SQL> conn tc/tc@localhost/pdb
Connected.
SQL>
SQL> set echo on serverout on
SQL>
SQL> !oerr ora 22836
22836, 00000, "Event to turn on lob to char/raw silent truncation"
// *Document: NO
// *Cause:    N/A
// *Action:   Do not throw error 22835 for truncation during LOB to CHAR/RAW
//            conversion. Truncate the data instead.

SQL>
SQL> drop table t;

Table dropped.

SQL>
SQL> create table t(vc varchar2(4000));

Table created.

SQL>
SQL> var c clob
SQL>
SQL> begin
  2    select xmltype.createxml(cursor(select * from all_objects)).getClobVal()
  3      into :c
  4      from dual;
  5  end;
  6  /

PL/SQL procedure successfully completed.

SQL>
SQL> exec dbms_output.put_line(dbms_lob.getlength(:c))
12273513

PL/SQL procedure successfully completed.

SQL>
SQL> insert into t values (to_char(:c));
insert into t values (to_char(:c))
                      *
ERROR at line 1:
ORA-22835: Buffer too small for CLOB to CHAR or BLOB to RAW conversion (actual:
12273513, maximum: 4000)


SQL>
SQL> alter session set events '22836 level 1';

Session altered.

SQL>
SQL> insert into t values (to_char(:c));

1 row created.

SQL>
SQL> select length(vc) from t;

LENGTH(VC)
----------
      4000

SQL>
SQL> select banner_full from v$version;

BANNER_FULL
--------------------------------------------------------------------------------
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.9.0.0.0

SQL> alter system set events '22836 level 1';

System altered.

SQL> oradebug setmypid
Statement processed.
SQL> oradebug eventdump system
22836 level 1
SQL> startup force
ORACLE instance started.

Total System Global Area 2113927808 bytes
Fixed Size                  9136768 bytes
Variable Size            1325400064 bytes
Database Buffers          771751936 bytes
Redo Buffers                7639040 bytes
Database mounted.
Database opened.
SQL> oradebug setmypid
Statement processed.
SQL> oradebug eventdump system
Statement processed.
SQL> alter system set event='22836 level 1' scope=spfile;

System altered.

SQL> startup force
ORACLE instance started.

Total System Global Area 2113927808 bytes
Fixed Size                  9136768 bytes
Variable Size            1325400064 bytes
Database Buffers          771751936 bytes
Redo Buffers                7639040 bytes
Database mounted.
Database opened.
SQL> oradebug setmypid
Statement processed.
SQL> oradebug eventdump system
22836 level 1