SELECT segment_name AS TABLENAME,round(BYTES/1024/1024,2) FROM user_segments WHERE segment_name=\'表名\'。 查出来的是M为单位；
select tt1.table_name,
tt1.length1,
tt2.rownums,
round(tt1.length1 * tt2.colnum * tt2.rownums / 1024 / 1024, 2) as sum_MB
from (select t.table_name, sum(t.DATA_LENGTH) as length1
from dba_tab_columns t, ecp_temp t1
where t.owner = \'BIDPRO\'
and t.table_name = t1.tablename
group by t.table_name) tt1,
ecp_temp tt2
where tt1.table_name = tt2.tablename;