<ruby id="bdb3f"></ruby>

    <p id="bdb3f"><cite id="bdb3f"></cite></p>

      <p id="bdb3f"><cite id="bdb3f"><th id="bdb3f"></th></cite></p><p id="bdb3f"></p>
        <p id="bdb3f"><cite id="bdb3f"></cite></p>

          <pre id="bdb3f"></pre>
          <pre id="bdb3f"><del id="bdb3f"><thead id="bdb3f"></thead></del></pre>

          <ruby id="bdb3f"><mark id="bdb3f"></mark></ruby><ruby id="bdb3f"></ruby>
          <pre id="bdb3f"><pre id="bdb3f"><mark id="bdb3f"></mark></pre></pre><output id="bdb3f"></output><p id="bdb3f"></p><p id="bdb3f"></p>

          <pre id="bdb3f"><del id="bdb3f"><progress id="bdb3f"></progress></del></pre>

                <ruby id="bdb3f"></ruby>

                ??一站式輕松地調用各大LLM模型接口,支持GPT4、智譜、豆包、星火、月之暗面及文生圖、文生視頻 廣告
                **清空dept表** ```sql 0: jdbc:hive2://hadoop101:10000> truncate table dept; ``` **刪除dept表** ```sql 0: jdbc:hive2://hadoop101:10000> drop table if exists dept; ``` **刪除dept表,刪除后放入trash回收站** ```sql 0: jdbc:hive2://hadoop101:10000> drop table if exists dept purge; ``` 未指定 `purge` 時,當刪除表時,將從元數據存儲中刪除表信息,并像通過`hdfs dfs -rm` 那樣刪除原始數據。在許多情況下,這會導致表數據被移動到用戶主目錄中的 `.Trash/Current` 文件夾中,如: ``` /user/root/.Trash/Current/home/hadoop/hive/warehouse/test1.db ``` 因此,錯誤刪除表的用戶可以通過使用相同的模式重新創建表、重新創建任何必要的分區,然后使用 hdfs命令手動將數據移回原位,從而恢復丟失的數據。 <br/> 此解決方案依賴于底層實現,因此可能隨時間或跨安裝發生更改;<mark>強烈建議用戶不要隨意刪除表。</mark> hadoop回收站trash默認是關閉的,可以在 $hadoop/etc/hadoop/core-site.xml 將回收站開啟。 ```xml <property> <name>fs.trash.interval</name> <value>1440</value> <description>Number of minutes between trash checkpoints. If zero, the trash feature is disabled. </description> </property> ``` **對dept表重命名為new_dept** ```sql alter table dept rename to new_dept; ``` **修改/添加dept表的屬性,如comment屬性** ```sql alter table new_dept set tblproperties('comment'='New name Comment'); ``` **修改列與列的分割符** ```sql alter table new_dept set serdeproperties ('field.delim' = '\t'); ``` **修改表存儲格式** ```sql alter table new_dept set fileformat rcfile; ``` **修改列名** ```sql alter table new_dept change old_column new_column int; ``` **添加列** ```sql alter table new_dept add columns(worker string, addr string); ``` **替換列** ```sql -- 按順序從左往右替換列; -- 替換的列少于原表的列,則將原表多出的列刪除,但數據還在; -- 替換的列多于原表的列,則在后邊追加多出的列; alter table new_dept replace columns(column1 int, column2 string); ```
                  <ruby id="bdb3f"></ruby>

                  <p id="bdb3f"><cite id="bdb3f"></cite></p>

                    <p id="bdb3f"><cite id="bdb3f"><th id="bdb3f"></th></cite></p><p id="bdb3f"></p>
                      <p id="bdb3f"><cite id="bdb3f"></cite></p>

                        <pre id="bdb3f"></pre>
                        <pre id="bdb3f"><del id="bdb3f"><thead id="bdb3f"></thead></del></pre>

                        <ruby id="bdb3f"><mark id="bdb3f"></mark></ruby><ruby id="bdb3f"></ruby>
                        <pre id="bdb3f"><pre id="bdb3f"><mark id="bdb3f"></mark></pre></pre><output id="bdb3f"></output><p id="bdb3f"></p><p id="bdb3f"></p>

                        <pre id="bdb3f"><del id="bdb3f"><progress id="bdb3f"></progress></del></pre>

                              <ruby id="bdb3f"></ruby>

                              哎呀哎呀视频在线观看