I ran into a “There was a problem with reindexing process” with my recently upgraded Magento Community installation. This went from 1.6 to 1.7 and after digging in the command being run, “MAGE_ROOT/shell/indexer.php –reindex catalog_product_price”, I get some nice PDOException errors with a “Base table or view not found” message. It’s informative because it tells me that my catalog_product_index_group_price doesn’t exist.

Further digging resulted in finding this gem: http://www.magereverse.com/. Here you can find all the SQL structure commands used to create the different versions of the software.

So then it is just a matter of running the indexer, looking at the error, and fixing the table in question. These were the tables I had to recreate:

catalog_product_index_price_idx
catalog_product_index_price_opt_idx
catalog_product_index_price_opt_agr_idx
catalog_product_index_price_cfg_opt_agr_idx
catalog_product_index_price_cfg_opt_idx

At this point I took the hint and recreated all the tables that started with catalog_product_index_price_. That fixed the issue for me so hopefully it will for you.