topic Re: How many fact tables will be there in star schema? in QlikView

How many fact tables will be there in star schema?

Mon, 27 Oct 2014 11:58:24 GMT

How many fact tables will be there in star schema?if it is more then one how to make them connected.

Re: How many fact tables will be there in star schema?

Mon, 27 Oct 2014 12:04:07 GMT

Hi,

Star schema contains only one fact table.

If you have morethan one fact table then if you are going to imploment star schema then concatinate the fact tables into 1 fact table.

Just like this

load * from fact1;

concatenate

load * from fact2;

concatenate

load * from fact3;

Re: How many fact tables will be there in star schema?

its_anandrjs — Mon, 27 Oct 2014 12:04:49 GMT

There is only one fact table in the Star schema if you have to use more than one then use the link tables in between them which is used as the reference table.

Regards,

Anand

Re: How many fact tables will be there in star schema?

vardhancse — Mon, 27 Oct 2014 12:08:25 GMT

As per Star Schema,,will say only one fact table.

But in real time don't think only one fact table was possible.

We can join multiple fact tables in to single table.

Re: How many fact tables will be there in star schema?

Mon, 27 Oct 2014 12:08:35 GMT

Thank you Anand,

can you please give me any simple example with sample date how two fact tables will be linked and how can we test combination of links while testing data integrity like combination can i get total output data.

Re: How many fact tables will be there in star schema?

Mon, 27 Oct 2014 12:22:43 GMT

Hi Sasi,

i have one query is it posiible to make join bw two facts?if it is can u please give sample example.

Re: How many fact tables will be there in star schema?

vardhancse — Tue, 28 Oct 2014 05:40:43 GMT

Hi,

We can join 2 fact tables.

ABC:

LOAD

From Table_1;

Left join(ABC)

LOAD

From Table_2;

Re: How many fact tables will be there in star schema?

jagan — Tue, 28 Oct 2014 06:24:00 GMT

Hi Venu,

Generally there is one fact table and n dimension tables surrounding it, if you have more than one Fact table, then you can convert to one fact table using concatenate like below

TransactionData:

LOAD

ProductID,

BranchID,

Sales,

'Sales' AS Flag

FROM FactTable1;

Concatenate(TransactionData)

LOAD

ProductID,

BranchID,

Budget,

'Budget' AS Flag

FROM FactTable2;

Product:

LOAD

FROM PRoduct;

Branch:

LOAD

FROM Branch;

Or if both are different data then try to generate the data model like below

Regards,

Jagan.

Re: How many fact tables will be there in star schema?

Tue, 28 Oct 2014 16:05:23 GMT

Hi Jagan

Thank u so much,

can u please give me clarification about flags.'Sales' as flag?????(why this).

Re: How many fact tables will be there in star schema?

jagan — Wed, 29 Oct 2014 01:41:08 GMT

Hi,

Flags are used to identify from which Source table the record belongs to, if you don't have this flag you don't have any clue from which table particular row belongs to, since we are concatenating multiple tables. It is a good practice to arrive a flag in script, latest it would be very useful for troubleshooting if there is any issues.

If you got the answer please close this thread by giving Correct Answer to the useful post.

Regards,

Jagan.

Re: How many fact tables will be there in star schema?

Anonymous — Wed, 29 Oct 2014 03:16:18 GMT

In general we should have one star schema to make avoid many associations.

You can have more than one fact table as Jagan said.

BR/Chinna Katiki

Re: How many fact tables will be there in star schema?

Anonymous — Wed, 29 Oct 2014 03:23:17 GMT

Hey..

It is just to avoid the confusion about what type of fact data you are reading into your UI..it is a best practice to differentiate the fact data if both fact tables are having similar kind of column structure.

Regards,

Chinna

Re: How many fact tables will be there in star schema?

Mon, 24 Nov 2014 17:38:55 GMT

Nice replay

Re: How many fact tables will be there in star schema?

alexandernatale — Fri, 13 May 2022 17:53:48 GMT

hello @jagan

This scheme it's really interesting for me.

Actually I have the problem that I build a model with more fact table.

This is the link at the post in the qlik forum...
https://community.qlik.com/t5/New-to-Qlik-Sense/Star-schema-suggestion/m-p/1929149#M205415

can you help me?

Re: How many fact tables will be there in star schema?

vinieme12 — Tue, 17 May 2022 07:50:38 GMT

This is going to be an Unpopular Opinion, but I disagree with comments stating that a Star Schema can only have ONE Fact table

As long as your Model Resembles a STAR its a STAR schema

If your Model Resembles a SNOWFLAKE its a SNOWFLAKE schema

Re: How many fact tables will be there in star schema?

MiguelHathaway — Tue, 17 May 2022 10:40:30 GMT

You should not connect fact tables directly. If it's the same transaction, combine the fact tables in a single one. Otherwise find the dimension that allow you to Analyse them both simultaneously

Re: How many fact tables will be there in star schema?

alexandernatale — Tue, 17 May 2022 12:02:45 GMT

I believe that the scheme proposed by @jagan is quite functional. The fact tables cannot be linked together because they are too different production factors and different traces.

In the @jagan model there is 2 table fact connected to more dimension table...
With this method the star scheme it will have a heart (made up of one or more table facts) and then the dimensions tables.

Re: How many fact tables will be there in star schema?

qlikviewforum — Wed, 09 Aug 2023 10:25:36 GMT

@jagan If both the FACT table have different data as in your diagram is that also is considered as Star Schema? Generally they say Star Schema can have only one FACT table. Please confirm...

Re: How many fact tables will be there in star schema?

mansoorsheraz — Wed, 09 Oct 2024 19:47:53 GMT

So in this case if I have to check for a city e.g. New York City, how would I get all the retailers, products, sales, purchases, suppliers for it because we have different named dimensions here e.g. sup_city, ret_city

Also in this case we may end up with circular reference in Qlik ( i am, not so sure) but it looks like it will e.g. time > sales > products > purchase > time