Oracle10g 控制文件的改变

前几天说过，Oracle10g Events CONTROLF的改变，当时猜测控制文件的变化可能是为了满足Oracle10g Grid运算支持大量并行实例的需要。

单实例节点控制文件转储包含的位图如下:

Database checkpoint: Thread=1 scn: 0x0000.0007276a

Threads: #Enabled=1, #Open=1, Head=1, Tail=1

enabled threads: 01000000 00000000 00000000 00000000 00000000 00000000

00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

今天转储了一个RAC数据库的控制文件，验证了这个猜测：

***************************************************************************

DATABASE ENTRY

***************************************************************************

(size = 316, compat size = 316, section max = 1, section in-use = 1,

last-recid= 0, old-recno = 0, last-recno = 0)

(extent = 1, blkno = 1, numrecs = 1)

12/27/2006 16:25:27

DB Name "EYGLE"

Database flags = 0x00404000 0x00001000

Controlfile Creation Timestamp 12/27/2006 16:25:30

Incmplt recovery scn: 0x0000.00000000

Resetlogs scn: 0x0000.00000001 Resetlogs Timestamp 12/27/2006 16:25:27

Prior resetlogs scn: 0x0000.00000000 Prior resetlogs Timestamp 01/01/1988 00:00:00

Redo Version: compatible=0xa200100

#Data files = 5, #Online files = 5

Database checkpoint: Thread=2 scn: 0x0000.008a8531

Threads: #Enabled=2, #Open=2, Head=2, Tail=1

enabled threads: 01100000 00000000 00000000 00000000 00000000 00000000

00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

Oracle不断的将位图引入数据库的各个治理单元，显然旨在性能提高。

-The End-

http://www.eygle.com/archives/2007/02/controlfile_bitmap.Html