Reason of why OLAP in HBase is possible
OLAP directly upon most of the noSQL databases is not possible, but from what I researched it's actually possible in HBase, so I was wondering what features does HBase have in particular that distinguishes it from the others allowing us to do this.
You will have to write lots of data processing logic in your application layer to accomplish this. Hbase is a Data store not a DBMS. So yes as long as the data goes in, you can get it out and process it in your application layer however you want.
If this proves inconvenient for you and a nosql platform that supports SQL for OLAP is desirable, you could try Amisa Server