SQL optimization Chapter VIII Case analog 8.2 max min while reading optimization

This case reference "SQL optimization core idea" (Luobing Sen, Huang Chao Zhong Jiao forward).

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8.2.1 configuration data environment

drop table test1;

create table test1 as select * from dba_objects;

create index ix_test1_01 on test1(object_id);

8.2.2 SQL problem

select min(t1.object_id),max(t1.object_id) from test1 t1;

8.2.3 rewrite optimization

select min(id) as min_id,max(id) as max_id from 

(select min(t1.object_id) as id from test1 t1

union all

select max(t1.object_id)  from test1 t1);