Using oracle text on a non-materialized view

Question

I'm having trouble tracking down an error when using oracle text on a non-materialized view (indexes are on the referenced columns). My database has a users table and a user history table which saves the old values when a user profile changes. My view performs a "union all" so I can select from both at once.
I would like to use oracle text to perform a "contains" on the view whenever someone signs up to see if any current users or historical entries contain the desired username.
The following works fine:
contains(user_history_view, 'bill')but when I reference anything in the contains clause, i get a "column is not indexed" error:
contains(user_history_view, signup.user_name) --signup.username is 'bill'Here is a stripped-down demonstration (I am using version 10.2.0.4.0)
create table signup (
  signup_id   number(19,0) not null,
  signup_name varchar2(255),
  primary key (signup_id)
create table users (
  user_id   number(19,0) not null,
  user_name varchar2(255),
  primary key (user_id)
create table user_history (
  history_id number(19,0) not null,
  user_id    number(19,0) not null,
  user_name  varchar2(255),
  primary key (history_id),
  foreign key (user_id) references users on delete set null
create index user_name_index on users(user_name)
indextype is ctxsys.context parameters ('sync (on commit)');
create index user_hist_name_index on user_history(user_name)
indextype is ctxsys.context parameters ('sync (on commit)');
create index signup_name_index on signup(signup_name)
indextype is ctxsys.context parameters ('sync (on commit)');
create or replace force view user_history_view
(user_id, user_name, flag_history) as
select user_id, user_name, 'N' from users
union all
select user_id, user_name, 'Y' from user_history;
--user bill changed his name to bob, and there is a pending signup for another bill
insert into users(user_id, user_name) values (1, 'bob');
insert into user_history(history_id, user_id, user_name) values (1, 1, 'bill');
insert into signup(signup_id, signup_name) values(1, 'bill');
commit;
--works
select * from user_history_view users, signup new_user
where new_user.signup_id = 1
and contains(users.user_name, 'bill')>0;
--fails
select * from user_history_view users, signup new_user
where new_user.signup_id = 1
and contains(users.user_name, new_user.signup_name)>0;I could move everything into a materialized view, but querying against real-time data like this would be ideal. Any help would be greatly appreciated.

Answer 1

Hi,
this is to my knowledge not possible. It is hard for Oracle to do, think about a table with many rows, every row with that column must be checked. So I think only a single varchar2 is possible. Maybe for you will a function work. It is possible to give a function as second parameter.
function return_signup
return varchar2
is
  l_signup_name signup.signup_name%type;
begin
  select signup_name
  into l_signup_name
  from signup
  where signup_id = 1
  and rownum = 1
  return l_signup_name;
exception
  when no_data_found
  then
    l_signup_name := 'abracadabra'; -- hope does not exist
    return l_signup_name;
end;Now you can use above function in the contains.
select * from user_history_view users --, signup new_user
--where new_user.signup_id = 1
where contains(users.user_name, return_signup)>0;I didn't test the code! Maybe you have to adjust the function for your needs. But it is a idea how this can be done.
Otherwise you must make the check by normaly check the columns by simple using a join:
select * from user_history_view users, signup new_user
where new_user.signup_id = 1
and users.user_name = new_user.signup_name;Herald ten Dam
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