"Stram Database operator with Postgresql"

Hi together,
until recently i worked with RM on my Postgres DB with the read DB operator. It works perfect. Because of fast growth I have to change the operator to the Stream DB operator.
In my DB i have already a PK named id. But when iI try to use this one i became an error:
SEVERE: Database error occurred: FEHLER: Syntaxfehler bei »IDENTITY«
Position: 68
com.rapidminer.operator.UserError: Database error occurred: FEHLER: Syntaxfehler bei »IDENTITY«
Position: 68
at com.rapidminer.operator.io.CachedDatabaseExampleSource.createExampleSet(CachedDatabaseExampleSource.java:96)
at com.rapidminer.operator.io.AbstractExampleSource.read(AbstractExampleSource.java:52)
at com.rapidminer.operator.io.AbstractExampleSource.read(AbstractExampleSource.java:36)
at com.rapidminer.operator.io.AbstractReader.doWork(AbstractReader.java:126)
at com.rapidminer.operator.Operator.execute(Operator.java:866)
at com.rapidminer.operator.execution.SimpleUnitExecutor.execute(SimpleUnitExecutor.java:51)
at com.rapidminer.operator.ExecutionUnit.execute(ExecutionUnit.java:711)
at com.rapidminer.operator.OperatorChain.doWork(OperatorChain.java:375)
at com.rapidminer.operator.Operator.execute(Operator.java:866)
at com.rapidminer.Process.run(Process.java:949)
at com.rapidminer.Process.run(Process.java:873)
at com.rapidminer.Process.run(Process.java:832)
at com.rapidminer.Process.run(Process.java:827)
at com.rapidminer.Process.run(Process.java:817)
at com.rapidminer.gui.ProcessThread.run(ProcessThread.java:63)
Caused by: org.postgresql.util.PSQLException: FEHLER: Syntaxfehler bei »IDENTITY«
Position: 68
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:555)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:403)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:395)
at com.rapidminer.example.table.IndexCachedDatabaseExampleTable.createRMPrimaryKeyIndex(IndexCachedDatabaseExampleTable.java:231)
at com.rapidminer.example.table.IndexCachedDatabaseExampleTable.createIndex(IndexCachedDatabaseExampleTable.java:126)
at com.rapidminer.example.table.IndexCachedDatabaseExampleTable.<init>(IndexCachedDatabaseExampleTable.java:108)
at com.rapidminer.operator.io.CachedDatabaseExampleSource.createExampleSet(CachedDatabaseExampleSource.java:92)
... 14 more

In the documentation I read that I have to generate a new attribut named rm_index. I did but the problem and the error is the same.
I think it is a problem with postgresql but knows anybody a solution?