How to find an text in entire Oracle database?
See https://lalitkumarb.wordpress.com/2015/01/06/sql-to-search-for-a-value-in-all-columns-of-all-atbles-in-an-entire-schema. In short (with my slightly modified version of the code):

SELECT DISTINCT table_name, column_name
  FROM user_tab_cols,
  TABLE (xmlsequence (dbms_xmlgen.getxmltype ('select '
  || column_name
  || ' from '
  || table_name
  || ' where upper('
  || column_name
  || ') like upper(''%'
  || '&amp;searchword'
  || '%'')' ).extract ('ROWSET/ROW/*') ) ) t
  where table_name not in (
    select distinct table_name
      from user_tab_cols where data_type like 'SDO%'
      or data_type like '%LOB')
  order by table_name, column_name;


I exclude tables that contain LOB or spatial columns as they can fail. Add other filters as you please. This will be very expensive to run in a large database!

EDIT: &amp;searchword is the text you are searching for, of course.