topic Re: Outer Join as Cartesian Product in QlikView

Outer Join as Cartesian Product

Wed, 25 Nov 2020 16:16:04 GMT

I am applying Outer join to get Cartesian product on 2 tables (without any common key ). table 1 has 500000 rows and tale 2 has 5000 rows . it is showing "execution of script failed " error.

Is it any QV limitation /

Also what can be a better alternative ?

Re: Outer Join as Cartesian Product

sunny_talwar — Mon, 18 Apr 2016 15:34:24 GMT

Might be memory (RAM) constraints?

UPDATE: Check memory performance while reloading the application

Re: Outer Join as Cartesian Product

Peter_Cammaert — Mon, 18 Apr 2016 15:36:44 GMT

An alternative to do what?

Re: Outer Join as Cartesian Product

Colin-Albert — Mon, 18 Apr 2016 15:40:33 GMT

Do you really need a Cartesian join between these tables 500,000 x 5,000 = 2,500,000,000 rows!

Hope you've got plenty of RAM!

Perhaps it would be better to explain what you are trying to achieve. A Cartesian join is rarely the correct answer.

Re: Outer Join as Cartesian Product

swuehl — Mon, 18 Apr 2016 16:03:06 GMT

You can also try running your script with a limited amount of records (e.g. using FIRST) just to check if there is any other problem with your script.

You can then also consider not JOINing the full tables, but creating a link table made by a cartesian JOIN of the two primary keys of your two tables.

Not sure if this will resolve your issue, since I have no clue what you want to achieve at the end.

Re: Outer Join as Cartesian Product

Gysbert_Wassenaar — Mon, 18 Apr 2016 16:06:33 GMT

Also what can be a better alternative ?

Not trying it in the first place.

Why do you think you need to create a 2.5 billion row table?

Re: Outer Join as Cartesian Product

Wed, 20 Apr 2016 05:25:28 GMT

Thanks all !!...Yes it was a business requirement to process that much data. Later on we limited the data by applying conditions on that and it worked.

Re: Outer Join as Cartesian Product

Colin-Albert — Wed, 20 Apr 2016 12:33:07 GMT

Surely there must be a better way to get your results without using a Cartesian join.

Perhaps you should review your data model.

Perfect Your QlikView Data Model

Best Practices for Data Modelling