When upgrading for Metaframe XP 1.0 FR3 SP4 to Presentation Server 4 the PS4 Database Connection Server log reports "Resource Manager summary database schema update for version 27 failed" when using an Oracle 9i Summary Database.

To resolve the issue:

Run the Presentation Server Console from the PS4 server
Connect to the PS4 server at the Presentation Server Console logon
Select Resource Manager, Summary Database, Configure
Disable the Summary Database

Copy the "C:\Program Files\Citrix\Citrix Resource Manager\SDBSchema\SDBSchema_Oracle8.sql" file to the Oracle bin directory "C:\Oracle\920\bin"
Start a command prompt and change to the "C:\Oracle\920\bin" directory
Run the command: sqlplus <username>@<SummaryDatabase> @SDBSchema_Oracle8.sql

Check the SCHEMAVERSION in sqlplus with:
SELECT * from SCHEMAVERSION;

If multiple SCHEMAVERSIONs are reported e.g. (27 and 41) delete the incorrect version with the following sqlplus command:
DELETE FROM SCHEMAVERSION WHERE VERSION='27';

Run the Presentation Server Console from the PS4 server
Connect to the PS4 server at the Presentation Server Console logon
Select Resource Manager, Summary Database, Configure
Enable the Summary Database and test the connection
Click Update Now and check the log

Resource Manager Summary Database Schema Versions are documented in http://support.citrix.com/article/CTX106174

MF XP FR2 RM Summary Database Update for Schema Version : (18)
RME102W007 RM Summary Database Update for Schema Version : (21)
RME102W011 RM Summary Database Update for Schema Version : (22)
MF XP FR3 RM Summary Database Update for Schema Version : (24)
RME102W013 RM Summary Database Update for Schema Version : (25)
RME103W006 RM Summary Database Update for Schema Version : (26)
RME103W011 RM Summary Database Update for Schema Version : (27)
MPS 3.0 RM Summary Database Update for Schema Version : (40)
CPS 4.0 RM Summary Database Update for Schema Version : (41)