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Not applicable

Optimized load

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

1 Solution
7 Replies
Not applicable
Author

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

harsh44_bhatia
Creator
Creator

Hello,

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

where exists (<field name>)

or

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;

maxgro
MVP
MVP

rename fields

omit fields

qlikviewwizard
Master II
Master II

qlikviewnovice
Specialist II
Specialist II

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!!

Not applicable
Author

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