Hi!

I have a problem with XDB.XMLIndex. First of all, I create table:

CREATE TABLE DBF_LOG_TST (
  DBF_HEADER   CLOB,
  DBF_DATA     XMLTYPE
)
XMLType COLUMN DBF_DATA
        STORE AS BASICFILE CLOB
(TABLESPACE LOB
STORAGE (INITIAL 64 K
         MAXEXTENTS UNLIMITED));

then I create index

CREATE INDEX IDX_DBF_LOG_DocumentElement ON DBF_LOG_TST(DBF_DATA) 
  INDEXTYPE IS XDB.XMLIndex
  PARAMETERS ('paths (include (/DocumentElement/table))');

From application server, I send request with big xml data and save them into the table.
After that I select data from DBF_DATA field and some times get an error ORA-29861: domain index is marked LOADING/FAILED/UNUSABLE. Of couse at first I drop index with force key, then create again index or not drop index and only rebuild. But get this error again and again, onсe a week. Help please, for what reasons does this error occur?