And more usually, you'll use the tool the tool that your most familiar with or can become most familiar [quickest]. You say so yourself, HBase is relatively hard to quickly come to terms. We can observe the same when viewing the "SQL camp" with MySQL and PostgreSQL (and MSSQL).
It is also true of the Facebook HBase install! Completely unnecessary jab; the use of HBase was politically driven -- what the architects wanted to use. What are the proofs that it was the "right tool?" Well, it works, but you won't find it behind Google's Gmail / Talk, so who knows!?
It is also true of the Facebook HBase install! Completely unnecessary jab; the use of HBase was politically driven -- what the architects wanted to use. What are the proofs that it was the "right tool?" Well, it works, but you won't find it behind Google's Gmail / Talk, so who knows!?