write to file with quick

[Jari.Kaljunen@teliasonera.com]

Hello,

I am writing to 

File: ASC600
Organization: SEQUENTIAL
Type: RMS
Open: ASC600
Record Format: Variable
Supersede: No
Records & Sizes: ASC600 600 bytes
Item Type Size Occ Offset
REC600 CHARACTER 600 

in quick using let and put as follows

let rec600 = "<HeaderRef2>" + asc(arnr of arenden,8) + asc(parmblnr,2) &
+ atgkod of atgkoder + "</HeaderRef2>"

put asc600 reset


The performance is very poor. The administrator believs that quick closes and opens the file all the time. 
Can that be true?
What should I do?

We are creating an xml-file (it will be about 5 GB) with data from several tables and our solution with qtp needed too many subfiles and sortings using lots of space.

/Jari