【3】hive中关于partition的操作

hive> create table mp (a string) partitioned by (b string, c string);
OK
Time taken: 0.044 seconds
hive> alter table mp add partition (b='1', c='1');
OK
Time taken: 0.079 seconds
hive> alter table mp add partition (b='1', c='2');
OK
Time taken: 0.052 seconds
hive> alter table mp add partition (b='2', c='2');
OK
Time taken: 0.056 seconds
hive> show partitions mp ;
OK
b=1/c=1
b=1/c=2
b=2/c=2
Time taken: 0.046 seconds
hive> explain extended alter table mp drop partition (b='1');
OK
ABSTRACT SYNTAX TREE:
  (TOK_ALTERTABLE_DROPPARTS mp (TOK_PARTSPEC (TOK_PARTVAL b '1')))

STAGE DEPENDENCIES:
  Stage-0 is a root stage

STAGE PLANS:
  Stage: Stage-0
      Drop Table Operator:
        Drop Table
          table: mp


Time taken: 0.048 seconds
hive> alter table mp drop partition (b='1');
FAILED: Error in metadata: table is partitioned but partition spec is not specified or tab: {b=1}
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask
hive> show partitions mp ;
OK
b=1/c=1
b=1/c=2
b=2/c=2
Time taken: 0.044 seconds
hive> alter table mp add   partition ( b='1', c = '3') partition ( b='1' , c='4');
OK
Time taken: 0.168 seconds
hive> show partitions mp ;
OK
b=1/c=1
b=1/c=2
b=1/c=3
b=1/c=4
b=2/c=2
b=2/c=3
Time taken: 0.066 seconds
hive>insert overwrite table mp partition (b='1', c='1') select cnt from tmp_et3 ;

hive>alter table mp add columns (newcol string);