topic Re: Join or mapping in QlikView

Join or mapping

manoranjan_d — Wed, 14 Jun 2017 06:53:00 GMT

Hi join is fast or mapping is fast according to performance wise?

Re: Join or mapping

Anil_Babu_Samineni — Wed, 14 Jun 2017 06:55:44 GMT

I know, you may have some ideas. But read this, You may get to know which is best performance function

Don't join - use Applymap instead

Re: Join or mapping

mbrdenmark — Wed, 14 Jun 2017 06:59:14 GMT

Joins are generally faster than applymap in terms of raw performance.

Source: QlikView Developer course

Re: Join or mapping

prma7799 — Wed, 14 Jun 2017 06:59:23 GMT

The reason I have used applymap a lot is (as opposed to join)

It only picks up the first record. (although not exists can be used to eliminate multi records but I feel its safer using applymap when a second entry for one record must be ignored)
Missing records can be given a name. Like 'Missing' . Or can be used to group records. So an excel spreadsheet will have the Focus Customers and the rest will be grouped as 'Other

The disadvantage are

applymap can only loookup one record. Say the Customer name for the Cust Number but not also the Cust Telephone number. Unless another apply map is used
Its more work to set up. Join is simple

Please go through below links

Mapping Load / Apply Map versus Left Join

Don't join - use Applymap instead

Re: Join or mapping

prieper — Wed, 14 Jun 2017 11:22:18 GMT

Fully support PM and am also very much in favour of APPLYMAP().

One small thing to add: Applymap does not cause an error, if reference-tables are not existings / misspelled.

Peter

Re: Join or mapping

prma7799 — Tue, 27 Jun 2017 07:39:11 GMT

manoranjan.d‌ Please close this thread by giving correct or helpful .

Re: Join or mapping

Kushal_Chawda — Tue, 27 Jun 2017 07:53:37 GMT

manoranjan.d‌

Request you to please close the thread by marking answers as correct or helpful. Many of your previous threads are still open even there are helpful answers