--查看表的创建时间
select created,last_ddl_time from dba_objects where owner='USER_FY' and object_name='YHGL';
--查看表的大小
1)select segment_name 表名,to_char(sum(bytes)/1024/1024/1024,'999G999D999')||'G' 所占空间
from dba_segments where owner='USER_FY' and segment_name='TEST1'group by segment_name;
2)select to_char(sum(bytes)/1024/1024,'999G999D999')||'M' from dba_segments where owner='USER_FY' and segment_name='TEST1';
--查看表所占空间
select tablespace_name 表空间名称,to_char(sum(bytes)/(1024*1024*1024),'999G999D999')||'G' 表所占空间
from dba_extents where owner='&owner' and segment_name='&table_name' and segment_type like 'TABLE%'group by tablespace_name;
注释：有两种含义的表大小
1）一种是分配给一个表的物理空间数量，而不管空间是否被使用，可以这样查询获得字节数：
select segment_name, bytes from user_segments where segment_type = 'TABLE' and segment_name='TEST1';
select segment_name, bytes from user_segments where segment_type = 'INDEX';
或者
select segment_name,sum(bytes)/1024/1024 from user_extents group by segment_name;
2)另一种表实际使用的空间，这样查询：
analyze table test1 compute statistics;
select num_rows *avg_row_len from user_tables where table_name='TEST1';
--查看每个表空间的大小
select tablespace_name 表空间名称,sum(bytes)/1024/1024||'M' 所占空间 from dba_segments group by tablespace_name;
