select * from index_stats;

create table t_objects as select * from all_objects;

–1.索引不压缩

create index t_objects_idx on t_objects(owner,object_type,object_name);

analyze index t_objects_idx validate structure;

create table idx_stats as
select ‘noncompressed’ as type,a.* from index_stats a;

–2.索引压缩第1列
drop index t_objects_idx;
create index t_objects_idx on t_objects(owner,object_type,object_name) compress 1;
analyze index t_objects_idx validate structure;

insert into idx_stats
select ‘compressed 1’,a.* from index_stats a;
commit;
–2.索引压缩前2列
drop index t_objects_idx;
create index t_objects_idx on t_objects(owner,object_type,object_name) compress 2;
analyze index t_objects_idx validate structure;

insert into idx_stats
select ‘compressed 2’,a.* from index_stats a;
commit;
–3.索引压缩3列
drop index t_objects_idx;
create index t_objects_idx on t_objects(owner,object_type,object_name) compress 3;
analyze index t_objects_idx validate structure;

insert into idx_stats
select ‘compressed 3’,a.* from index_stats a;
commit;

–4.索引压缩1列
drop index t_objects_idx;
create index t_objects_idx on t_objects(object_type,owner,object_name) compress 1;
analyze index t_objects_idx validate structure;

insert into idx_stats
select ‘compressed a1’,a.* from index_stats a;
commit;

select * from idx_stats;