ORA-01555错误浅析(2)

核心提示： data_block_dump,data header at 0x7505664===tsiz: 0x1f98hsiz: 0x18pbl: 0x07505664bdba: 0x0140c70f76543210flag=ntab=1nrow=3frre=-1fsbo=0x18fseo=0x1

data_block_dump,data header at 0x7505664

===============

tsiz: 0x1f98

hsiz: 0x18

pbl: 0x07505664

bdba: 0x0140c70f

76543210

flag=--------

ntab=1

nrow=3

frre=-1

fsbo=0x18

fseo=0x1f4a

avsp=0x1f62

tosp=0x1f62

0xe:pti[0] nrow=3 offs=0

0x12:pri[0] offs=0x1f5e

0x14:pri[1] offs=0x1f4a

0x16:pri[2] offs=0x1f54

block_row_dump:

tab 0, row 0, @0x1f5e

tl: 10 fb: --H-FL-- lb: 0x1 cc: 2

col 0: [ 2] c1 02

col 1: [ 3] c2 02 10

tab 0, row 1, @0x1f4a

tl: 10 fb: --H-FL-- lb: 0x0 cc: 2

col 0: [ 2] c1 03

col 1: [ 3] c2 03 17

tab 0, row 2, @0x1f54

tl: 10 fb: --H-FL-- lb: 0x0 cc: 2

col 0: [ 2] c1 04

col 1: [ 3] c2 03 17

end_of_block_dump

End dump data blocks tsn: 5 file#: 5 minblk 50959 maxblk 50959

其余的内容在我们讨论的这个问题中不需要太关心，主要注意红色黑体部分和Interested Transaction Slot (ITS) 部分。

CSC:即Cleanout SCN，它是在我们的insert操作事务中产生的。

Flag：事务标志位。由于我们在提交之前将buffer cache手动flush了，所以标志位为空。请注意到，我们这在commit之前DBwn已经写回了脏数据，标志为空。各个标志的含义分别是：

C--- = transaction has been committed and locks cleaned out

-B-- = this undo record contains the undo for this ITL entry

--U- = transaction committed (maybe long ago); SCN is an upper bound