[impala cache]
https://docs.cloudera.com/documentation/enterprise/6/6.3/topics/impala_perf_hdfs_caching.html
https://docs.cloudera.com/documentation/enterprise/6/properties/6.3/topics/cm_props_cdh630_impala.html
max_result_cache_size 100000
[small files]
https://blog.cloudera.com/the-small-files-problem/
[리밸런싱]
mapreduce locality
block 수 = 작은 파일 많음 = 작은 파일 처리 최적화x
리밸런스하면 해결될수도
[Mapreduce]
https://blog.acronym.co.kr/312
https://m.blog.naver.com/PostView.naver?isHttpsRedirect=true&blogId=alice_k106&logNo=220462251435
