Question

我有一张桌子可以存储大约80辆车的GPS数据。该表每30秒保持GPS传输。我需要删除一些数据，并至少每60秒保持一次GPS转换。所以我有以下过程读取每一行，每个det_id，当当前行距前一行少于59秒时，FLAG列更新为'0'。在此之后，我将删除那些FLAG ='0'的行。

问题是这个程序需要很长时间（300万条记录大约需要40个小时）。我用ts_id和ts_dh做了一个索引，但它没有那么大的变化。

如何改进此程序？我需要做一个特殊的索引吗？我在手术中遗漏了什么吗？

DECLARE

  WriteZero NUMBER:= 0;

    CURSOR CUR_TABLE_SOURCE IS
    SELECT 
           FLAG, ANT_TS_DH,ts_id,TS_DH,TS_DHS
    FROM TABLE_SOURCE
    where ts_id = in_ts_id
    order by ts_id, TS_DH;

    V_count number:=0;  
    V_Ant number:=0;  

    V_TABLESOURCE_REC CUR_TABLE_SOURCE%ROWTYPE;

BEGIN

      OPEN CUR_TABLE_SOURCE;  ---  for update;
      loop
      FETCH CUR_TABLE_SOURCE INTO V_TABLESOURCE_REC;
      EXIT WHEN CUR_TABLE_SOURCE%NOTFOUND;

      V_count := V_count + 1;

      Begin

        IF V_TABLESOURCE_REC.ANT_TS_DH is null then
            UPDATE TABLE_SOURCE SET  
                   FLAG = '1'           
            WHERE ANT_TS_DH = V_TABLESOURCE_REC.ANT_TS_DH
            AND   ts_id = V_TABLESOURCE_REC.ts_id
            AND   TS_DHS = V_TABLESOURCE_REC.TS_DHS;  
            commit;
            V_Ant :=1; 
        ELSE 
                IF V_TABLESOURCE_REC.ANT_TS_DH + 59/86400 >= V_TABLESOURCE_REC.TS_DH THEN 
                        IF V_Ant = 1 THEN
                            UPDATE TABLE_SOURCE SET  
                                   FLAG = '0'  --  delete data with flag = 0
                            WHERE ANT_TS_DH = V_TABLESOURCE_REC.ANT_TS_DH
                            AND   ts_id = V_TABLESOURCE_REC.ts_id
                            AND   TS_DHS = V_TABLESOURCE_REC.TS_DHS;
                            V_Ant :=0; 
                            commit;
                        ELSE
                            UPDATE TABLE_SOURCE SET  
                                    FLAG = '1' --  keep data with flag = 0
                            WHERE ANT_TS_DH = V_TABLESOURCE_REC.ANT_TS_DH
                            AND   ts_id = V_TABLESOURCE_REC.ts_id
                            AND   TS_DHS = V_TABLESOURCE_REC.TS_DHS; 
                            V_Ant :=1; 
                            commit;   
                        End If;       
                ELSE
                    UPDATE TABLE_SOURCE SET  
                           FLAG = '1'
                    WHERE ANT_TS_DH = V_TABLESOURCE_REC.ANT_TS_DH
                    AND   ts_id = V_TABLESOURCE_REC.ts_id
                    AND   TS_DHS = V_TABLESOURCE_REC.TS_DHS; 
                    V_Ant :=1; 
                    commit;   
                End If;     
        End If;  

        End;

  END LOOP;
  CLOSE CUR_TABLE_SOURCE;

 COMMIT;

 END;

这是table_source：

TS_ID TS_DH                 LATI       LONG
----- --------------------- ---------- ----------
 3412 15-DEC-16 11.05.09 AM  11.42341   -81.95251
 3412 15-DEC-16 11.05.39 AM  11.42344   -81.92435
 3412 15-DEC-16 11.06.09 AM  11.43567   -81.85355
 3412 15-DEC-16 11.06.39 AM  11.47851   -81.95246
 3412 15-DEC-16 11.07.10 AM  11.45123   -81.63451
 3412 15-DEC-16 11.07.40 AM  11.43451   -81.95351
 3412 15-DEC-16 11.08.10 AM  11.45251   -81.46785
 3412 15-DEC-16 11.08.40 AM  11.45678   -81.95551
 3412 15-DEC-16 11.09.10 AM  11.43451   -81.93241
 3412 15-DEC-16 11.09.40 AM  11.45456   -81.95251
 3412 15-DEC-16 11.10.10 AM  11.42890   -81.95451
 3412 15-DEC-16 11.15.40 AM  11.43451   -81.95351
 3412 15-DEC-16 11.16.10 AM  11.45251   -81.46785
 3412 15-DEC-16 11.16.40 AM  11.45678   -81.95551
 3412 15-DEC-16 11.17.10 AM  11.43451   -81.93241
 3412 15-DEC-16 11.17.40 AM  11.45456   -81.95251
 3412 15-DEC-16 11.18.10 AM  11.42890   -81.95451

我有一个程序，它需要太长时间，我该怎么办呢？

0 个答案: