Stop running indexes of Magento

Sometimes Magento indexes hang up unexpectedly. They are shown as running in Magento backend but looking at the process status (@see https://www.ask-sheldon.com/list-processes-after-cpu-usage/), you recognize that the respective process doesn’t do anything. Other common problems are, that there are payment transactions failures when price index is running (catalog_product_price @see http://magento.stackexchange.com/questions/260/price-re-index-causes-db-deadlocks-during-checkout) or that the search doesn’t work properly, […]