Hi,
This is the content in that thread
Hi,
QVD files can be read in two modes: standard (fast) and optimized (faster). The selected mode is determined automatically by the QlikView script engine. Optimized mode can be utilized only when all loaded fields are read without any transformations (formulas acting upon the fields), though the renaming of fields is allowed. A WHERE clause causing QlikView to unpack the records will also disable the optimized load.
1)F1 as NewField - Renaming allowed, so it is optimized load
Ex:
LOAD
Field1 AS Date,
Field2 AS Sales
FROM DataSource;
2)F1 * 2 as NewField – Transformation is not allowed, so it is non optimized load
Ex:
LOAD
Field1 AS Date,
Field2 AS Sales,
Discount,
Field2 - Discount AS NetSales // This is a transformation
FROM DataSource;
3)1 as NewField – Cannot add a new field, so it is non optimized load
LOAD
Field1 AS Date,
Field2 AS Sales,
1 AS Flag // Adding new field
FROM DataSource;
4)WHERE Exists(F1) – We can use Single Field in Exists(), so it is an Optimized load
LOAD
Field1 AS Date,
Field2 AS Sales
FROM DataSource
WHERE Exists(Field1);
5)where exists(F1, Some Transformation) – We cannot use Multiple Field in Exists(), so it is a non Optimized load
LOAD
FirstName,
LastName,
Sales
FROM DataSource
WHERE Exists(Field1, FirstName& ' ' &LastName);
Hope this helps.
Regards,
Jagan.
.png "Luminary Alumni"){kind=icon}
