SQL to run after write feature writer

Hi,

I'm trying to create Index on attributes for a feature class inside FGDB. I'm using SQL to run after write option available in Feature writer. But i'm getting invalid sql statement. But it works fine when I tested in sql developer. Below is the sql,

FME_SQL_DELIMITER ;

DECLARE

strColumnNames VARCHAR(200);

P_COLUMN_NAME VARCHAR(200);

strStatement VARCHAR(2000);

P_INDEX_NAME VARCHAR(200);

P_TABLE_NAME VARCHAR(200);

ind NUMBER;

indexCount NUMBER;

BEGIN

strColumnNames := '@Value(idx)';

P_TABLE_NAME:= '@Value(processname)_WM';

ind := instr(strColumnNames,',');

indexCount:= 1;

WHILE ind > 0 LOOP

P_COLUMN_NAME := SUBSTR(strColumnNames,1,ind-1);

P_INDEX_NAME:= P_COLUMN_NAME || '_' || indexCount;

strStatement := 'CREATE INDEX ' || P_INDEX_NAME || ' ON ' || P_TABLE_NAME || '(' || P_COLUMN_NAME || ')';

dbms_output.put_line('Statement is : ' || strStatement);

strColumnNames := SUBSTR(strColumnNames,ind+1,LENGTH(strColumnNames)-ind);

ind := instr(strColumnNames,',');

indexCount := indexCount + 1;

END LOOP;

P_COLUMN_NAME := strColumnNames;

P_INDEX_NAME:= P_COLUMN_NAME || '_' || indexCount ;

strStatement := 'CREATE INDEX ' || P_INDEX_NAME || ' ON ' || P_TABLE_NAME || '(' || P_COLUMN_NAME || ')';

dbms_output.put_line('Statement is : ' || strStatement);

END;

Not sure where I'm going wrong and also is it right to run this sql on FGDB?

Thanks