I did not delete anything. I'm not familiar enough with BitCoin-QT files (yet) to know what is appropriate to delete.
If the reindex fails, you should delete the highest numbered blk*.dat and rev*.dat files in the blocks/ folder in the datadir.
Ah. Thank you. If simple "-reindex" fails, then I will delete the content that you describe. Good to know.
I think maybe for small users like me, with no understanding of application internals, BitCoin-QT application may not be sustainable.
This rarely happens and is usually not Bitcoin Core's fault. In many cases, it is just spurious/random corruption (cosmic rays, random bit flipping, etc.). Other times it is a hardware problem.
I have no blame for the software or for the developers. Crypto-coin applications are non-trivial. That being said, non-recoverable errors appear to be increasing in frequency, out in the world. (This is my gut feel. I have no hard data.) Blockchain is 150 GBytes now, approx. Grows daily. 5 Megabit FIOS connection will download new blockchain in 2-3 days, if I am lucky. Reindex also appears to take a long time. I don't know exact duration, yet. If reindex takes 1-2 days to run, but has a high chance of failure, then the most reliable recovery process is to always download a new blockchain. Maybe dedicate a netbook or laptop...keep hot spare blockchain ready at all times. Alternately, I can quit use of personal wallet, and rely upon exchanges. This solution (no personal wallet) is not happy for me. If my crypto-coins are always on deposit in an exchange or coin-bank, and I must use traditional processes to buy/sell, then I might as well simply stay with fiat. Wallets exist that do not require a complete blockchain...but at some level these depend upon existence of a trustworthy blockchain at some third-party entity. Seems as though exchanges are starting to fulfill this need. Not much different from central bank for fiat, in the long run.