Recommended settings for a small table with high update rate
Oracle 12c: Simple test case: one session inserting 256 rows:

MARK.STEWART@dev01&gt; create table mytab (
    primary_key_column number,
    a number,
    b number,
    c number,
    d number,
    e number,
    f number
);

Table created.

MARK.STEWART@dev01&gt;   insert into mytab (select rownum, OBJECT_ID, DATA_OBJECT_ID, NAMESPACE, DBMS_RANDOM.VALUE(1, 256), DBMS_RANDOM.VALUE(1, 256),  DBMS_RANDOM.VALUE(1, 256) from dba_objects  where rownum &lt; 257);

256 rows created.

Elapsed: 00:00:00.77


Updated a row 1,000 times and committed after each update, took only 0.29 of a seconds:

MARK.STEWART@dev01&gt; begin
   2      for loop_var in 1 .. 1000 loop
   3              execute immediate 'update  mytab set a= 1 where PRIMARY_KEY_COLUMN = 6';
   4              execute immediate 'commit';
   5      end loop;
   6  end;
   7  /

PL/SQL procedure successfully completed.

Elapsed: 00:00:00.29
MARK.STEWART@dev01&gt;


With  pctfree 99 initrans 20 it took almost twice as long (probably due to having high value for initrans): 00:00:00.65