topic BUFFER (Incremental) in QlikView

BUFFER (Incremental)

Tue, 29 Sep 2009 03:59:50 GMT

I want to get a quicker load and found the BUFFER (Incremental) prefix in the online help:

"All records loaded at a previous occasion are read from the QVD file whereas the following new records are read from the original source and finally an updated QVD-file is created."

If I understand it right, it should first time load normally and save a QVD-file. And next reload will read from the QVD-file and new records are automatically read from the original source. But for me it doesn't work. Subsequent reloads reads from the QVD-file, but the new records are not read.

Do I misunderstand the help? Or does this work for you?

BUFFER (Incremental)

prieper — Tue, 29 Sep 2009 14:59:11 GMT

Can you post an example? As from the OL-Help incremental-option can only be used for text-files, but then it should work.

Peter

BUFFER (Incremental)

Tue, 29 Sep 2009 18:11:36 GMT

I have inserted an example in a pdf-file.

[View:http://community.qlik.com/cfs-file.ashx/__key/CommunityServer.Discussions.Components.Files/11/0576.QlikView-Script-Printing.pdf:550:0]

BUFFER (Incremental)

Tue, 29 Sep 2009 18:33:50 GMT

Hi Hans,

The incremental approach is bit tricky kere. This is applicable only for sequential sorage (like text files). If you are planning to pull from RDBMS using SQL (where insert/update/delete can happen randomly), you need to apply some extra logic.

1. Get the last updated date (D1) from QVD file.

2. Read records from source where date update is >=D1 and <=current date

3. Concatenate the records from existing QVD where the key field(s) not exist in the source.

Note, your soure should have proper audit of updates to do thsi successfully.

-Arun

BUFFER (Incremental)

Tue, 29 Sep 2009 19:41:35 GMT

Hi Arun,

Oh, I understood from the manual, that QlikView did this itself.

Thank you for the information 🐵 I will try your extra logic.

Re: BUFFER (Incremental)

Mon, 24 Dec 2012 16:34:37 GMT

Please give any document.....

Re: BUFFER (Incremental)

Tue, 25 Dec 2012 05:44:18 GMT

Hello,

Hope these Documents will help you