A Simple Experiment for Oracle Transaction

Yong Huang

最初由 Puber 发布
[B]create or replace procedure show_rowid
( pi_rowid_in      in  varchar2)
...
I have not tested in Oracle 10g.
It is not important that where the data  is.
Hope you are able to find them by upper procedure. [/B]

I know the point of your research is finding the transaction mechanism, not where the data exists. I also know how your show_rowid procedure works even if you don't show the code here. I'm just curious about something you alluded to in the passing (i.e. in 9i, the data resides in the middle of the extent instead of after pagetable header block).

Yong Huang

Puber

This question confuses me too.
I can not explain it.

BTW: The 'TOOLS' tablespace has ever been used. All segments on it were dropped before the experiment.

select owner,segment_name,segment_type,tablespace_name,extent_id,file_id,block_id,blocks,relative_fno from dba_extents where tablespace_name='TOOLS';
OWNER    SEGMENT_NA SEGMENT_ TABLESPACE EXTENT_ID FILE_ID BLOCK_ID BLOCKS RELATIVE_FNO
-------- ---------- -------- ---------- --------- ------- -------- ------ ------------
SYS      DEMOTAB    TABLE    TOOLS              0       4        9      8            4


select object_name,createD from dba_objects where object_name in ('DEMOTAB','ZNTEST');

OBJECT_NAME                              CREATED
---------------------------------------- -----------------
DEMOTAB                                  20050115 15:11:47

Fenng

怎么没看到红颜色的字?

Puber

最初由 Fenng 发布
[B]怎么没看到红颜色的字? [/B]

这个.这个...

去偶的blog看吧.

http://blog.itpub.net/puber

或看附件.

Yong Huang

最初由 Puber 发布
[B]...
BTW: The 'TOOLS' tablespace has ever been used. All segments on it were dropped before the experiment.

select owner,segment_name,segment_type,tablespace_name,extent_id,file_id,block_id,blocks,relative_fno from dba_extents where tablespace_name='TOOLS';
OWNER    SEGMENT_NA SEGMENT_ TABLESPACE EXTENT_ID FILE_ID BLOCK_ID BLOCKS RELATIVE_FNO
-------- ---------- -------- ---------- --------- ------- -------- ------ ------------
SYS      DEMOTAB    TABLE    TOOLS              0       4        9      8            4
...
[/B]

Are you saying TOOLS was never used or it *was* used at some point of time? But I don't think it matters.

Thanks for telling us the number of blocks in the extent. Since the starting block is 9 and blocks is 8 and your data is in block 15, it looks like the data is in kind of in the middle of the second half of the extent. Mine is too (BTW, earlier I said my data was in the first block of the second half. I was wrong. I just edited and changed my message saying it's near the middle of the second half). I don't know how to explain.

Yong Huang

Puber

"The 'TOOLS' tablespace has ever been used.All segments on it were dropped before the experiment."

这句话的意思偶应该没译错吧!

TOOLS表空间曾经被使用过,但在开始实验之前其中所有的segment都被drop了.


偶的E文菜的说,见谅了!

但还是坚持用的说!

Puber

做这个实验另一个主要原因是,看了这个贴了http://www.itpub.net/showthread.php?threadid=131231&pagenumber=
,对里面提到的很多名专用名词不熟.
于是dump出来对应一下.

而现在那个贴子的内容还是没有全想通.