hi Tom,
when a remote table is referred in sub query then it is not retrieving the data and it throws error.

refer the below sql, I am trying to get latest record, so I am doing order by DATEM in sub query and taking first record in outer sql. here, OWNERDOCUMENTS used in FROM clause is a synonym created for a remote table.

The below sql not working!

select ownercode,img_path_back,img_path_front,DELETED_FLG,useridm,DATEM  
FROM ( select ownercode,img_path_back,img_path_front,customer_name,NVL(DELETED_FLG,'N')  DELETED_FLG,useridm,DATEM 
    from OWNERDOCUMENTS where OWNERCODE=NVl('xxxx',OWNERCODE)  Order By DATEM DESC ) WHERE  ROWNUM=1;

The sql below is working!!

select ownercode,img_path_back,img_path_front,customer_name,NVL(DELETED_FLG,'N')  DELETED_FLG,useridm,DATEM 
    from OWNERDOCUMENTS where OWNERCODE=NVl('xxxx',OWNERCODE)  Order By DATEM DESC;

what could be the issue? please advice.