hive tables with parquet data format reorder columns - hive

Question

We are using hive 1.1.0, have a requirement to reorder columns for one of huge table with 100's of columns for user readability. But when we reorder columns in table its failing with below error.
Alternative to reorder columns is create a view on table.
hive> desc test_parquet;
OK
name string
age int
dept string
salary string
city string
# Partition Information
# col_name data_type comment
city string
Time taken: 0.053 seconds, Fetched: 10 row(s)
hive> ALTER TABLE test_parquet REPLACE COLUMNS (age int,name string, dept string, salary string);
OK
Time taken: 0.451 seconds
hive> desc test_parquet;
OK
age int
name string
dept string
salary string
city string
# Partition Information
# col_name data_type comment
city string
Time taken: 0.051 seconds, Fetched: 10 row(s)
hive> select * from test_parquet;
OK
Failed with exception java.io.IOException:java.lang.UnsupportedOperationException: Cannot inspect org.apache.hadoop.io.IntWritable
Time taken: 0.121 seconds

Answer 1

ALTER TABLE ... REPLACE COLUMNS works on the metadata level (metastore).
The new columns order does not match the actual data.
For parquet you get an exception, for textfile you would get NULL values.
You should go with your alternative solution - using a view.

Answer 2

This post is a bit old, however, I thought it would benefit others if have a similar issue!
You can try the below change column method that wors:
ALTER TABLE test_parquet CHANGE COLUMN age age int FIRST; which moves the column to first otherwise, if you want to re order after certain column, below would help:
ALTER TABLE test_parquet CHANGE COLUMN name name string AFTER age;