I think I'm looking at the same problem with HBase as Dingding Ye. I need to be able to retrieve a list of rows sorted by data in a column and I'm not sure how to go about it without resorting to performing the sort on the client which feels like I'm just giving up.
My current thinking is to create a map class that outputs key/value pairs where the key is the field I want to sort upon and the value is row key. This way I will get nice sorted input going into my reduce class. I guess I would have to have once reduce class instance. However, I am unclear how I can return the row keys and the families with their column data to the client from the reduce class. All the examples I have found so far write the results to files/tables whereas I want to return objects to a client. In the Hadoop Javadocs I notice a bunch of Comparators but as yet I've not figure out their purpose. If I spend the cycles understanding the purpose of these Comparators are they likely to be of help to me in formulating an alternate/better approach to that described above? -- View this message in context: http://www.nabble.com/Possible-to-set-the-results%27-sort-method--tp20047852p25376341.html Sent from the HBase User mailing list archive at Nabble.com.
