Type: New Feature
Affects Version/s: None
Fix Version/s: 0.10.0
Release Note:Set hive-conf hive.fetch.task.conversion to more to make use of this feature. Turned-off by default.
I often find myself needing to take a quick look at a particular column of a Hive table.
I usually do this by doing a
SELECT * from <table> LIMIT 20;
from the CLI. Doing this is pretty fast since it doesn't require a mapreduce job. However, it's tough to examine just 1 or 2 columns when the table is very wide.
So, I might do
SELECT <col> from <table> LIMIT 20;
but it's much slower since it requires a map-reduce. It'd be really convenient if a map-reduce wasn't necessary.
Currently a good work around is to do
hive -e "select * from table" | cut --key=n
but it'd be more convenient if it were built in since it alleviates the need for column counting.