The figure compares settings of the COMPATIBLE initialization parameter for release 8.0, release 8.1, and release 9.0.0.

In release 8.0:

• Can be set to 8.0.x only.
• The default setting is 8.0.0.
• The lowest possible setting is 8.0.0.
• The highest possible setting is your current release.
• Cannot be set to any Oracle7 release or lower.
• Cannot be set to any release higher than your current release, including 8.1.0 and higher.

In release 8.1:

• Can be set to 8.1.y or 8.0.x.
• The default setting is 8.0.0.
• The lowest possible setting is 8.0.0.
• The highest possible setting is your current release.
• Cannot be set to any Oracle7 release or lower.
• Cannot be set to any release higher than your current release, including 8.2.0 and higher.

In release 9.0.0:

• Can be set to 9.0.z or 8.1.y.
• The default setting is 8.1.0.
• The lowest possible setting is 8.1.0.
• The highest possible setting is your current release.
• Cannot be set to any 8.0 release or lower.
• Cannot be set to any release higher than your current release, including 9.1.0 and higher.