yongtaoliao created HIVE-25293:
----------------------------------
Summary: Alter partitioned table with "cascade" option create too
many columns records.
Key: HIVE-25293
URL: https://issues.apache.org/jira/browse/HIVE-25293
Project: Hive
Issue Type: Improvement
Components: Metastore
Affects Versions: 3.1.2, 2.3.3
Reporter: yongtaoliao
Assignee: yongtaoliao
When alter partitioned table with "cascade" option, all partitions supports to
be updated. Currently, a CD_ID will be created for each partition, associated
with a set of Columns, which will cause a large amount of redundant data in the
metadata database.
The following DDL statements can reproduce this scenario：
{code:java}
create table test_table (f1 int) partitioned by (p string);
alter table test_table add partition(p='a');
alter table test_table add partition(p='b');
alter table test_table add partition(p='c');
alter table test_table add columns (f2 int) cascade;{code}
All partitions use the table's `CD_ID` before adding columns, while each
partition use their own `CD_ID` after adding columns.
My proposal is all partitions should use the same `CD_ID` when table was
altered with "cascade" option.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
