preceding load visual diagram

[#1]

Hi, all!

I've read a lot about preceding loads and have done my very own super-low-tech diagram.

Did I get it right? Please ignore the SQL * for the database query. I was just too lazy to write the fields again.

[sunny_talwar · Accepted solution]

Looks right to me.

Best,

S

[#3]

yay! Thanks!

[NickHoff]

You did get it right, but you can also do a preceding load on a preceding load for a better performance increase especially when using mapping tables.  You won't see much of a performance gain if you aren't performing an expression in your load.  Take the following example:

UnitCost_Map:

MAPPING LOAD

ProductID,

UnitCost;

SQL SELECT * FROM Products;

LOAD LineSalesAmount - CostOfGoodsSold AS Margin,

*

;

Order Details:

LOAD

LineSalesAmount - CostOfGoodsSold AS Margin,

*

;

LOAD

Discount,

LineNo,

OrderID,

ProductID,

Quantity,

UnitPrice,

UnitPrice * Quantity * (1 - Discount) AS LineSalesAmount,

applymap('UnitCost_Map', ProductID, 0) * Quantity AS CostOfGoodsSold;

SQL SELECT * FROM 'Order Details';

[Anonymous]

Camilla,

"Thanks" is nice, but you can also mark sunindia's answer as correct, and thus give him some points

You can mark your own answer as correct, but no points will be added.

[#6]

Ah - that's interesting - from my inbox I don't have that option. Thanks for reminding me!!

[#7]

Thanks, Nick - I almost put a note in my original post that I was assuming that there would be additional preceding loads, and that there would be aliases, expressions, etc....I just kept it very simple!