To Split and Gzip at the same time

splitgz.awk

#!/usr/bin/env gawk -f 
BEGIN { id = 0; 
  cmd = "gzip -c -2"; 
  ext = ".gz";
  file = sprintf("%04d%s",id, ext); 
  print "Opening new file " file " at " NR " rows";
  count = 1000000;
}

# Use pipes 
{ print | cmd " > " file }

# Close pipe every 100k lines
NR % count == 0 {
  close(cmd " > " file );
  id = id + 1;
  file = sprintf("%04d%s",id,ext); 
  print "Opening new file " file " at " NR " rows";
}

END {
  print "Ending stream at " NR " rows"
  # pipes are automatically closed
}