HBASE_CACHING Query Option
      
      Setting this option is equivalent to calling the
        setCaching method of the class org.apache.hadoop.hbase.client.Scan, in an HBase Java
      application. Helps to control the memory pressure on the HBase
      RegionServer, in conjunction with the HBASE_CACHE_BLOCKS
      query option. 
      Type: BOOLEAN
    
Default: 0
Related information:
Using Impala to Query HBase Tables, HBASE_CACHE_BLOCKS Query Option