oracle 查看某张表占用空间大小的SQL语句怎么写?

Answer 1

select t.segment_name, t.segment_type, sum(t.bytes / 1024 / 1024) "占用空间(M)"
from dba_segments t
where t.segment_type='TABLE'
and t.segment_name='表名大写'
group by OWNER, t.segment_name, t.segment_type;

Answer 2

select num_rows * avg_row_len/1024/1024
from user_tables
where table_name = EMP;--EMP为表名（表名大写查询）