topic Re: Optimized load in QlikView

Optimized load

Fri, 28 Aug 2015 14:50:10 GMT

Hello I have a question:

When I load data from a QVD file and use the EXISTS function to filter the data, what is the only other operation I can do while still maintaining an 'Optimized' load?

Thank you

Re: Optimized load

Fri, 28 Aug 2015 14:55:04 GMT

Some examples of things that will cause a non-optimised load are:

– Adding new fields to the table
– Deriving new values from a field in the QVD
– Retrieving a field twice
– Most WHERE conditions
– Joining to an existing in memory table
– Loading data into a mapping table

In contrast the things you are allowed to do are:

– Rename fields
– Omit fields
– Do a simple one field WHERE EXISTS on a field returned in the record set

Re: Optimized load

harsh44_bhatia — Fri, 28 Aug 2015 15:07:55 GMT

Hello,

1. You may rename fields, also make sure you have the following for exists clause.

where exists (<field name>)

where not exists (<field name>)

if you use two field names in the exists clause you will not have optimized load

for eg: where exists (field1,field2);

2. if you are concatenating the tables

Lets say table A have 5 columns(F1,F2,F3,F4,F5) and table B have subset of columns from Table A lets say B(F1,F2,F3)

then you should first load table A followed by Table B

temp:

Load F1,F2,F3,F4,F5

from ....TableA

concatenate(temp)

Load F1,F2,F3

from .... TableB;

Re: Optimized load

chaper — Fri, 28 Aug 2015 15:19:54 GMT

Hope these help you

When less data means more RAM | Qlikview Cookbook

optimize and non-optimze load in qvd

what are optimized loads and unoptimized loads ?

Re: Optimized load

maxgro — Fri, 28 Aug 2015 15:30:43 GMT

rename fields

omit fields

Re: Optimized load

qlikviewwizard — Sat, 29 Aug 2015 02:33:56 GMT

Optimised and Unoptimised qvd.

What is optimised QVD?

Re: Optimized load

Anonymous — Sat, 29 Aug 2015 03:20:16 GMT

Hi,

Refer this:

Re: what are the functions we can use in optimized qvd and non optimized qvd?

Exists with 1 parameter

Rename Fields

Omit Fields

For more details have a look below links:

EXIST while loading QVD

Re: what are functions we are using in optimized qvd ? and non optimized? urgent...

Hope it will help!!

Re: Optimized load

Thu, 22 Dec 2016 07:57:44 GMT

Can you confirm the order of TableA/TableB in your example. I understand that way to guarantee optimized load is to load the smaller Table first (smaller in terms of less fields, I mean). Effectively, you will concatenate the table with more fields to the table with less fields. Also worth noting, the second table must include all the fields of the first table, then add some to maintain the optimization.

This post has a very useful example/explanation of these: Turning Unoptimized Loads into Optimized Loads