How to create an index for bi-lingual text column

Question

I have a column that keeps the full file name of the attachment document file of a record. I need to build an index on the column so that we can search the attachment document file. The content of the file will be in English or French, but we don't know which one is in English and which one is in French. How I should build the index so that it will support 'contains' query and 'about' query for both English and French documents? What lexer, wordlist and stoplist I should use?
Here is something I am thinking:
lexer: basic_lexer
stoplist: build a custom stoplist that contains the stopwords for English and French.
wordlist: use the default for US should be OK since we don't need to support fuzzy and stem search.
The only problem is that it will only create the theme index properly for the English document but not the French document. This is because the NLS_LANG setting for the session is always in English. Therefore, the English knowledge base and lexicon will be used. I cannot use the THEME_LANGUAGE setting to overide it because I don't know the language of the document. Is there a way to merge the English knowleage base and lexicon with the French ones so that we can create a correct theme index without knowing the language of the document?
I am also thinking about using the multi_lexer. However, it won't help since we don't the language of the document.
Can anyone give me some help?
Thanks,
Wenjie
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Answer 1

Creating a primary key, by definition, creates a (unique) index. Either inline at table creation, or via an alter table.
If its a composite PK, the alter table or inline constraint definition, after all the column declarations, is the only way to do it that I'm aware of.
create table t1 ( t1_pk number,
   t1_desc varchar2(50),
   constraint primary key t1_name_pk (t1_pk) [ using index tablespace <tblspc>]
-- or can constrain at the column def
create table t1 ( t1_pk number constraint t1_name_pk primary key ...,
-- or with an alter table. this won't work if there are non-unique entries
alter table t1 add ( constraint t1_name_pk primary key ( t1_pk [ index clause ] );The t1_name_pk constraint name can be optional, but if you don't include a constraint name the error messages are difficult to interpret, you get a system generated constraint name.
"... constraint <schema.>t1_name_pk violated ... " is much more informative than "... constraint <schema.>SYS_CNNNNNNNN violated ...".
The created index gets the same name used for the constraint as well.