SQL> create table emp1 as select * from emp where 1=2; SQL> insert into emp1 select * from emp; 传统方式数据 SQL> insert /*+ APPEND */ into emp1 select * from emp; 直接方式数据,必须commit后才能查看数据 【实验】直接路径插入数据 SQL>createtableemp1asselect*fromempwhere1=2; SQL>ins...
last_name “Name”, LISTAGG(last_name, ‘; ‘) WITHIN GROUP (ORDER BY hire_date, last_name) OVER (PARTITION BY department_id) as “Emp_list” FROM employees WHERE hire_date < ’01-SEP-2003′ ORDER BY “Dept”, “Date”, “Name”; Dept Date Name Emp_list —–——— 30 07-DEC...
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3.共享SQL语句 为了不重复解析相同的SQL语句,在第一次解析之后, ORACLE将SQL语句存放在内存中.这块位于系统全局区域SGA(system global area)的共享池(shared buffer pool)中的内存可以被所有的数据库用户共享.因此,当你执行一个SQL语句(有时被称为一个游标)时,如果它 和之前的执行过的语句完全相同, ORACLE就能很...
层次化查询,即树型结构查询,是SQL中经常用到的功能之一,通常由根节点,父节点,子节点,叶节点组成,其语法如下: SELECT [LEVEL] ,column,expression,... FROM table_name [WHERE where_clause] [[START WITH start_condition] [CONNECT BY PRIOR prior_condition]]; LEVEL:为伪列,用于表示树的层次 start_condit...
preCopyScript指定每次运行时,复制活动将数据写入到 Oracle 之前要运行的 SQL 查询。 可以使用此属性清除预加载的数据。否 maxConcurrentConnections活动运行期间与数据存储建立的并发连接的上限。 仅在要限制并发连接时指定一个值。无 示例: JSON "activities":[ {"name":"CopyToOracle","type":"Copy","inputs":...
where object_name=upper(‘package1’); 这里需注意upper的使用,数据字典里的所有对象均为大写形式,而PL/SQL里不是大小写敏感的,所以在实际操作中一定要注意大小写匹配。 user_tab_privs视图 该视图主要是存储当前用户下对所有表的权限信息。比如,为了了解当前用户对table1的权限信息,可以执行如下命令: ...
The design of the Event Engine uses a satellite concept, in which there are 1-4 Oracle Fusion Middleware User's Guide for Oracle Business Activity Monitoring Oracle BAM Web Applications four different systems (satellites) which event clauses can be registered with and tracked in. The Date and ...
Que se passe-t-il avecDATEetTIMESTAMP? Cette section concerne les types de donnéessimples. :-) Avant la version 9.2, les pilotes JDBC Oracle mettaient en correspondance le type SQLDATEavecjava.sql.Timestamp.Cela était assez logique, carle type SQL OracleDATEcontient à la fois des informat...
SQL?? HelloDBA.com> alter session set "_optimizer_adaptive_plans"=true; HelloDBA.com> exec sql_explain('select /*+NO_ADAPTIVE_PLAN*/* from t_tab t where table_name = any (select max(object_name) from t_obj o where o.owner=t.owner group by owner)', 'TYPICAL'); Plan hash ...