On Fri, Aug 17, 2012 at 4:42 PM, Gen Liu <[email protected]> wrote: > I assume block cache store compressed data,
Generally its not, not unless you use block encoding. > one block can hold 6 rows, but in random read, maybe 1 row is ever accessed, > 5/6 of the cache space is wasted. > Is there a better way of caching for random read. Lower the block size to 32k > or even 16k might be a choice. > We don't seem to list this as an option in this section, http://hbase.apache.org/book.html#perf.reading, but yes, if lots of random reads, smaller block cache could make a difference. St.Ack
