oracle表空间自动扩展大小 - 数据库编程

select a.FILE_NAME,a.AUTOEXTENSIBLE,a.MAXBYTES,a.INCREMENT_BY from dba_data_files a;

--AUTOEXTENSIBLE 是否自动扩展

--MAXBYTES 最大
--INCREMENT_BY 自动扩展块数

SQL> show parameter db_block

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_block_buffers integer 0
db_block_checking boolean FALSE
db_block_checksum boolean TRUE
db_block_size integer 8192

--db_block_size*INCREMENT_BY 块大小*块数=自动扩展的大小;

例:
create tablespace sq01 datafile 'd:\sq01.bdf' size 5m ; --创建表空间

alter database datafile 'd:\sq01.bdf' autoextend on next 20m maxsize 100m;
-- 修改表空间自动增长每次增长20m最大空间100M

SQL> select a.FILE_NAME,a.AUTOEXTENSIBLE,a.MAXBYTES,a.INCREMENT_BY from dba_data_files a ;

FILE_NAME AUTOEXTENSIBLE MAXBYTES INCREMENT_BY
-------------------------------------------------------------------------------- -------------- ---------- ------------
D:\SQ01.BDF YES 104857600 2560

SQL> show parameter db_block

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_block_buffers integer 0
db_block_checking boolean FALSE
db_block_checksum boolean TRUE
db_block_size integer 8192

SQL> select 2560*8192/1024/1024||'M' from dual;

2560*8192/1024/1024||'M'
------------------------

20M