Synthethic keys

[Aakashdata]

Do you really think the formation of a synthetic keys considered bad in Qlikview? If not please can you explain me.

[Somasundaram]

Formation of synthetic keys is not bad, but, It's poor data model.Try to eliminate the synthetics keys.

[rinugour]

In QlikView, if there are several fields in common between two or more than two tables then a table containing the set of composite keys is made. This table is identified by a synthetic key ($Synkey).

However, this approach by QlikView to manage overriding fields consider as a sign of poorly designed data model. The user must check for logical errors that in turn reflects into the script not making a good data model.

[Shubham_Deshmukh]

NO its not bad, though it is sign of poor data model but some times it plays an important role where you don't want data islands.

Depends on situation.

[rinugour]

In QlikView, if there are several fields in common between two or more than two tables then a table containing the set of composite keys is made. This table is identified by a synthetic key ($Synkey).

However, this approach by QlikView to manage overriding fields consider as a sign of poorly designed data model. The user must check for logical errors that in turn reflects into the script not making a good data model.

[jonathandienst]

Synthetic keys are not inherently bad -- in fact they are a good solution if you truely need a composite key between two tables -- however good data model design will in most cases eliminate the need for a composite key. 

However, unintended synthetic keys are usually a sign of a scripting error (eg not dropping a temporary work table) or a poorly thought through model design. And nested synthetic keys and associative loops are always a bad thing, as it is very hard to get the expected results in such as model and performance may be very poor as well.

[Brett_Bleess]

Below is a Design Blog post from Henric Cronstrom regarding Synthetic Keys that may be useful as well:

Synthetic Keys

Regards,
Brett