Multilingual XML Approach

Question

Hi,
I need to discuss one thing regarding multilingual implementation for an application. The requirement is given below.
1. only master data(user entry) of the application will support multilingual.
2. Application will support 'n' languages becuase it will be installed for each country.
Our Approach:
1. We created one column with datatype XMLTYPE and store data as XML. The data is stored like below.
  <ROOT>
<ROW LANG_ID="22">JROEMVRTFK</ROW>
<ROW LANG_ID="34">سشيشي</ROW>
<ROW LANG_ID="4">نههلت</ROW>
  </ROOT>
where LANG_ID is the language id of language master table.
2. We created one index for XMLTYPE data type.
     CREATE INDEX <<index_name>> ON <<table_name>> (<<column_name>>) INDEXTYPE IS XDB.XMLINDEX PARAMETERS ('PATHS (INCLUDE (/ROOT/ROW))');
3. We created 10,000 rows into that table.
Why this Approach:
Let's take an example. Assume that, Client 1 wants the application to support 3 languages. Client 2 wants , the application to support 4 languages and so on. For a column based approach our database patch will differ for each client. So for Client 3, who wants support for 2 languages the system will be isolated from our base version of database.
Performance:
1. From the performance aspect, the query execution will be 4 times slower than the traditional column wise approach. The query will look like:
               SELECT
TRIM(EXTRACT(VALUE(c), '/ROW/@LANG_ID')) LANG_ID,
                        TRIM(EXTRACT(VALUE(c), '/ROW/text()')) STATE_NAME
               FROM
STATE_MASTER d,
                        TABLE(XMLSEQUENCE(EXTRACT(d.STATE_NAME,'/ROOT/ROW'))) c
                WHERE
                                  EXTRACT(VALUE(c), '/ROW/text()').GETSTRINGVAL() LIKE ‘ACN%’
Question:
1.  Is it the correct approach?
2. If not what will be the approach for supporting 'n' languages for a single database.
3. How to improve the performance?

Answer 1

The rewritten XML approach :
-- master table with Binary XMLType column
create table state_master (id integer, xml_state_name xmltype)
xmltype column xml_state_name store as securefile binary xml;
-- structured XMLIndex
create index state_master_sxi on state_master (xml_state_name)
indextype is xdb.xmlindex
parameters (q'~
  XMLTABLE state_master_xt
  '/ROOT/ROW'
  PASSING xml_state_name
  COLUMNS lang_id    number         PATH '@LANG_ID'
        , state_name varchar2(4000) PATH '.'
~'
-- secondary index on LANG_ID
create index state_master_xt_lang_id_i on state_master_xt (lang_id);
SQL> insert into state_master values (
  2    1
  3  , xmlparse(document '<ROOT><ROW LANG_ID="1">Hello</ROW><ROW LANG_ID="2">Bonjour</ROW></ROOT>')
  4  );
1 row created.
SQL> insert into state_master values (
  2    2
  3  , xmlparse(document '<ROOT><ROW LANG_ID="1">Goodbye</ROW><ROW LANG_ID="2">Au revoir</ROW></ROOT>')
  4  );
1 row created.
SQL> set autotrace on explain
SQL> set lines 200
SQL>
SQL> select t.id, x.lang_id, x.state_name
  2  from state_master t
  3     , xmltable('/ROOT/ROW' passing t.xml_state_name
  4         columns lang_id    number         path '@LANG_ID'
  5               , state_name varchar2(4000) path '.'
  6       ) x
  7  ;
  ID    LANG_ID STATE_NAME
   1          1 Hello
   1          2 Bonjour
   2          1 Goodbye
   2          2 Au revoir
Execution Plan
Plan hash value: 1735897579
| Id  | Operation                    | Name                     | Rows  | Bytes | Cost (%CPU)| Time  |
|   0 | SELECT STATEMENT             |                          |     4 |   144 |     5   (0)| 00:00:01 |
|   1 |  NESTED LOOPS                |                          |       |       |            |       |
|   2 |   NESTED LOOPS               |                          |     4 |   144 |     5   (0)| 00:00:01 |
|   3 |    TABLE ACCESS STORAGE FULL | STATE_MASTER             |     2 |    30 |     3   (0)| 00:00:01 |
|*  4 |    INDEX RANGE SCAN          | SYS166533_166534_RID_IDX |     2 |       |     0   (0)| 00:00:01 |
|   5 |   TABLE ACCESS BY INDEX ROWID| STATE_MASTER_XT          |     2 |    42 |     1   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   4 - access("T".ROWID="SYS_SXI_1"."RID")
SQL>
SQL>
SQL>
SQL>
SQL> select t.id, x.state_name
  2  from state_master t
  3     , xmltable('/ROOT/ROW' passing t.xml_state_name
  4         columns lang_id    number         path '@LANG_ID'
  5               , state_name varchar2(4000) path '.'
  6       ) x
  7  where x.lang_id = 1
  8  ;
  ID STATE_NAME
   1 Hello
   2 Goodbye
Execution Plan
Plan hash value: 1089002068
| Id  | Operation                    | Name                      | Rows  | Bytes | Cost (%CPU)| Time  |
|   0 | SELECT STATEMENT             |                           |     2 |    72 |     4   (0)| 00:00:01 |
|   1 |  NESTED LOOPS                |                           |     2 |    72 |     4   (0)| 00:00:01 |
|   2 |   TABLE ACCESS BY INDEX ROWID| STATE_MASTER_XT           |     2 |    42 |     2   (0)| 00:00:01 |
|*  3 |    INDEX RANGE SCAN          | STATE_MASTER_XT_LANG_ID_I |     2 |       |     1   (0)| 00:00:01 |
|   4 |   TABLE ACCESS BY USER ROWID | STATE_MASTER              |     1 |    15 |     1   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   3 - access("SYS_SXI_1"."LANG_ID"=1)