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I want to change the OPTIMIZER_FEATURES_ENABLE parameter in a local installation of Oracle 9i (32bit Enterprise Edition running on Windows Server 2003) in an attempt to reproduce a performance issue reported by a client but I can't figure out how to do it. Both ALTER SESSION and ALTER SYSTEM statements trigger this error (even if run as SYS):

ORA-02095: specified initialization parameter cannot be modified

How can I change it?


The steps I followed (thanks to Gary's answer) were this:

  1. Create an empty file: C:\oracle\ora92\DBS\INIT.ORA

  2. Edit the file to add: optimizer_features_enabled = 8.1.7

  3. Launch Windows service manager

  4. Restart the service called OracleServiceFOO, where FOO is my instance name

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up vote 2 down vote accepted

It's a static parameter so it needs to be changed in the pfile / spfile and then the instance restarted.

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Thank you. The article omits many things but it helped me to figure out the necessary steps. I've updated the question to reflect them. – Álvaro González Jun 3 '11 at 8:14

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