Oracle Text Index - Trailing Search when the String has spaces

Question

Hi Am trying to use CONTAINS to tune a trailing LIKE search.  But it's not working when the string has spaces in between them
For e.g in say if table person has column name which has following values
JOHN
FRED JOHNSON
JOHN ROBERTS
select * from person where name like 'JOHN%'
Above query will give JOHN and JOHN ROBERTS. If i use CONTAINS As below
select * from person where CONTAINS(name,'JOHN%',1) > 0
It brings back all three records. If i remove spaces in column itself, its working bit if i try to remove spaces in Query, i am getting a Text error as i have Text index only on the name column.  I would like to know is it possible to use CONTAINS but get same result set on trailing search as how a normal LIKE will do.
Below is how i did Index creation
create index txt_idx1 on person (name)
indextype is ctxsys.context
parameters('DATASTORE ctxsys.default_datastore');

Answer 1

You could use some method, like a multi_column_datastore or user_datastore to append some specific starting characters, then include those in your search, as shown below.
SCOTT@orcl12c> CREATE TABLE person
  2    (name  VARCHAR2(60))
  3  /
Table created.
SCOTT@orcl12c> INSERT ALL
  2  INTO person VALUES ('JOHN')
  3  INTO person VALUES ('FRED JOHNSON')
  4  INTO person VALUES ('JOHN ROBERTS')
  5  SELECT * FROM DUAL
  6  /
3 rows created.
SCOTT@orcl12c> BEGIN
  2    CTX_DDL.CREATE_PREFERENCE ('test_ds', 'MULTI_COLUMN_DATASTORE');
  3    CTX_DDL.SET_ATTRIBUTE ('test_ds', 'COLUMNS', '''start ''||name||'' end'' name');
  4  END;
  5  /
PL/SQL procedure successfully completed.
SCOTT@orcl12c> create index txt_idx1 on person (name)
  2  indextype is ctxsys.context
  3  parameters('DATASTORE test_ds')
  4  /
Index created.
SCOTT@orcl12c> select * from person where CONTAINS(name,'start JOHN%',1) > 0
  2  /
NAME
JOHN
JOHN ROBERTS
2 rows selected.
SCOTT@orcl12c>