这里partition by实现了根据用户名进行分组,order by对结果集根据插入时间进行排序,row_number()函数将每一组的行数单独标注了出来。最后我们取rw=1的数据,也就取到了每个重复用户数据的最新一条数据。 样板数据参考: DROPTABLEIFEXISTS`user_test`;CREATETABLE`user_test` ( `id`int(11)NOTNULLAUTO_INCREMENT, ...
直接用语句删分区就可以了：alter table table_name drop partition partition_name;标准的方式 :select 'alter table '||t.table_owner||'.'||t.table_name||' drop partition ' || t.partition_name || ';'from dba_tab_partitions twhere t.table_name like 'xxxxxx'ORDER BY T.PARTITI...
如果不想REBUIL INDEX,可以用SQL语句手工删除数据,然后再DROP PARTITION. 例子: ALTR ATBEL sales DROP PARTITION dec96; 到底是DROP PARTITION或者是DELETE? 如果GLOBAL INDEX是最重要的,就应该先DELETE 数据再DROP PARTITION。 在下面情况下,手工删除数据的代价比DROP PARTITION要小 - 如果要删除的数据只占整个TABLE...
altertabletransdroppartitiony05q1updateglobalindexes; SQL Download If you decide not to do an automatic index update as part of dropping the partition, that global index will become unusable. You will have to rebuild the index to make it usable, but you can defer that task to later, after ...
--drop_if_exists : Drop the object before creation if it exists. --delete clause : Set the DELETE clause to apply to the Oracle query to be applied before importing data. Can be used multiple time. --oracle_fdw_prefetch: Set the oracle_fdw prefetch value. Larger values generally result...
oracledroppartition能释放空间吗 是的,使用oracledroppartition语句可以释放oracle端存储表分区所占用的空间,前提是oracle表必须有分区概念且分区存在。
THEN'WHERE'||TRIM(T_DATA_FILTER)ELSENULLEND);--判断创建模式--第三步:1、判断表是否存在,如果不存在,创建一个空表先SELECTCOUNT(1)INTOIS_EXISTSFROMALL_TABLES AWHEREA.TABLE_NAME=T_TABLE_NAMEANDA.OWNER=USER;--如果表不存在创建分区表IFIS_EXISTS=0THENifT_CREATE_MODE='003'THENT_PARTITION_NUM ...
alter table 表Aadd new_tempvarchar2(50);update 表Asetnew_temp=a;commit;update 表Aseta='';commit;alter table 表Amodify avarchar2(50);update 表Aseta=new_temp;commit;alter table 表Adrop column new_temp; (3)Oracle表数据回滚语句
[oracle@node3 node3]$ impdp scott/tiger file=number.dmp table_exists_action=append 而使用impdp完成数据库导入时,若表已经存在,有四种的处理方式: 1) skip :默认操作,如果表存在,则跳过 2) replace :先drop表,然后创建表,最后插入数据 3) append :在原来数据的基础上增加数据 ...
If the table exists, Oracle GoldenGate displays the name and the date and time that it was created; otherwise Oracle GoldenGate displays a message stating that the table does not exist. Use the DBLOGIN command to establish a database connection before using this command. table-name The owner...