[HIVE-14601] Altering table/partition file format with preexisting data should not be allowed

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Not A Bug
• Component/s: Metastore
• Assignee: Barna Zsombor Klara
• Reporter: Barna Zsombor Klara
• Created: 22/Aug/16 21:16
• Updated: 24/Aug/16 16:40
• Resolved: 24/Aug/16 16:40

Description

The file format of a table or a partition can be changed using an alter statement. However this only affects the metadata, the data in hdfs is not changed, leading to a table from which you cannot select anymore.
Changing the file format back fixes the issue, but a better approach would be to prevent the alter to the file format if we have data in the tables.

The issue is reproducible by executing the following commands:

create table test (id int);
insert into test values (1);
alter table test set fileformat parquet;
insert into test values (2);
select * from test;

Will result in:

java.lang.RuntimeException: .../000000_0 is not a Parquet file (too small) (state=,code=0)