来源于：
Windows Registry Missing Autostart Attribute after In-Place Upgrade of Oracle Database from 11.2.0.3 to 11.2.0.4 (文档 ID 1963067.1)
APPLIES TO:
Oracle Database - Enterprise Edition - Version 11.2.0.1.0 to 11.2.0.4 [Release 11.2]Information in this document applies to any platform.
SYMPTOMS
The database auto start attribute in windows registry was removed on upgrade of Oracle database from 11.2.0.3 to 11.2.0.4 (In place upgrade). This prevents Oracle Database to restart on reboot of the system.
CAUSE
For In-place upgrade you will need to detach old 11.2.0.3 ORACLE_HOME first , that is where it will delete ORA_AUTOSTART registry entry.
SOLUTION
As detach home operation is deleting registry entry , you will need to add ORA_AUTOSTART registry entry manually after upgarde using below command:
oradim -EDIT -sid -startmode AUTO
REFERENCES
NOTE:556610.1 - Script to Collect DB Upgrade/Migrate Diagnostic Information (dbupgdiag.sql)