domain index is marked LOADING/FAILED/UNUSABLE

domain index is marked LOADING/FAILED/UNUSABLE

Replicate the error
CREATE TABLE my_docs (
   id    NUMBER(10)     NOT NULL,
   name  VARCHAR2(200)  NOT NULL,
   doc   BLOB           NOT NULL
 );


 ALTER TABLE my_docs ADD (
   CONSTRAINT my_docs_pk PRIMARY KEY (id)
 );


 CREATE SEQUENCE my_docs_seq;


 CREATE OR REPLACE DIRECTORY documents AS 'C:\work';


 CREATE OR REPLACE PROCEDURE load_file_to_my_docs (p_file_name  IN  my_docs.name%TYPE) AS
   v_bfile      BFILE;
   v_blob       BLOB;
 BEGIN
   INSERT INTO my_docs (id, name, doc)
   VALUES (my_docs_seq.NEXTVAL, p_file_name, empty_blob())
   RETURN doc INTO v_blob;

   v_bfile := BFILENAME('DOCUMENTS', p_file_name);
   Dbms_Lob.Fileopen(v_bfile, Dbms_Lob.File_Readonly);
   Dbms_Lob.Loadfromfile(v_blob, v_bfile, Dbms_Lob.Getlength(v_bfile));
   Dbms_Lob.Fileclose(v_bfile);

   COMMIT;
 END;
 /



create index idx_domain on my_docs(doc) indextype is ctxsys.context parameters ('sync (on commit)');

Now Rebuild the index "idx_domain" to replicate the error , on same time i execute below command and it throws error:

SQL>  EXEC load_file_to_my_docs('try.pdf');
BEGIN load_file_to_my_docs('try.pdf'); END;

*
ERROR at line 1:
ORA-29861: domain index is marked LOADING/FAILED/UNUSABLE
ORA-06512: at "G.LOAD_FILE_TO_MY_DOCS", line 5
ORA-06512: at line 1

Solution::
Rebuilds Domain index/ full text index as below:::
 
ALTER INDEX your_index REBUILD ONLINE PARAMETERS ('REPLACE LEXER your_lexer');