Avoid unnecessary invalidation on setup:upgrade

Author: fredden

app/code/Magento/Indexer/Setup/Recurring.php

@@ -121,8 +121,14 @@ public function install(SchemaSetupInterface $setup, ModuleContextInterface $con
 
             $indexer = $this->indexerFactory->create()->load($indexerId);
             if ($indexer->isScheduled()) {
-                $indexer->setScheduled(false);
-                $indexer->setScheduled(true);
+                // The purpose of the following two lines is to ensure that any
+                // database triggers are correctly set up for this indexer. We
+                // are calling methods on the view directly because we want to
+                // choose to not drop the changelog tables at this time. This
+                // also intentionally bypasses the $indexer->invalidate() call
+                // within $indexer->setScheduled().
+                $indexer->getView()->unsubscribe(false);
+                $indexer->getView()->subscribe();
             }
         }
     }

lib/internal/Magento/Framework/Mview/View.php

@@ -219,27 +219,25 @@ public function subscribe()
     }
 
     /**
-     * Remove subscriptions
-     *
-     * @return ViewInterface
-     * @throws Exception
+     * @inheritDoc
      */
-    public function unsubscribe()
+    public function unsubscribe(bool $dropTable = true): ViewInterface
     {
         if ($this->getState()->getMode() != View\StateInterface::MODE_DISABLED) {
             // Remove subscriptions
             foreach ($this->getSubscriptions() as $subscriptionConfig) {
                 $this->initSubscriptionInstance($subscriptionConfig)->remove();
             }
 
-            try {
-                // Remove changelog table
-                $this->getChangelog()->drop();
-                // Reset version_id
+            if ($dropTable) {
+                try {
+                    $this->getChangelog()->drop();
+                    // phpcs:ignore Magento2.CodeAnalysis.EmptyBlock.DetectedCatch
+                } catch (ChangelogTableNotExistsException $e) {
+                    // We want the table to not exist, and it doesn't. All done.
+                }
+
                 $this->getState()->setVersionId(0);
-            // phpcs:disable Magento2.CodeAnalysis.EmptyBlock.DetectedCatch
-            } catch (ChangelogTableNotExistsException $e) {
-                // Silently ignore this error
             }
 
             // Update view state

lib/internal/Magento/Framework/Mview/ViewInterface.php

@@ -57,12 +57,13 @@ public function load($viewId);
     public function subscribe();
 
     /**
-     * Remove subscriptions
+     * Remove subscriptions and optionally drop the changelog table
      *
+     * @param bool $dropTable
      * @throws \Exception
      * @return ViewInterface
      */
-    public function unsubscribe();
+    public function unsubscribe(bool $dropTable = true): ViewInterface;
 
     /**
      * Materialize view by IDs in changelog