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发表于 2016-8-11 09:48:58
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本帖最后由 botang 于 2016-8-11 10:30 编辑
关联子查询,当然非常慢。
解决一:
做个视图,然后用视图和表做连接。
解决二:
SQL> conn / as sysdba
Connected.
SQL> create user u1 identified by oracle ;
User created.
SQL> create user u2 identified by oracle ;
User created.
SQL> grant resource , connect to u1;
Grant succeeded.
SQL> grant resource , connect to u2;
Grant succeeded.
SQL> conn u1/oracle
Connected.
SQL> create table a ( col number ) ;
Table created.
SQL> conn u2/oracle
Connected.
SQL> create table a ( col number ) ;
Table created.
SQL> insert into a values (888) ;
1 row created.
SQL> commit;
- SQL> conn / as sysdba
- Connected.
- SQL> merge /*+ append nologging */ into u1.a ua
- 2 using u2.a ub
- 3 on ( ua.col=ub.col )
- 4 when not matched then insert ( col)
- 5 values (ub.col);
- 1 row merged.
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