Sql 提高存储过程的性能

我是一个非db的人。。在改进以下sp示例（如使用全局临时表或索引）时，您是否可以分享您的观点，或者您是否可以改进现有的查询。在原始代码中，我将有许多针对不同表的更新查询。谢谢

CREATE OR REPLACE PROCEDURE SYSTEM.process_log1
IS
    cursor cur_attuid_change is
select
    sup.id as id,
    sup.name as name,
    sup.role as role,
    sup.technology as technology
from main hr, secondary sup
where sup.id=hr.id;

BEGIN
   -- update records in main tables from the cursor
   for rec_attuid_change in cur_attuid_change loop

    update main t1
    set    t1.id    = rec_attuid_change.id,
           t1.name    = rec_attuid_change.name,
           t1.ROLE=rec_attuid_change.role,
           t1.technology=rec_attuid_change.technology
    where  t1.id = rec_attuid_change.id;
    commit;

    update main1 t1
    set    t1.id    = rec_attuid_change.id,
           t1.name    = rec_attuid_change.name,
           t1.ROLE=rec_attuid_change.role,
           t1.technology=rec_attuid_change.technology
    where  t1.id = rec_attuid_change.id;
    commit;

    update main2 t1
    set    t1.id    = rec_attuid_change.id,
           t1.name    = rec_attuid_change.name,
           t1.ROLE=rec_attuid_change.role,
           t1.technology=rec_attuid_change.technology
    where  t1.id = rec_attuid_change.id;
    commit;
   end loop;


END;

/试试这个：

CREATE OR REPLACE PROCEDURE SYSTEM.process_log1

BEGIN

    update main t1
    set (t1.id, t1.name, t1.ROLE, t1.technology ) =
        (select
         sup.id as id,
         sup.name as name,
         sup.role as role,
         sup.technology as technology
         from
         main hr,
         secondary sup
         where
          sup.id=hr.id
          and sup.Id = t1.Id);
    commit;

    update main1 t1
    set (t1.id, t1.name, t1.ROLE, t1.technology ) =
        (select
         sup.id as id,
         sup.name as name,
         sup.role as role,
         sup.technology as technology
         from
         main hr,
         secondary sup
         where
          sup.id=hr.id
          and sup.Id = t1.Id);
    commit;

    update main2 t1
    set (t1.id, t1.name, t1.ROLE, t1.technology ) =
        (select
         sup.id as id,
         sup.name as name,
         sup.role as role,
         sup.technology as technology
         from
         main hr,
         secondary sup
         where
          sup.id=hr.id
          and sup.Id = t1.Id);
    commit;


END;

基本思想是去掉游标，让Oracle运行Set操作（例如，在Venn图中设置，而不是在Set something=中设置）。它将比RAT（一次一排）更快地完成这些任务

我不是100%确定语法，但它来自，大约在页面的三分之一处，您有以下内容：

SET（列名称、列名称……）=（子查询4）

将子查询4从数据库检索到的值分配给列名称列表中的列。子查询必须只返回一行，其中包含列出的所有列。子查询返回的列值按顺序分配给列列表中的列。第一个值分配给列表中的第一列，第二个值分配给列表中的第二列，依此类推