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查询v$archived_log时，发现BLOCK_SIZE的大小和数据库的块大小不一样：

SQL> select SEQUENCE#, BLOCKS, BLOCK_SIZE, to_char(COMPLETION_TIME, 'yyyy-mm-dd hh24:mi:ss') from v$archived_log order by COMPLETION_TIME;

SEQUENCE#     BLOCKS BLOCK_SIZE TO_CHAR(COMPLETION_
---------- ---------- ---------- -------------------
     1 65425          512 2012-11-06 18:12:54
     2 4284 512 2012-11-07 09:51:02
     3 583 512 2012-11-12 15:12:58

SQL> show parameter db_block_size

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_block_size integer 8192

这是因为redolog的块大小和数据文件不一致。

使用dbfsize命令可以查看文件的块大小

[oracle@test orcl]$ dbfsize control01.ctl
Database file: control01.ctl
Database file type: file system
Database file size: 430 16384 byte blocks

[oracle@test orcl]$ dbfsize sysaux01.dbf
Database file: sysaux01.dbf
Database file type: file system
Database file size: 29440 8192 byte blocks

[oracle@test orcl]$ dbfsize temp01.dbf
Database file: temp01.dbf
Database file type: file system
Database file size: 2560 8192 byte blocks

[oracle@test orcl]$ dbfsize redo01.log
Database file: redo01.log
Database file type: file system
Database file size: 102400 512 byte blocks

通过上面命令可以观察到，控制文件和redolog采用的单独的块大小。

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v$archived_log中的block_size

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