QVW: Stands for Qlikview Worksheet (The application file which holds your reports/dashboard/script/data model and connection strings)
QVD:
(this is from Help)
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.
A QVD file holds exactly one data table and consists of three parts:
A well formed XML header (in UTF-8 char set) describing the fields in the table, the layout of the subsequent information and some other meta-data.
Symbol tables in a byte stuffed format.
Actual table data in a bit-stuffed format.
Purpose of QVD Files
QVD files can be used for many purposes. At least four major uses can be easily identified. More than one may apply in any given situation:
Increasing Load Speed
By buffering non-changing or slowly changing blocks of input data in QVD files, script execution becomes considerably faster for large data sets.
Decreasing Load on Database Servers
The amount of data fetched from external data sources can also be greatly reduced. This reduces work load on external databases and network traffic. Furthermore, when several QlikView scripts share the same data it is only necessary to load it once from the source database into a QVD file. The other applications can make use of the same data via this QVD file.
QVD.QVW is a QlikView document that does something with QVD's. If you can post the document we can explain what it does. Or just explain where you found it. Your question is sparse on context details.
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