SQL>COMMIT;Commitcomplete. 使用hint 让 sql 语句通过 nested loop 连接, 并且指定 t3 为驱动表 1SQL>select/*+ leading(t3) use_nl(t4)*/*fromt3, t422wheret3.id=t4.t3_idandt3.n=1100;3410rows selected.56SQL>select*fromtable(dbms_xplan.display_cursor(null,null,'allstats last'));78PLAN_TAB...
CURSOR cursor_person is SELECT name FROM person; TYPE person_list IS TABLE of %type; name_list person_list := person_list(); counter integer :=0; BEGIN FOR n IN cursor_person LOOP counter := counter +1; name_list.extend; name_list(counter) := ; dbms_output.put_line(‘Person No....
SYS@vbox66in>select /*+ leading(test1) use_nl(test2) */ test1.*,test2.*2 from test1,test23 where test1.id=test2.t1_id4 and test1.num = 789456123;未选定行 SYS@vbox66in> SYS@vbox66in>select * from table(dbms_xplan.display_cursor(null,null,'allstats last'));PLAN_TABLE_OUTPUT ...
3 where t1.object_id = t2.object_id 4 and t1.object_id in (10, 11, 12); COUNT(*) --- 3 SQL> select * from table(dbms_xplan.display_cursor(null,null,'allstats last')); PLAN_TABLE_OUTPUT --- SQL_ID 0skx6hyjtsncu, child number 0 ---...
dbms_output.put_line(t_customer_names(l_index));ENDLOOP;END;Code language:SQL (Structured Query Language)(sql) Let’s examine the example in detail. First,declare a cursorthat returns the first 10 alphabetically sorted customer names.
Oracle:考虑使用CURSOR_SHARING=FORCE参数 10.3 未来发展趋势 随着硬件发展,Nested Loop Join的一些限制正在被突破: - SSD减少随机IO惩罚 - 内存数据库的兴起 - 向量化执行引擎的优化 - 智能优化器的自动选择能力提升 注:本文示例基于通用SQL语法,具体实现可能因数据库版本不同而有所差异。建议在实际应用中结合EXPLN命...
4 and t1.object_id in (10, 11, 12); COUNT(*) --- 3 SQL> select * from table(dbms_xplan.display_cursor(null,null,'allstats last')); PLAN_TABLE_OUTPUT --- SQL_ID 0skx6hyjtsncu, child number 0 --- select /*+leading(t1) use_nl(t2...
Alternative of CURSOR in SQL to improve performance ? alternative query for in clause Alternative to Full Outer Join Alternative to Row_Number Query Alternative way STUFF for XML PATH ('') ? Am getting an error when i run this code Ambiguous Column Name An aggregate may not appear in th...
CURSOR emp_cur IS SELECT ename FROM emp WHERE ROWNUM <= 10; i INTEGER := 0; BEGIN FOR r_emp IN emp_cur LOOP i := i + 1; emp_arr(i) := r_emp.ename; END LOOP; FOR j IN 1..10 LOOP DBMS_OUTPUT.PUT_LINE(emp_arr(j)); ...
(DBMS) or similar system. The transaction is handled in a coherent and reliable way such that it is independent of the processing of other transactions. The transaction is atomic; it is either entirely completed or aborted. The DBMS will execute the transaction such that the properties of ...