crontab and top

hi everyone

how can i use crontab and top for record information about cpu in a file?
i wrote this command in crontab:

#crontab -e

*/5 * * * * top >> test.txt

is that right?

how can i recored cpu usage of processes like oracle in top and print in a file?thanks in advance

---------- Post added at 03:18 PM ---------- Previous post was at 02:26 PM ----------

hi again i could take advantage from this command:

*/5 * * * * /usr/bin/top b -S >> /root/cront.log 2>&1

but how can i filter by top COMMAND (for example oracle COMMAND) ?