topic Re: Fact tables in QlikView

Fact tables

Anonymous — Fri, 02 Jan 2015 07:57:54 GMT

Hi All,

how many fact tables can be there in both snow flake and star schema ?

Re: Fact tables

Fri, 02 Jan 2015 08:11:37 GMT

Depends, normally there will be only one fact table in both the schemas but the way the dimensions connect to facts differs.

In mutiple facts situation, they make the normalized table into denormalized table which will become one single fact and which ideally serves the purpose.

Re: Fact tables

Fri, 02 Jan 2015 08:19:49 GMT

Hi it is depends up on ur data , i mean what data ur tacking from the back end and ur requirement ...

normally we have one fact table , in some situation we might have 2 fact tables , in that kind of senior's we have to do combine the 2 facts tables in to 1 or we can maintain 2 fact tables by using link table concept

Re: Fact tables

jagan — Fri, 02 Jan 2015 08:26:11 GMT

Hi,

It depends on your database, there is no restriction. You can have one or multiple fact tables.

Check this link

http://community.qlik.com/message/542932#542932

Regards,

Jagan.

Re: Fact tables

its_anandrjs — Fri, 02 Jan 2015 08:30:59 GMT

Hi,

In Star schema there is only single Fact table where as in the Snow Flake Schema multiple Facts are there but it all depends on your requirements and source data structure. Check this image document.

Hope this helps

Regards

Anand

Re: Fact tables

engishfaque — Fri, 02 Jan 2015 10:25:47 GMT

Dear RGV,

Star Schema: Mostly consist on single fact table and remaining dimension tables are connected with it.

Snow Flow Schema: Mostly consist on more than one fact table and each fact have their own dimension tables.

Kind regards,

Ishfaque Ahmed

Re: Fact tables

SunilChauhan — Fri, 02 Jan 2015 11:12:36 GMT

Both cases single i have seen single fact table generally

but more than one dimensions table in snowflake

its again depend upon your requirement

multiple fact are combined using Concatenate into single table to form star schema and snowflake

if you have more than one fact and smaller data sets using linkage table in star schema and larger can be combined using Concatenate

support we have two fact and linked using linkgae table and different dimesions connected to them then it also forms a star and at same case if you have dimensions connected to dimension it forms snowflake.but there should be performance problem compare to star..

hope this make sense

Re: Fact tables

rajeshvaswani77 — Fri, 02 Jan 2015 12:02:49 GMT

Hi,

You can have more than 1 fact, finally you have to concatenate them to single fact OR create a link table that connects these facts.

thanks,

Rajesh Vaswani