Hi Amit, Have you see our documentation and examples for ALTER TABLE [1]?
So you could do ALTER TABLE my_table SET BLOCKCACHE=false; If you want to prevent rows from being put in the block cache on a per query basis, you can use the /*+ NO_CACHE */ hint [2] on a query like this: SELECT /*+ NO_CACHE */ ... Thanks, James [1] https://phoenix.apache.org/language/index.html#alter [2] https://phoenix.apache.org/language/index.html#hint On Fri, Mar 25, 2016 at 6:39 AM, Amit Shah <amits...@gmail.com> wrote: > I noticed that the charts <http://i.imgur.com/ZEJTHWt.png>on cloudera > indicate no block usage when the group by query is executed. This probably > means that the block cache is disabled. The only strange fact is that the > hbase shell describe command gave BLOCKCACHE => 'true'. It would be great > if someone could throw some light on this. > > P.S - Though disabling the block cache didn't speed up the group by query > but that seems like a separate topic of discussion. > > Thanks! > > On Fri, Mar 25, 2016 at 1:34 PM, Amit Shah <amits...@gmail.com> wrote: > >> Hi, >> >> I am using apache hbase (version 1.0.0) and phoenix (version 4.6) >> deployed through cloudera. Since my aggregations with group by query is >> slow, I want to try out disabling the block cache for a particular hbase >> table. I tried a couple of approaches but couldn't succeed. I am verifying >> if the block cache is enabled/disabled through the hbase shell - describe >> 'my_table' command. >> >> 1. Set 'hfile.block.cache.size' property from cloudera console to 0 >> >> 2. alter 'myTable', CONFIGURATION => {NAME => 'myColumnFamily', >> BLOCKCACHE => 'false'} >> >> Even after the above two steps, I get BLOCKCACHE => 'true' in the >> describe command output >> >> COLUMN FAMILIES DESCRIPTION {NAME => '0', DATA_BLOCK_ENCODING => >> 'FAST_DIFF', BLOOMFILTER => 'ROW', REPLICATION_SCOPE => '0', COMPRESSION => >> 'NONE', VERSIONS => '1', MIN_VERSIONS => '0', TTL => 'FOREVER', >> KEEP_DELETED_CELLS => 'FALSE', BLOCKSIZE => '65536', IN_MEMORY => 'false', >> BLOCKCACHE => 'true'} >> >> What could be going wrong? Any suggestions? >> >> Thank you. >> >> >> >
