Best Practice for AiF Queries

[ideveloper]

Hi.

I have a Query for an AiF-Service which is build with ca. 5 Tables.
The disadvantage of this is the overhead of the Service schema. It could deliver me all fields of the tables, but I need only 5 of them.

Is it a best practice solution to build the Query with the "drag and drop" Method or should I create a display field in the custom table, where I try to get the values from the according tables.

Or is there an another solution to minimize the schema?

Tanks.

Regards
ideveloper