1 files changed, 39 insertions, 0 deletions
diff --git a/db/migrate/20210611100359_rebuild_index_for_cadence_iterations_automation.rb b/db/migrate/20210611100359_rebuild_index_for_cadence_iterations_automation.rb
new file mode 100644
index 00000000000..ecd8bac22be
--- /dev/null
+++ b/db/migrate/20210611100359_rebuild_index_for_cadence_iterations_automation.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class RebuildIndexForCadenceIterationsAutomation < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  INDEX_NAME = 'cadence_create_iterations_automation'
+
+  disable_ddl_transaction!
+
+  def up
+    return if index_exists_and_is_valid?
+
+    remove_concurrent_index_by_name :iterations_cadences, INDEX_NAME
+
+    disable_statement_timeout do
+      execute(
+        <<-SQL
+          CREATE INDEX CONCURRENTLY #{INDEX_NAME} ON iterations_cadences
+          USING BTREE(automatic, duration_in_weeks, (DATE ((COALESCE("iterations_cadences"."last_run_date", DATE('01-01-1970')) + "iterations_cadences"."duration_in_weeks" * INTERVAL '1 week')))) 
+          WHERE duration_in_weeks IS NOT NULL
+      SQL
+      )
+    end
+  end
+
+  def down
+    remove_concurrent_index_by_name :iterations_cadences, INDEX_NAME
+  end
+
+  def index_exists_and_is_valid?
+    execute(
+      <<-SQL
+        SELECT identifier
+        FROM postgres_indexes
+        WHERE identifier LIKE '%#{INDEX_NAME}' AND valid_index=TRUE
+      SQL
+    ).any?
+  end
+end