespaces, column: :namespace_id, on_delete: :cascade
+  end
+
+  def down
+    remove_concurrent_index :internal_ids, [:usage, :namespace_id]
+
+    replace_index(:internal_ids, [:usage, :project_id], name: 'index_internal_ids_on_usage_and_project_id') do
+      add_concurrent_index :internal_ids, [:usage, :project_id], unique: true
+    end
+
+    remove_foreign_key :internal_ids, column: :namespace_id
+  end
+
+  private
+  def replace_index(table, columns, name:)
+    temporary_name = "#{name}_old"
+
+    if index_exists?(table, columns, name: name)
+      rename_index table, name, temporary_name
+    end
+
+    yield
+
+    remove_concurrent_index_by_name table, temporary_name
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 1d272bdb779..df621956c80 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -896,12 +896,14 @@ ActiveRecord::Schema.define(version: 20180418053107) do
   add_index "identities", ["user_id"], name: "index_identities_on_user_id", using: :btree
 
   create_table "internal_ids", id: :bigserial, force: :cascade do |t|
-    t.integer "project_id", null: false
+    t.integer "project_id"
     t.integer "usage", null: false
     t.integer "last_value", null: false
+    t.integer "namespace_id"
   end
 
-  add_index "internal_ids", ["usage", "project_id"], name: "index_internal_ids_on_usage_and_project_id", unique: true, using: :btree
+  add_index "internal_ids", ["usage", "namespace_id"], name: "index_internal_ids_on_usage_and_namespace_id", unique: true, where: "(namespace_id IS NOT NULL)", using: :btree
+  add_index "internal_ids", ["usage", "project_id"], name: "index_internal_ids_on_usage_and_project_id", unique: true, where: "(project_id IS NOT NULL)", using: :btree
 
   create_table "issue_assignees", id: false, force: :cascade do |t|
     t.integer "user_id", null: false
@@ -2113,6 +2115,7 @@ ActiveRecord::Schema.define(version: 20180418053107) do
   add_foreign_key "gpg_signatures", "gpg_keys", on_delete: :nullify
   add_foreign_key "gpg_signatures", "projects", on_delete: :cascade
   add_foreign_key "group_custom_attributes", "namespaces", column: "group_id", on_delete: :cascade
+  add_foreign_key "internal_ids", "namespaces", name: "fk_162941d509", on_delete: :cascade
   add_foreign_key "internal_ids", "projects", on_delete: :cascade
   add_foreign_key "issue_assignees", "issues", name: "fk_b7d881734a", on_delete: :cascade
   add_foreign_key "issue_assignees", "users", name: "fk_5e0c8d9154", on_delete: :cascade