Behavior of VARCHAR and COMPRESSed columns in SPOOL - forum topic by hemanth_td

Hello,
Could someone please answer:
1. REGARDING VARCHAR:
I have a table with one of the columns defined as VARCHAR(255) even though the char length would never exceed 15 characters.
Is there any performance impact in defining a column as VARCHAR(255) against defining it as VARCHAR(15).
I got to know from some one that --> When we query a table defined with VARCHAR columns, VARCHAR fields are expanded to their full limit in SPOOL.
Greater the spool file size, more the number of I/O hits --> So there is a significant performance degradation by defining the VARCHAR columns with "unnecessary" greater lengths.
Is my understanding correct? 
2. REGARDING COMPRESS
Will the column COMPRESSions be lost when a table (defined with some multi value column compressions) is read into spool?
 
Thanks in advance!