Pesquisar todas as colunas, todas as tabelas para um valor específico

CLEAR SCREEN
SET VERIFY OFF
ACCEPT val CHAR PROMPT 'What value do you want to search for: '
CLEAR SCREEN;

DECLARE
    match_count                             INTEGER;
    v_search_string                         VARCHAR2(4000) := '&val'; /* this was <<val>> */
BEGIN
    FOR t IN (SELECT owner,
                     table_name,
                     column_name
                FROM all_tab_columns
               WHERE data_type IN ('CHAR',
                                   'VARCHAR2',
                                   'NCHAR',
                                   'NVARCHAR2',
                                   'CLOB',
                                   'NCLOB')) 
    LOOP
        BEGIN
            EXECUTE IMMEDIATE 'SELECT COUNT(*) FROM ' || t.owner || '.' || t.table_name || ' WHERE ' || t.column_name || ' = :1' INTO match_count USING v_search_string;

            IF match_count > 0
            THEN
                DBMS_OUTPUT.put_line(t.owner || '.' || t.table_name || '     ' || t.column_name || ' ' || match_count);
            END IF;
        EXCEPTION
            WHEN OTHERS
            THEN
                DBMS_OUTPUT.put_line('Error encountered trying to read ' || t.column_name || ' from ' || t.owner || '.' || t.table_name);
        END;
    END LOOP; 
END;
/