比较深入看过dba_extents视图的朋友都知道,它得到extent的信息不是通过普通的存储在数据库中的基表获得,而是x$相关的表获得(x$表是数据库启动时候在内存中创建,不存在数据文件中),因为当数据库未正常启动,我们无法直接确定某个block是否在某个对象中.其实关于extent的信息都已经记录在了segment header的block中,通过dump该block记录的rdba信息,未转化为file_id和block_id,这里写shell脚本实现把segment header dump 内容转化为类似dba_extents记录,方便在某些不能open的库中分析某个异常block是否属于某个表
#! /bin/bash
dec2bin(){
val_16=$1
((num=$val_16));
val=`echo $num`
local base=$2
[ $val -eq 0 ] && bin=0
if [ $val -ge $base ]; then
dec2bin $val $((base*2))
if [ $val -ge $base ]; then
val=$(($val-$base))
bin=${bin}1
else
bin=${bin}0
fi
fi
[ $base -eq 1 ] && printf $bin
}
for i in `grep "length:" $1 |awk '{print $1 $3}'`;
do
rdba=`echo ${i:0:10}`
blocks=`echo ${i:10}`
echo -n "rdba:"$rdba" "
bin2=`dec2bin $rdba 1`
len=`expr length $bin2`
len_gd=22
len_jg=`expr $len - $len_gd`
file_no_2=`echo ${bin2:0:$len_jg}`
((file_no=2#$file_no_2))
echo -n "file_id:"$file_no" "
block_no_2=`echo ${bin2:$len_jg}`
((block_no=2#$block_no_2))
echo -n "block_id:"$block_no" "
echo "blocks:"$blocks
done;
trace文件中部分信息
----------------------------------------------------------------- 0x00400901 length: 7 0x00402e10 length: 8 0x00402e60 length: 8 0x00402e68 length: 8 0x00402ea0 length: 8 0x00402f20 length: 8 0x00402f48 length: 8 0x00403050 length: 8 0x00403180 length: 8 0x00403b38 length: 8 0x00404c48 length: 8 0x00404c78 length: 8 0x00404cf8 length: 8 0x00404da8 length: 8 0x00404db8 length: 8 0x00404de8 length: 8 0x00404e80 length: 128 0x00405900 length: 128 0x00406500 length: 128 0x00406980 length: 128 0x00407480 length: 128 0x00407500 length: 128 0x00407680 length: 128 0x00407800 length: 128 0x00407880 length: 128 0x00407a00 length: 128 0x00407a80 length: 128 0x00407c80 length: 128 …………
执行结果
[oracle@xifenfei tmp]$ ./get_extent.sh /u01/app/oracle/diag/rdbms/cdb/cdb/trace/cdb_ora_29565.trc rdba:0x00400901 file_id:1 block_id:2305 blocks:7 rdba:0x00402e10 file_id:1 block_id:11792 blocks:8 rdba:0x00402e60 file_id:1 block_id:11872 blocks:8 rdba:0x00402e68 file_id:1 block_id:11880 blocks:8 rdba:0x00402ea0 file_id:1 block_id:11936 blocks:8 rdba:0x00402f20 file_id:1 block_id:12064 blocks:8 rdba:0x00402f48 file_id:1 block_id:12104 blocks:8 rdba:0x00403050 file_id:1 block_id:12368 blocks:8 rdba:0x00403180 file_id:1 block_id:12672 blocks:8 rdba:0x00403b38 file_id:1 block_id:15160 blocks:8 rdba:0x00404c48 file_id:1 block_id:19528 blocks:8 rdba:0x00404c78 file_id:1 block_id:19576 blocks:8 rdba:0x00404cf8 file_id:1 block_id:19704 blocks:8 rdba:0x00404da8 file_id:1 block_id:19880 blocks:8 rdba:0x00404db8 file_id:1 block_id:19896 blocks:8 rdba:0x00404de8 file_id:1 block_id:19944 blocks:8 rdba:0x00404e80 file_id:1 block_id:20096 blocks:128 rdba:0x00405900 file_id:1 block_id:22784 blocks:128 rdba:0x00406500 file_id:1 block_id:25856 blocks:128 rdba:0x00406980 file_id:1 block_id:27008 blocks:128 rdba:0x00407480 file_id:1 block_id:29824 blocks:128 rdba:0x00407500 file_id:1 block_id:29952 blocks:128 rdba:0x00407680 file_id:1 block_id:30336 blocks:128 rdba:0x00407800 file_id:1 block_id:30720 blocks:128 …………
