Left Join taking more time

[amit_saini]

Hi Folks ,

I'm using below script , data is huge no doubt but is there any way that instead of Left Join we can use some other logic to solve the purpose.

Color indicates keys here.

CAQ:

LOAD Facility_Id,

     Product,

     Variant,

     Station,

     Serial,

     Characteristic,

     Values,

     Status,

     DTTSERF

FROM

[$(vDataPath)CAQ.qvd]

(qvd);

Left Join (CAQ)

LOAD Station_Id,

     Facility_Id,

     Station_CAQ as Station,

     Station_Name

FROM

[....\Station.qvd]

(qvd);

Left Join (CAQ)

LOAD

     Global_station_Id,

     Station_Id

FROM

[.....\Sub_Station.qvd]

(qvd);

Left Join (CAQ)

LOAD Station_Id as Global_station_Id,

     LineSection,

     Technology,

     Facility_Id,

     Station_Label,

     Line_Id,

     Supplier_Name

FROM

......

Any Suggestions?

Regards,

AS

[arvind_patil]

Hi Amit,

I think there is something wrong in script:

CAQ:

LOAD Facility_Id,

     Product,

     Variant,

     Station,

     Serial,

     Characteristic,

     Values,

     Status,

     DTTSERF

FROM

[$(vDataPath)CAQ.qvd]

(qvd);

Left Join (CAQ)

LOAD Station_Id,

     Facility_Id,

     Station_CAQ as Station,

     Station_Name

FROM

[....\Station.qvd]

(qvd);

Left Join (CAQ)

LOAD

     Global_station_Id,

     Station_Id

FROM

[.....\Sub_Station.qvd]

(qvd);

Left Join (CAQ)

LOAD Station_Id as Global_station_Id,

     LineSection,

     Technology,

     Facility_Id,

     Station_Label,

     Line_Id,

     Supplier_Name

FROM

......

I think  as underline part It may confuse where to join. may be you need to use composite key.

Station_Id &'_'&Facility_Id as KEY1%

Regards,

Arvind Patil

[marcus_sommer]

In my experience is mapping often significantly faster as joining. Therefore Mapping as an Alternative to Joining.

- Marcus