Change Index Mode
The Magento 1.x indexer has two settings Update on Save and Manual update. There are several ways to adjust this setting, but the easiest is in the Magento admin. Read the Magento 1 Docs to learn more.
To avoid problems when multiple updates are being performed that trigger automatic reindexing, set all indexers to manual. Otherwise, every time an object is saved, a full reindex will be triggered and any affected objects with dependencies might cause a deadlock. Symptoms of a deadlock include high CPU usage and MySQL errors. As a best practice, schedule indexing as a cron job or run it manually to prevent deadlocks from occurring. Setting indexers to manual is a requirement under our TOS.