Merge branch 'fix-retried-for-mysql' into 'master'

Fixes broken MySQL migration for retried

Closes #32647

See merge request !11593

Conflicts:
	db/post_migrate/20170503004427_upate_retried_for_ci_build.rb

db/post_migrate/20170503004427_upate_retried_for_ci_build.rb

@@ -8,6 +8,7 @@ class UpateRetriedForCiBuild < ActiveRecord::Migration
   def up
     disable_statement_timeout
+<<<<<<< HEAD
     latest_id = <<-SQL.strip_heredoc
       SELECT MAX(ci_builds2.id)
         FROM ci_builds ci_builds2
@@ -25,5 +26,61 @@ class UpateRetriedForCiBuild < ActiveRecord::Migration
   end
   def down
+=======
+    if Gitlab::Database.mysql?
+      up_mysql
+    else
+      up_postgres
+    end
+  end
+
+  def down
+  end
+
+  private
+
+  def up_mysql
+    # This is a trick to overcome MySQL limitation: 
+    # Mysql2::Error: Table 'ci_builds' is specified twice, both as a target for 'UPDATE' and as a separate source for data
+    # However, this leads to create a temporary table from `max(ci_builds.id)` which is slow and do full database update
+    execute <<-SQL.strip_heredoc
+      UPDATE ci_builds SET retried=
+        (id NOT IN (
+          SELECT * FROM (SELECT MAX(ci_builds.id) FROM ci_builds GROUP BY commit_id, name) AS latest_jobs
+        ))
+      WHERE retried IS NULL
+    SQL
+  end
+
+  def up_postgres
+    with_temporary_partial_index do
+      latest_id = <<-SQL.strip_heredoc
+        SELECT MAX(ci_builds2.id)
+          FROM ci_builds ci_builds2
+          WHERE ci_builds.commit_id=ci_builds2.commit_id
+            AND ci_builds.name=ci_builds2.name
+      SQL
+
+      # This is slow update as it does single-row query
+      # This is designed to be run as idle, or a post deployment migration
+      is_retried = Arel.sql("((#{latest_id}) != ci_builds.id)")
+
+      update_column_in_batches(:ci_builds, :retried, is_retried) do |table, query|
+        query.where(table[:retried].eq(nil))
+      end
+    end
+  end
+
+  def with_temporary_partial_index
+    if Gitlab::Database.postgresql?
+      execute 'CREATE INDEX CONCURRENTLY IF NOT EXISTS index_for_ci_builds_retried_migration ON ci_builds (id) WHERE retried IS NULL;'
+    end
+
+    yield
+
+    if Gitlab::Database.postgresql?
+      execute 'DROP INDEX CONCURRENTLY IF EXISTS index_for_ci_builds_retried_migration'
+    end
+>>>>>>> 7f31768... Merge branch 'fix-retried-for-mysql' into 'master'
   end
 end

spec/migrations/upate_retried_for_ci_builds_spec.rb

+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20170503004427_upate_retried_for_ci_build.rb')
+
+describe UpateRetriedForCiBuild, truncate: true do
+  let(:pipeline) { create(:ci_pipeline) }
+  let!(:build_old) { create(:ci_build, pipeline: pipeline, name: 'test') }
+  let!(:build_new) { create(:ci_build, pipeline: pipeline, name: 'test') }
+
+  before do
+    described_class.new.up
+  end
+
+  it 'updates ci_builds.is_retried' do
+    expect(build_old.reload).to be_retried
+    expect(build_new.reload).not_to be_retried
+  end
+end