Explain plan over primary key column

[Sumit Nigam]

Hi,
I have a table as:
CREATE TABLE EXP (ID BIGINT NOT NULL PRIMARY KEY, TEXT VARCHAR);
If I explain the select:
EXPLAIN SELECT ID FROM EXP;
Then it shows CLIENT 1-CHUNK PARALLEL 1-WAY FULL SCAN OVER EXP ....
I assume it still uses rowkey. Or is it should have shown using rowkey in 
explain plan?
Also, is it a good idea to declare VARCHAR(n) vs plain VARCHAR? Does it save 
some space?
Thanks,Sumit