Optimized qvd means it doesn't contain any filtering conditions, and in non ptimized qvd load you can use any filtering conditions like where, groupby etc..
There is no concept of Optimized and Non Optimized QVDs. There is only Optimized and Non Optiminzed QVD loading. There are no functions to make optimized qvd loading, if you are doing any transformations or filtering then it is not optimized QVD loading, but still it is faster than loading from database.
For example:
DATA:
LOAD
*
FROM DataSource; -- Is an optimized load, since we are not doing any transformations
DATA:
LOAD
*,
Field1 * Field2 AS NewField
FROM DataSource; -- This is not an optimized load, since we are deriving a new field from existing fields
Refer Robs post above for Optimized and Non Optimized loading scenarios.
Please find below explanation from Qlikview help file.
A QVD (QlikView Data) file is a file containing a table of data exported from QlikView. QVD is a native QlikView format and can only be written to and read by QlikView. The file format is optimized for speed when reading data from a QlikView script but it is still very compact. Reading data from a QVD file is typically 10-100 times faster than reading from other data sources.
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.
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