dremio 建立反射的指令

建立反射

• 原始

ALTER DATASET <DATASET_PATH>       

CREATE RAW REFLECTION <REFLECTION_NAME>       

USING      

DISPLAY (      

field1,      

field2,      

field3      

)      

[PARTITION BY (field1)]      

[LOCALSORT BY (field2)]      

[DISTRIBUTE BY (field2)]      

• 聚合

ALTER TABLE <Source_PDS_OR_VDS_NAME>       

CREATE AGGREGATE REFLECTION <reflection_name>       

USING       

DIMENSIONS (x by day, y)       

MEASURES (b (COUNT, MIN, MAX, SUM, APPROXIMATE COUNT DISTINCT))       

--PARTITION BY (col1,col2...)       

--LOCALSORT BY (col1,col2...)      

--ARROW CACHE      

--DISTRIBUTE BY (col1,col2...)      

• 外部

ALTER DATASET <SOURCE_DATASET_PATH>       

CREATE EXTERNAL REFLECTION <REFLECTION_NAME>       

USING <TARGET_DATASET_PATH>      

删除反射

ALTER DATASET <DATASET_PATH> DROP REFLECTION <REFLECTION_NAME>      

說明

參考資料