表结构变化

改变字段长度：

ALTER table schema.table_name ALTER column_name set data type VARCHAR(10);

call sysproc.admin_cmd('reorg table schema.table_name ');
call sysproc.admin_cmd('runstats on table schema.table_name with distribution and indexes all');

增加字段：

ALTER TABLE schema.table_name
ADD COLUMN column_name VARCHAR(100) NOT NULL WITH DEFAULT '*';

加注释：
COMMENT ON COLUMN TM_SEAT_ETERM_AUTHORITY.AGENT_AIRLINE
IS '代理航司';