the original magento indexing happened to be so slow  , in my case I had millions of SKUs need to be indexed , converted to flat table & url rewritten .

original magento indexing takes to many days & then it stop 

after digging in the code I saw its very complicated task and usually it delete all the `catalog_product_flat` table causing the site to go offline 


any suggestion to have custom indexer , faster indexer ???

thanks for suggestion