Top "Hadoop-partitioning" questions

Hadoop partitioning deals with questions about how hadoop decides which key/value pairs are to be sent to which reducer (partition).

hadoop map reduce secondary sorting

Can any one explain me how secondary sorting works in hadoop ? Why must one use GroupingComparator and how does it …

hadoop mapreduce hadoop-partitioning
What is the use of grouping comparator in hadoop map reduce

I would like to know why grouping comparator is used in secondary sort of mapreduce. According to the definitive guide …

hadoop mapreduce hadoop-partitioning
HDINSIGHT hive, MSCK REPAIR TABLE table_name throwing error

i have an external partitioned table named employee with partition(year,month,day), everyday a new file come and seat …

hive hadoop-partitioning
In Apache Spark, why does RDD.union not preserve the partitioner?

As everyone knows partitioners in Spark have a huge performance impact on any "wide" operations, so it's usually customized in …

apache-spark partitioning hadoop-partitioning
How the data is split in Hadoop

Does the Hadoop split the data based on the number of mappers set in the program? That is, having a …

hadoop mapreduce hadoop-partitioning
FAILED: ParseException: cannot recognize input near 'exchange' 'string' ',' in column specification

I am using latest AWS Hive version 0.13.0. FAILED: ParseException: cannot recognize input near 'exchange' 'string' ',' in column specification …

hadoop amazon-web-services hive amazon-emr hadoop-partitioning
DELETE FROM table_name Cloudera Impala

I'm new on Impala, and I'm trying to understand how to delete records from a table... I've tried looking for …

hadoop impala hadoop-partitioning
Hadoop - Produce multiple values for a single key

I was able to successfully change the wordcount program in hadoop to suit my requirement. However, I have another situation …

hadoop hadoop-partitioning
Can I cluster by/bucket a table created via "CREATE TABLE AS SELECT....." in Hive?

I am trying to create a table in Hive CREATE TABLE BUCKET_TABLE AS SELECT a.* FROM TABLE1 a LEFT …

hadoop hive hiveql bucket hadoop-partitioning
Hive Partition recovery

How to recover partitions in easy fashion. Here is the scenario : Have 'n' partitions on existing external table 't' Dropped …

hive hdfs hql hadoop-partitioning