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Tag: impala

Combining Aggregate Function with resampling in Impala

I have Table in Hadoop in which I have data for different sensor units with a sampling time ts of 1 mSec. I can resample the data for a single unit with a combination of different aggregate functions using the following query in Impala (Let’s say I want to resample the data for each 5 minute using LAST_VALUE() as aggregate

Impala incompatible return types in case when statement

I am running an Impala query and try to use a case when statement: It complains This however works fine: As the error message indicates, PRTCTN_ALLCTD_VL is of type decimal(38,10). Any advice is appreciated Answer This is a curious problem, one that I would not expect. A case expression returns a single type so all the conditions have to converted

Alternative way to run a query with join

I have the below query: select m.name, m.surname,m.teacher, c.classroom,c.floor from table1 as m inner join table2 as c on (m.name=c.name or m.surname = c.surname); But it takes a lot of time to …

How does Impala Implements GroupBy Extension(CUBE, ROLLUP and GROUPING SETS) In a distributed way?

I’m Learning how to Implement GroupBy Extension(CUBE, ROLLUP and GROUPING SETS), I’ve watched at FE several times, But I still can’t understand how to use grouping_ids to implement GroupBy Extension throught collaboration with BE in a distributed way.How is it to collaborition with ExchangeNode? Is it collaborition with ExchangeNode? Can someone help me with the maze? Answer Impala introduced the

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