On 8/18/12 12:33 PM, "Stack" <[email protected]> wrote:
>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. Can you be more specific on this? Are you talking about https://issues.apache.org/jira/browse/HBASE-4218 So this is only available in 0.94 then? Thanks. > >> 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
