size of qvd and qvw

[yelin_nyu]

Hi, I am relatively new to qlikview. But i noticed something recently, qvw is smaller and qvd is larger when both of them contain the same type of data. Why? I know qvd is extremely fast, but why it is so much larger? Thanks

[#2 · Accepted solution]

qvw is a compressed file, much like a zip-file.

qvd is optimized for loading data so it's less or no compression. It also starts with an XML-description of the data.

[Jason_Michaelides]

Try zipping up the QVD file - you will see it compresses a lot. As Martin says, it is not compressed at all so it can load faster.

[rwunderlich]

Here's some additional information:

http://qlikviewnotes.blogspot.com/2011/03/qlikview-compression.html

-Rob

[#5]

Actually, when qvw load data source directly, then this data source store in its memory(RAM).

why we make qvd file?

     when qvw load the data source by qvd file, then qvw has capability to compress ( up to 90%) qvd file, then it store      in memory . then by this, using less memory than direct load.

so  this is the reason,

when both of them contain the same type of data. Then qvd is extremely fast,

[nikhilgarg]

hey,

i didn't get what you mean by above statement.

Do you want to say that:

When qvw load data directly from data source then data stored in RAM and when load from qvd then data stored in In Memory. Is it what you wanna say ?