It depends on your oracle version.From 10gR2 (iirc) onwards you can specify append keyword in the spool command
spool file.a append Here is the doc reference: http://download.oracle.com/docs/cd/B19306_01/server.102/b14357/ch12043.htm#sthref3036 Best regards Maxim -- //www.freelists.org/webpage/oracle-l