topic Re: Left keep and Left join in QlikView

Left keep and Left join

Wed, 03 Sep 2014 08:43:27 GMT

Hi,

While development, in which cases, should I prefer Left Keep over Left Join, assuming the fact that they produce same result set (though number of tables differ in data model)?

Thanks.

Re: Left keep and Left join

adiarnon — Wed, 03 Sep 2014 09:00:59 GMT

mybe this help -

Difference between left Keep vs left Join

left keep

there alot of disccusion about this subject so you can try to search

adi

Re: Left keep and Left join

tresB — Wed, 03 Sep 2014 09:03:39 GMT

If you Join the tables, number of table hoppings would reduce and thus makes the front end performance better. On the other hand perhaps (not tested) Keep would vtake less time during reload in case of a very big data table in join question. Here to mention, in such performance issues ther is one more very effective way called AppyMap could be proven helpful.

Re: Left keep and Left join

ashfaq_haseeb — Wed, 03 Sep 2014 09:06:39 GMT

Hi,

have a look at attached document

Regards

ASHFAQ

Re: Left keep and Left join

aveeeeeee7en — Wed, 03 Sep 2014 09:11:04 GMT

See this post for clarity:

http://community.qlik.com/thread/39177

Regards

Aviral Nag

Re: Left keep and Left join

engishfaque — Wed, 03 Sep 2014 09:14:15 GMT

Dear qv_learner,

The keep prefix is similar to the Join prefix. Just as the join prefix, it compares the loaded table with an existing named table or the last previously created data table.

But instead of joining the loaded table with an existing table, it has the effect of reducing one or both of the two tables before they are stored in QlikView, based on the intersection of table data.

Reference: QlikView Referene Manual

Kind regards,

Ishfaque ahmed

Re: Left keep and Left join

MayilVahanan — Wed, 03 Sep 2014 09:16:01 GMT

Its based on your requirement.

If you don't want to join with the parent table but "you need to reduce the data based on the parent table and do some action in your table". In that case, you can prefer keep.

Please refer

Understanding Join, Keep and Concatenate

Re: Left keep and Left join

Wed, 03 Sep 2014 09:54:44 GMT

Thanks for the attachment Ashfaq.