hive修改表模式
hive用户可以通过alter语句更改table属性

Alter Partitions
增加partitions：

hive> alter table alter_test add columns(test_columen INT);OKTime taken: 2.096 secondshive> desc alter_test;                                     OKid      intname    stringtest_columen    intdt      stringTime taken: 0.345 secondshive> select * from alter_test;OK3       cds     NULL    2012-08-114       mac     NULL    2012-08-111       zxm     NULL    2012-08-122       ljz     NULL    2012-08-121       zxm     NULL    2012-08-132       ljz     NULL    2012-08-13Time taken: 8.467 secondshive> alter table alter_test replace columns (id int, name string);                  OKTime taken: 0.217 secondshive> desc alter_test;                                             OKid      intname    stringdt      stringTime taken: 0.181 secondshive> select * from alter_test;                                    OK3       cds     2012-08-114       mac     2012-08-111       zxm     2012-08-122       ljz     2012-08-121       zxm     2012-08-132       ljz     2012-08-13Time taken: 0.364 secondshive> alter table alter_test change id myid INT;OKTime taken: 0.259 secondshive> desc alter_test;OKmyid    intname    stringdt      stringTime taken: 0.053 seconds

注意：column alter仅仅修改table的元数据，而不会修改数据。

其它：
hive alter语句还支持：
1.Alter Table Properties
2.Alter SerDe Properties
3.Alter Table/Partition File Format
4.Alter Table Storage Properties
5.Alter Table/Partition Location
6.Alter Table Touch
7.Alter Table (Un)Archive
8.Alter Table/Partition Protections
9.Alter Table Rename Partition

reference:
Hive LanguageManualDDL