create table EVENT (
    UUID raw(16) default sys_guid(),  -- no significant for question
    TYPE number(2,0) not null,
    DATEX date not null,
    AMOUNT number(18,2) -- we use op: SUM, COUNT, AVG, STDDEV_POP, MEDIAN, etc
);

create index INDEX_EVENT_MAIN on EVENT (TYPE ASC, DATEX ASC);

alter table EVENT add partition event_default values (DEFAULT);

alter table DATA_XX split partition event_default values(2) into (
  partition event2,
  partition event_default);

select id, one_column, another_column
  from two_hundred_mb_table
 where id = 1

select sum(one_column) / sum(another_column)
  from two_hundred_mb_table

--Blocks read per multi-block read, if you set the value yourself.
select value from v$parameter where name = 'db_file_multiblock_read_count';

--Time to read single and multiple blocks, in milliseconds.
--And average blocks per multi-block read.
select * from sys.aux_stats$ where pname in ('SREADTIM', 'MREADTIM', 'MBRC');