QVX vs QVD

[#1]

What is the difference between QVX (Qlikview 10) and QVD .

[#2]

Hi,

QVD files can be read and produced only by QlikView, while QVX ones are documented and can be used by custom application, so you can write any application that extract data from anywhere and write QVX that can be load in qv in an optimized way. You can find the documentation in the sdk part of the server installation path.

[korsikov]

QVD : Stands for Qlikview Data (One of the optimize layer of data which has been fetched from the database, qvd is a patent technology of qliktech and qlikview applications reads data 100 time faster as compared to any other sources because data get stores in optimized format. Only Qlikvew application can read the data from QVD. Its always better to fetch the data from from database first and then load the data into your application)

   QVX: Stands for Qlikview Data Exchange (If you wish to make your own connector that could create a connectivity to Qlikview files, One of the efficient and optimize way to fetch data from the database. Mainly used if you are not using ODBC/OLEDB)

[#4]

Alexander, this may seem like a silly question, but can you load QVX into QVD and is it desirable?

eg for a scenario like the following: 

Source  -> Third Party ETL Tool -> QVX ->QVD?

ie if you wish to do a lot of transform work in the third party ETL tool(like Informatica which has a QVX connector)

Or would you now use Informatica to write out to either a target database table(and have Qlik do an ODBC load from the transformed table into a QVD) or even to a delimited file?

eg Source -> Third Party ETL -> <target db>/target file -> QVD

Considering QVDs are much better?

[korsikov]

QVX: A QVX formatted file contains metadata describing a table of data and the actual data. In contrast to the QVD format, which is proprietary and optimized for mininum transformations inside QlikView, the QVX format is public and requires a few transformations when exporting data from traditional data base formats. QVX files are loaded in the script with the load statement. This file type has no configurable settings. QVD: 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.

Advantages: QVX has a well documented internal structure, optimized for streaming data from a database. So if you want to develop a connector of your own, or a piece of software that creates input files for QlikView, you should probably choose QVX. QVD loads faster, but has an internal format which is more complex and has not been published. If you always create your data files using QlikView, you should probably choose QVD.

.

more info you can see here

What is QVX ?

How to create QVX file?

QVD, QVW and QVX