02-11-2019 12:46 PM
I was looking at this BLOG https://blog.cloudera.com/blog/2017/12/faster-performance-for-selective-queries/
where we see that using "SORT BY" during table creation we can improve impala query performance .
As mentioned in the blog this works only if we use "INSERT" or "CREAT table with select " . Our use case is we create parquet file externally and UPLOAD it onto HDFS and then use IMPALA " LOAD DATA" command. Is there a way we can use "SORT BY" mechanism with this model of loading parquet files.
02-12-2019 08:21 AM
The external tool that you are using would have to support ordering the data by those columns. E.g. if you're using hive, it supports SORT BY. If you're writing it from some custom code, that code would need to sort the data before writing it to parquet.
02-12-2019 09:38 AM
I am using parquet-cpp to write parquet file and the upload it to HDFS using web-hdfs . At the end use "LOAD DATA" command to load iparquet file nto into impla.
Is there any option in parquet-cpp to sort it out.
02-12-2019 10:36 AM
I'm not sure that parquet-cpp has any builtin way to sort data - your client code might have to do the sorting before feeding it to parquet-cpp
02-13-2019 11:47 AM