On Mon, Feb 13, 2012 at 6:00 PM, hongqizh <[email protected]> wrote: > Thanks for your quick response. In my case, the tables comes from customers > so I can't modify those tables, and some of the tables are very large(for > example, one is more than 600MB) , when I scanning all the data of the > table, the program just does not respond.
Why not? It stops at a particular region? Can you figure which one. Is it not deployed anywhere? Grep its name in master logs to see if you can figure what happened to it? > Do you have a suggestion about > this kind of case? And I think more and more people will encounter this > problem, is that possible in future to add the API to get all the column > names of a column family(such as HColumnDescriptor.getColumnNames() )? > I don't think we'll be adding such a call; it would imply a full scan of the whole table to find every unique column of which there could be millions. If the table is big, it'd need to mapreduce for the result to come back in any reasonable amount of time. St.Ack
