Calc fields(rel. to 3rd db) and slow w.c. requests

[amk]

I've got a database, Db1 , shared by the w.c. ,and a layout with some 10 fields.

Db1 is related to another database, Db2, not shared via the w.c. Db1 displays data from Db2 on its layout + a couple of fields from a third database, Db3.

In the Db2, I use a couple of calculation fields to get the data (from db3) on the layout of the web database. Thus:

web database

..........................................

1) some fields from db2:

relToDB2::fieldA

relToDB2::fieldB etc.

2) fields from db3, via calc field:

relToDB2::calc_FieldC

db2

..........................................

fieldA

fieldB

calc_fieldC

= db3::fieldC

db3

..........................................

fieldC

Now, I realize testing a simple find query with PHP - restricting the search with a required value on one of the calc fields - that such calculation fields slow down the request, since they are processed at runtime.

The following FM message (hopefully translated correctly) turns up:

"Number of non- indexed records left " + a huge number

"Processing field "calc_fieldC"

Question:

1. Should I avoid calc fields, and make direct connections to db3 from

db1?

2. Will the setup of having a special web database referencing some ten or so fields in a second non web-enabled db also considerably slow down requests also, i.e. compared with if all fields were on one and the same db)?