HP's startup stuff can be a little tricky if you don't know what you are doing. Having said that, it ain't no magic at all.
I am assuming you have a startup/shutdown script for your database right ? If yes, place them in /sbin/init.d directory to be compliant with the standards (otherwise they can be placed anywhere)
Then, decide on which run-level it needs to start, 1 thru 4. The rc script at the startup time, goes thru these run-levels in an ascending order. Run level directories are
$ ll -d /sbin/rc*d
dr-xr-xr-x 2 bin bin 1024 May 6 14:09 /sbin/rc0.d
dr-xr-xr-x 2 bin bin 3072 May 6 2008 /sbin/rc1.d
dr-xr-xr-x 2 bin bin 3072 May 6 14:09 /sbin/rc2.d
dr-xr-xr-x 2 bin bin 1024 Feb 13 2008 /sbin/rc3.d
dr-xr-xr-x 2 bin bin 96 Apr 25 2007 /sbin/rc4.d
rc0.d is reserved for shutting down the system related processes, like syncer, LVM daemon and what-not and unless your database is an integral part of your OS, you should not be placing anything there.
Since these run levels get executed in ascending order, you need to know what prerequisites need to be running prior to launching your database and decide where your startup needs to go. Most layered products like databases and such, usually start at run-level 3
In each run level, you will see symbolic links to start up scripts placed in (generally) /sbin/init.d, named similar to "SxxxScriptName.sh", where the xxx is a numeric sequence number. When the rc script runs, it goes through the numbers, yes, as you guessed, in an ascending order.
In each run level you also will see symbolic links starting with letter K. Those are the "Kill" scripts. Kill scripts are placed one run-level above the level application starts. Highest numbered S script usually complimented by the lowest numbered K script in the next run level above this one.
so, if we say you will start your database as the last app on run level 3, it needs to be killed as first thing on run level 4, so hypothetical commands you will need to run are as follows:
cp /path/to/my/database_start_stop_script /sbin/init.d
ln -s /sbin/rc3.d/S900MyDbStart /sbin/init.d/database_start_stop_script
ln -s /sbin/rc2.d/K100MyDbStop /sbin/init.d/database_start_stop_script
make sure your start/stop script has execute permissions and your links are not destroying existing links (if so, adjust the xxx values by few numbers above or below)
Hope this helps