Loading Uncompressed Data

[diwakarnahata]

Hi,

Does loading data in uncompressed format in QlikView improves application performance?

I have a 12 GB uncompressed .qvw file which runs 40-50% faster as compared to the application which is compressed - High.

Is this expected? (Note:  We have used a lot of complex set analysis in the application.)

If yes, then what is the use case to load data in compressed format?

Also, are there any Drawbacks of loading an application uncompressed?

Regards,

Diwakar

[marcus_sommer]

Compression is only useful if you need to save storage-space or if you want to transfer the qvw between storages. In all other cases has the compression of a qvw disadvantages then it takes some time to compress and de-compress the file - you will notice it by opening and saving the file. If the file is loaded within the RAM there is no difference between compression or not - it's like using zipping from files within the filesystem.

- Marcus

[diwakarnahata]

So ideally we should not see any difference in performance of a compressed and an uncompressed file when loaded into the Server?

Also, what is the best practice if storage space is not a constraint but performance is more important?

Regards,

Diwakar

[marcus_sommer]

Yes there should be no difference - RAM consumption is the same. Best practice is to turn compression off.

- Marcus