Assembly loads slow using specific (custom) revision rule.
Also in TC RAC Structure Manager, the same Revision Rule causes problems.
Revision rule contains several detailed rules searching for statuses.
This seems specific to Oracle 12.1.0.2.
Solution
Set Oracle parameter optimizer_adaptive_features=FALSE
This setting could influence statistics. To ensure no impact, it might help to regenerate statistics after making optimizer_adaptive_features=FALSE.
Consult an Oracle administrator and analyze if this setting is appropriate for your configuration!
Notes
http://solutions.industrysoftware.automation.siemens.com/view.php?si=sfb-teamcenter-10828