mysql游标需要很长时间才能执行

Question

我编写了一个使用游标循环遍历行的过程。执行时间太长。

    CREATE PROCEDURE test_port()
    BEGIN
    declare done BOOL default FALSE;
    declare I,J,C,P,NOB int default 0;
    declare n,k,t int default 0;
    declare Lid int default 0;
    declare inTS timestamp;
    select max(id) into n from MAIN_TBL;
    select ctrValue into k from ID_CNT;
    set k=k+1;
    WHILE k<=n
    do
            select SourcePort,DestPort,LinkID,NoOfBytes,insertTime into I,J,Lid,NOB,inTS from MAIN_TBL where id=k;
            select count(*) into t from APP_PORTMAP_MSTR where Port in (I,J);
            IF(t=1) THEN
                    select Port into P from APP_PORTMAP_MSTR where Port in (I,J);
                    SET C=0;
                    select count(*) INTO C from LINK_APP_TBL where LinkID=Lid and Port=P;
                    insert into TRAFFIC_HIST_TBL(LinkID,Port,NoOfBytes,Time_1) values(Lid,P,NOB,inTS);
                    IF(C=0) THEN
                            insert into LINK_APP_TBL(Port,LinkID) values(P,Lid);
                    END IF;
            ELSE
                    if(I>J && J<>0) THEN
                            SET C=0;
                            select count(*) INTO C from LINK_APP_TBL where LinkID=Lid and Port=J;
                            IF(C=0) THEN
                                    insert into LINK_APP_TBL(Port,LinkID) values(J,Lid);
                                    insert into TRAFFIC_HIST_TBL(LinkID,Port,NoOfBytes,Time_1) values(Lid,J,NOB,inTS);
                            END IF;
                    ELSE
                            SET C=0;
                            select count(*) INTO C from LINK_APP_TBL where LinkID=Lid and Port=I;
      IF(C=0) THEN
                                    insert into LINK_APP_TBL(Port,LinkID) values(I,Lid);
                                    insert into TRAFFIC_HIST_TBL(LinkID,Port,NoOfBytes,Time_1) values(Lid,I,NOB,inTS);
                            END IF;
                    END IF;
            END IF;
    SET k=k+1;
    END WHILE;
    END$$
    \d ;

缓慢的可能原因是“插入”语句，但我们可以通过任何方式提高性能吗？它一次处理大约 10K 条记录。

Answer 1

每秒 10k 是一个很大的数字...您可以尝试删除一些不使用的索引，或者可以将数据文件移动到更快的磁盘(例如 SSD)，这会产生巨大的差异...