6. Impalaアーキテクチャ
● 例: Join(結合)とAggregation(集計)のクエリ
SELECT state, SUM(revenue)
FROM HdfsTbl h JOIN HbaseTbl b ON (...)
GROUP BY 1 ORDER BY 2 desc LIMIT 10
TopN
Agg
TopN
Agg Hash
Agg Join
Hash
Join Hdfs Hbase
Exch Exch
Scan Scan
Hdfs Hbase at coordinator at DataNodes at region servers
Scan Scan