@hive.apache.org"
Subject: Re: TPCDS query degrade with hive-3.1.2 because of wrong estimation
for reducers
Based on the plan, filtered output in map-1 had mis-estimates and also groupby
operators have large misestimates.
This is causing the number of reducers to be estimated as "4&qu
Based on the plan, filtered output in map-1 had mis-estimates and also
groupby operators have large misestimates.
This is causing the number of reducers to be estimated as "4" which is less
for this query. Due to the partition factor of tez, it ends up with 8
reducer slots at runtime for hive 3.x.
