incompatible fields in Where statement.

DearSAP Guru's

I have a scenario like this. Not sure this is possible or not. Thought i just post this question hope some one has answer to this.

Assume  I have matnr (char12) in itab1 and want to select some data from a different table using this matnr from itab1. Let's say if matnr in table2 is 20 char. Is it possible to do this? I am just concerned about the performance.

select * from table2 into itab2

for all entries in itab1 where matnr (char20) = itab1-matnr (char12).

Thanks

Rajesh