Hi, thanks a lot for all response.
Otis: filter from your link are great, i'll check it in my tests. Michael: i understand what is secondary indexes, but still don't have idea about effective rowkey format. I'm ok with delay in creating secondary index and atomicity, we don't need "realitime" data. When i have 10 messages with ids 1, 8, 10, 255, ... from one user with id 88. I see here only 2 options for rowkey in sec. index: 1) composite rowkey like <userId><SEPARATOR><messageId> 2) use userId as rowkey and put messageId into cells Exists any other? When i use first method, i must scan over many rows. What about startRow for scanner? Can be this scan effective? Second method need many many cells and i don't need all in one time, so this is imho bad idea. -- Save The World - http://www.worldcommunitygrid.org/ http://www.worldcommunitygrid.org/stat/viewMemberInfo.do?userName=LesTR Lukas Drbal
