I have a record with effdt , effseq as keys in the first 2 fields in the structure and they are foll

I have a record with effdt , effseq as keys in the first 2 fields in the structure and they are followed by additional keys

I discovered that has a severe impact upon query manager in that the effdt subquery only contains select max(effdt)   with no connection to the other keys.   The result is only 1 row is returned, the max effective dated row in the table.

Is there a document that I can refer to that tells me what additional impact there will be within component processing etc of having a record definition like this so the best practice is to put effdt , effseq ... somewhere else in the record structure instead ?