修改表字段名   先删除旧列，再增加新列 添加字段
具体操作是:alter table [表名] add [new column]
alter table [表名] drop [old column]


alter table gis.TB_NET_ACCUSE_INFO_D add TIME_SEGMENT VARCHAR(50);  -- 新增
alter table gis.TB_NET_ACCUSE_INFO_D drop year;   -- 删除
UPDATE TB_NET_ACCUSE_INFO_M t SET t.TIME_SEGMENT = 'TIM_01' WHERE t.NET_TYPE = 'NET_03';


UPDATE gis.TB_STATION_FLW_TOTAL_M a 
   SET (a.area_code,
        a.subs_area_code,
        a.block_code,
        a.station_desc) =
       (SELECT b.area_code,
               b.subs_area_code,
               b.block_code,
               b.station_desc 
          FROM DW.TB_STATION_NUMBER b 
         WHERE b.STATION_CODE=a.STATION_CODE)

SELECT * FROM TB_2G_NET_INFO_W
alter table gis.TB_2G_NET_INFO_W add year VARCHAR(50);
UPDATE TB_2G_NET_INFO_W t SET t.year = '2012'
UPDATE TB_2G_NET_INFO_W t SET t.spe_01 = NULL 

50.表分区
CREATE TABLE TEST4 (
COL1 INTEGER NOT NULL ,
COL2 BIGINT NOT NULL )
PARTITION BY RANGE 
(COL2 NULLS LAST )
(PARTITION DATAPARTION1 STARTING 
      FROM (1 )INCLUSIVE ENDING 
        AT (10 )INCLUSIVE 
        IN TABLESPACE1 ,
 PARTITION DATAPARTION2 STARTING 
      FROM (11 )INCLUSIVE ENDING 
        AT (20 )INCLUSIVE )
在 schema RHETTE上创建 test4表，含 col1,col2两字段，按 col2进行表分区，DATAPARTION1 存放 col2 1-10
DATAPARTION2 存放 col2 11-20