Oracle Database need not verify thata cursor is in the cache because it cannot be deallocated while an applicationcursor associated with it is open.
FETCH emp_cursor BULK COLLECT INTO emp_array LIMIT &rows; FOR i IN 1..emp_array.COUNT LOOP dbms_output.put_line('姓名:'||emp_array(i).ename ||',工资:'||emp_array(i).sal); END LOOP; EXIT WHEN emp_cursor%NOTFOUND; END LOOP; CLOSE emp_cursor; END; / --- 15-14:使用cursor表...
When Oracle Database executes a SQL statement, it stores the result set and processing information in an unnamedprivate SQL area. A pointer to this unnamed area, called acursor, lets youretrieve the rows of the result set one at a time.Cursor attributesreturn information about the state of t...
COUNT(*)ASSTAFFFROMemp_plGROUPBYdeptno)t2WHEREt1.deptno=t2.deptnoANDt2.staff>1;...
CURSOR—Oracle 游标 (cursor)知识 Library cache:主要作用是缓存刚刚执行过的sql语句和PL/SQL语句(如存储过程、函数、包、触发器)锁对应的执行计划、解析树、Pcode/Mcode等对象,当同样的SQL语句和PL/SQL语句再次被执行时,就可以例如已缓存再Library Cache中的那些相关对象而无需再次从头开始解析,这样就提高了这些...
to the mutex then only one session can actually increment (or decrement) the reference count at a time.A wait on "cursor: pin S" thus occurs if a session cannot make that atomic change immediately due to other concurrent requests.Mutexes are local to the current instance in RAC environments...
COUNT(*) --- 108 1、open_cursors与session_cached_cursor的作用open_cursors设定每个session(会话)最多能同时打开多少个cursor(游标)。session_cached_cursor 设定每个session(会话)最多可以缓存多少个关闭掉的cursor。想要弄清楚他们的作用,我们得先弄清楚oracle如何执行每个sql语句。看完上图后...
BrokenCount=1 RevocablePointer=1 KeepDependency=2 Version=0 BucketInUse=1 HandleInUse=1 HandleReferenceCount=0 Concurrency: DependencyMutex=0xcf2e9af8(0, 2, 0, 0) Mutex=0xcf2e9b98(768, 37, 0, 6) Flags=RON/PIN/TIM/PN0/DBN/[10012841] Flags2=[0000] WaitersLists: ...
oracle游标cursor简单使用 总共介绍两种游标一种高效使用游标cursor、sys_refcursor、bulk collect 1、cursor游标使用 /*简单cursor游标 *students表里面有name字段,你可以换做其他表测试 */ --定义 declare --定义游标并且赋值(is 不能和cursor分开使用) cursor stus_cur is select * from students;...
Return a count of the number of data items for the key to which the cursor refers. OperationStatus delete() Delete the key/data pair to which the cursor refers. Cursor dup(boolean samePosition) Creates a new cursor that uses the same transaction and locker ID as the original cursor. ...