Database start at Boot Time

We may want that, our database should start at the boot time of a machine. To do this in solaries we have to edit the following file,
/var/opt/oracle/oratab

We will get some lines like,

XXXXX:/oracle/app/oracle/product/10.2.0/db_1:N

Entries are of the form:
$ORACLE_SID:$ORACLE_HOME:

The first and second fields are the system identifier and home directory of the database respectively. The third filed indicates to the dbstart utility that the database should , "Y", or should not, "N", be brought up at system boot time.

Multiple entries with the same $ORACLE_SID are not allowed.