optimizer_features_enable and compatible

We are running Oracle 9i (9.2.0.5) on SunSolaris.
I have heard or seen mixed values for the below 2 parameters. What should be the ideal values?

optimizer_features_enable=9.2.0
compatible=9.2.0

OR

optimizer_features_enable=9.2.0.5
compatible=9.2.0.5


Thanks in advance!

tahiti.oracle.com

Both those parameters specify *the release* to which they comply. And the particular release of the database is specified *by the first three digits* - the forth and fifth digit specify only applied patchset/patches.

So if your version number is 9.2.0.5, then your actual release is 9.2.0, and that's all that those two parameters will take into account. Even if you set them to more precise value, e.g. 9.2.0.5, they will ignore anything after the third digit.