转储B*Tree索引的分枝结构！

转储索引结构：

SQL> select i.index_name,i.table_name,i.blevel from user_indexes i where i.index_name = 'IDX_T1_ID';INDEX_NAME                     TABLE_NAME                         BLEVEL------------------------------ ------------------------------ ----------IDX_T1_ID                      T1                                      2SQL> select object_id from dba_objects where object_name='IDX_T1_ID'; OBJECT_ID----------     73821SQL> alter session set events 'immediate trace name treedump level 73821';会话已更改。SQL> SQL> SQL> select d.value || '/' || lower(rtrim(i.instance, chr(0))) || '_ora_' ||  2         p.spid || '.trc' trace_file_name  3    from (select p.spid  4            from v$mystat m, v$session s, v$process p  5           where m.statistic# = 1  6             and s.sid = m.sid  7             and p.addr = s.paddr) p,  8         (select t.instance  9            from v$thread t, v$parameter v 10           where v.name = 'thread' 11             and (v.value = 0 or t.thread# = to_number(v.value))) i, 12         (select value from v$parameter where name = 'user_dump_dest') d;TRACE_FILE_NAME--------------------------------------------------------------------------------/u01/app/diag/rdbms/orcl/orcl/trace/orcl_ora_6255.trc

下面是trace文件：

----- begin tree dump*** 2012-06-28 00:58:43.036branch: 0x10001d3 16777683 (0: nrow: 9, level: 2)         --nrow: 9 表示下面有9个branch；level: 2 表示Index的高度为3。   branch: 0x1009b56 16816982 (-1: nrow: 578, level: 1)   --nrow: 578 表示有578个leaf。      leaf: 0x10001d4 16777684 (-1: nrow: 512 rrow: 221)  --rrow: 221 表示每个叶子包含221行。      leaf: 0x10001d5 16777685 (0: nrow: 512 rrow: 221)      leaf: 0x10001d6 16777686 (1: nrow: 512 rrow: 221)      ... ...   branch: 0x1009d79 16817529 (0: nrow: 538, level: 1)      leaf: 0x1009b55 16816981 (-1: nrow: 478 rrow: 224)      leaf: 0x1009b57 16816983 (0: nrow: 478 rrow: 223)      leaf: 0x1009b58 16816984 (1: nrow: 478 rrow: 222)      ... ...   branch: 0x1009f9d 16818077 (1: nrow: 537, level: 1)      leaf: 0x1009d78 16817528 (-1: nrow: 448 rrow: 210)      leaf: 0x1009d7a 16817530 (0: nrow: 450 rrow: 210)      leaf: 0x1009d7b 16817531 (1: nrow: 448 rrow: 210)      ... ...   branch: 0x100a1bf 16818623 (2: nrow: 537, level: 1)      leaf: 0x1009f9c 16818076 (-1: nrow: 448 rrow: 208)      leaf: 0x1009f9e 16818078 (0: nrow: 448 rrow: 208)      leaf: 0x1009f9f 16818079 (1: nrow: 448 rrow: 208)      ... ...   branch: 0x100a3e4 16819172 (3: nrow: 540, level: 1)      leaf: 0x100a1be 16818622 (-1: nrow: 448 rrow: 209)      leaf: 0x100a1c0 16818624 (0: nrow: 448 rrow: 210)      leaf: 0x100a1c1 16818625 (1: nrow: 448 rrow: 210)      ... ...   branch: 0x100a60a 16819722 (4: nrow: 539, level: 1)      leaf: 0x100a3e3 16819171 (-1: nrow: 450 rrow: 210)      leaf: 0x100a3e5 16819173 (0: nrow: 448 rrow: 210)      leaf: 0x100a3e6 16819174 (1: nrow: 448 rrow: 208)      ... ...   branch: 0x100a82b 16820267 (5: nrow: 536, level: 1)      leaf: 0x100a609 16819721 (-1: nrow: 448 rrow: 208)      leaf: 0x100a60b 16819723 (0: nrow: 448 rrow: 209)      leaf: 0x100a60c 16819724 (1: nrow: 448 rrow: 210)      ... ...   branch: 0x100aa4c 16820812 (6: nrow: 536, level: 1)      leaf: 0x100a82a 16820266 (-1: nrow: 448 rrow: 209)      leaf: 0x100a82c 16820268 (0: nrow: 448 rrow: 210)      leaf: 0x100a82d 16820269 (1: nrow: 449 rrow: 210)      ... ...   branch: 0x100abfe 16821246 (7: nrow: 428, level: 1)      leaf: 0x100aa4b 16820811 (-1: nrow: 448 rrow: 210)      leaf: 0x100aa4d 16820813 (0: nrow: 448 rrow: 210)      leaf: 0x100aa4e 16820814 (1: nrow: 450 rrow: 210)      ... ...----- end tree dump