Create a graph in HCP Trial

Greetings Experts,

I am trying to adopt the features of HANA's  Graph Engine, using the Hana Cloud Platform on a Trial Account.

By executing this command:

ALTER SYSTEM ALTER CONFIGURATION ( 'indexserver.ini', 'System' )
SET ( 'graph_engine', 'enable' ) = 'yes'
WITH RECONFIGURE

I get the following error:

Could not execute 'ALTER SYSTEM ALTER CONFIGURATION ( 'indexserver.ini', 'System' ) SET ( 'graph_engine', 'enable' ) = ...'

SAP DBTech JDBC: [258]: insufficient privilege: Not authorized

I would really appreciate it, if you could give some advice on how to overcome this issue,or provide some insight about the limitations of HCP.

Best,

Ilias Katsabalos