Error in Extrack Database

i have file Dump > 500 MB
when i execute " gunzip -c data.dump.gz | psql internal "

some error message emerged as follows :
FATAL 1:  copy: line 2516273, Memory exhausted in AllocSetAlloc()

what might be happen with the process ??
how to solve the problem ??

i use sparc sun solaris 2.6, postgres 6.5.3, memory 256 MB

thanks
Nizomi