topic Re: From Relational To QlikView in QlikView

From Relational To QlikView

marco_puccetti — Sat, 18 Jul 2015 11:00:16 GMT

Hello i need some important rules (circulal references etc..) to use generally to import a relational database to a non relational Database like QlikView.

Thanks

Marco

Re: From Relational To QlikView

Anonymous — Sat, 18 Jul 2015 11:11:53 GMT

A star or maybe a snowflake schema is generally recommended for QlikView.

Search for star schema on this forum or the general web and you'll get loads of hits.

Re: From Relational To QlikView

robert_mika — Sat, 18 Jul 2015 11:25:44 GMT

Look here:

https://community.qlik.com/thread/98309‌

last post..

Feeling Qlikngry?

How To /Missing Manual(18 articles)

Re: From Relational To QlikView

maxgro — Sat, 18 Jul 2015 11:44:55 GMT

you have a lot of interesting post to read

Data Modelling: Clarity vs. Speed

and the first links in Marcus_Sommer‌ doc

Get started with developing qlik datamodels

Re: From Relational To QlikView

marco_puccetti — Sat, 18 Jul 2015 13:57:11 GMT

As regards rules to generate a DataWhareHouse model, are there any constrains related to Synthetic keys and intra Synthetic keys elements Generated?

Thanks

Re: From Relational To QlikView

maxgro — Sat, 18 Jul 2015 16:14:09 GMT

First of all, you can find the synthetic keys in any Qlik model that has more than one table (star, snowflake, relational).

IMHO there are no constraints: you can keep your synthetic keys or you can remove the synthetic keys; if the model is correct, it works with the keys and without them.

Personally I usually remove the syn keys and I suggest to people starting with Qlik to remove them: in this way the associations between tables are always set by Qlik developer.

Another reason to remove syn keys is they make harder to understand the Qlik model (using the table viewer), above all when there are a lot of syn keys.

If you have time (a lot of time) read this

Should We Stop Worrying and Love the Synthetic Key?

Re: From Relational To QlikView

marco_puccetti — Wed, 29 Jul 2015 08:59:03 GMT

Hello, i need to know if this model that i have created is considerable star-schema like or some adjustment must be made (the dimensions table can be connected?).

Thanks

Marco

Re: From Relational To QlikView

awhitfield — Wed, 29 Jul 2015 10:01:50 GMT

Hi Marco,

that would be considered a 'snowflake', should be fine

HTH - Andy

Ha - looked a bit closer = STAR SCHEMA!

Re: From Relational To QlikView

avinashelite — Wed, 29 Jul 2015 10:06:43 GMT

Hi Marco,

This model is fine, I feel its a START schema

Re: From Relational To QlikView

marco_puccetti — Wed, 29 Jul 2015 12:11:33 GMT

Notice that the dimension tables are connected.

Marco

Re: From Relational To QlikView

marco_puccetti — Wed, 29 Jul 2015 12:20:52 GMT

Bu isn't this snowflakes?

Re: From Relational To QlikView

awhitfield — Wed, 29 Jul 2015 13:22:56 GMT

No because the main fact table has a direct link to all the outlying tables, it looks like a snowflake only because of the way the table viewer displays the connectors in the image, your is the same as:

HTH - Andy

Re: From Relational To QlikView

maxgro — Wed, 29 Jul 2015 16:33:03 GMT

dimension tables seem only connected to fact table --> star schema

Re: From Relational To QlikView

marco_puccetti — Tue, 04 Aug 2015 11:03:24 GMT

Is it correct for you the following generalization?

The Fact Table must Have a Key for each dimension table.

Marco

Re: From Relational To QlikView

marco_puccetti — Sun, 09 Aug 2015 10:50:50 GMT

Another question if in relational model i have two tables A and B with multeplicity 1..N, in OLAP how can be mapped with star schema with A table as Fact Table?

Generally using join (to add the dimension table key in the fact table) i have, for each row of a dimension table (which is the table with multeplicity N) a row in the fact table, so i ask if the model could be consistent or less.

Thanks

Marco

Re: From Relational To QlikView

maksim_senin — Mon, 10 Aug 2015 04:57:05 GMT

Hi Marco,

If you have two tables only I don't see a reason to build a star-schem model. Moreover for QV it's better to join the two tables into one table due to performans reasons. Maybe I just don't understand your purpose in detail.

Best regards,

Maxim

Re: From Relational To QlikView

marco_puccetti — Mon, 24 Aug 2015 08:39:53 GMT

I don't have only two tables, so i decided to start with a star schema, but if it doesn't work properly due to replicated data in the fact table i need to try with a different method.

So i ask you how to model the relation between two tables, with molteplicity 1..N ?

Thanks

Marco