There seem to be many issues around the re-indexing of product prices on order placement. See the other issue re deadlocks which is related... Price re-index causes DB deadlocks during checkout
I have reported this to Magento and they have replied that I should set indexing to Manual so that it is not run. However I don't see how this is a solution.
In addition to deadlocks, we also notice that some products are suddenly missing from the catalog_product_index_price table after being ordered. They are configurable products and they are in stock, however some of their simple products are not.
The problem is products no longer show up on the website if they don't have a record in product price.
How can I prevent this from happening?
Or why does price have to be reindexed at this time?
I don't think this is needed:
8 /var/www/html/app/code/core/Mage/CatalogInventory/Model/Observer.php(689): Mage_Catalog_Model_Resource_Product_Indexer_Price->reindexProductIds(Array)