下次如果再遇到，请记录下会话的等待事件，是否存在blocking session，以及完整的10046报告。

这里是保留的跟踪文件， oradebug 跟踪的是cbc热点块 ，能否进一步缩小范围呢

你提供的3个trace都很快完成了，没有任何问题啊。夯住的话基本上只有在同时执行，相互阻塞时才会出现。

如下是加字段trace的TKPROF结果, 第4列是elapsed，用时非常短，额外的只是多了OGG的ddl trigger

[oracle@uz steven]$ cat alter_add_column1004.txt|grep total
total       23      0.00       0.00          0         41          0           8
total        6      0.00       0.00          0          2          0           2
total        9      0.00       0.00          0         16          0           4
total       12      0.01       0.00          0         21          0           3
total       11      0.00       0.00          0         14          0           4
total       44      0.00       0.00          0         12          0          35
total        9      0.00       0.00          0         12          0           4
total       13      0.00       0.01          1         18          0           6
total        7      0.00       0.00          0          9          0           3
total        2      0.01       0.01          1          1          0           0
total        2      0.00       0.01          3          3          3           0
total        3      0.00       0.00          0          2          0           0
total        3      0.00       0.00          0          2          0           0
total        2      0.00       0.00          0          0          0           1
total        6      0.01       0.00          0          0          0           2
total        6      0.00       0.00          0          0          0           2
total        6      0.00       0.00          0          0          0           2
total        3      0.00       0.00          0          0          0           1
total        6      0.00       0.00          0          0          0           2
total        6      0.00       0.00          0          0          0           2
total        5      0.00       0.04          3          8          0           2
total        4      0.00       0.02          2          5          0           1
total        4      0.00       0.00          2          5          0           1
total        4      0.00       0.01          2          7          0           2
total        3      0.00       0.00          0          0          0           1
total        6      0.04       0.04          0         36          0           3
total        3      0.00       0.00          0          3          0           1
total        4      0.00       0.00          0          7          0           1
total        3      0.00       0.00          0          3          0           0
total       12      0.00       0.00          0          8          0           4
total        7      0.00       0.00          0          0          0           3
total        7      0.00       0.00          0          6          0           0
total        7      0.01       0.00          0          6          0           0
total        7      0.00       0.00          0          6          0           0
total        9      0.00       0.00          0         10          0           2
total        2      0.01       0.01          1          1          0           0
total        3      0.00       0.00          0          3          0           0
total        3      0.00       0.00          0          3          0           0
total        3      0.00       0.01          1          1          0           0
total        4      0.00       0.00          0          4          0           1
total        3      0.01       0.00          1          1          0           0
total       24      0.00       0.00          0          3          0          21
total        3      0.00       0.00          0          1          0           0
total        7      0.00       0.00          1          8          0           2
total        4      0.00       0.00          0          2          0           0
total        4      0.00       0.00          0          2          0           0
total        3      0.00       0.00          0          6          5           2
total        2      0.00       0.04          3          2         10           1
total        3      0.00       0.00          0          6          4           2
total        2      0.00       0.00          0          3         10           1
total        2      0.00       0.00          0          2          0           0
total        2      0.01       0.00          0          2          0           0
total        2      0.00       0.00          0          2          0           0
total        2      0.00       0.00          0          2          0           0
total        2      0.00       0.00          0          2          0           0
total        3      0.00       0.00          0          3          0           0
total        1      0.00       0.00          0          0          0           0
total        1      0.00       0.00          0          0          0           0
total        1      0.00       0.00          0          0          0           0
total        2      0.00       0.00          0          0          0           1
total        3      0.00       0.00          0          0          0           1
total        2      0.00       0.00          0          0          0           0
total        3      0.00       0.00          0          0          0           1
total        2      0.01       0.00          0          3          8           1
total        2      0.01       0.00          0          0          0           0
total        4      0.01       0.01          3          3          3           0
total      360      0.17       0.34         18        322         37         136

谢谢老师，下回出现问题我再全面抓跟踪记录