[20211110]oracle数字编码30.txt

[20211110]oracle数字编码30.txt --//链接http://www.itpub.net/thread-2144556-1-1.html，出现数字编码30的问题，理论讲不可能出现这样的编码。 --//以前也遇到类似的问题。http://www.itpub.net/thread-2095697-1-1.html --//自己在测试环境模拟看看。 1.环境： SCOTT@book> @ ver1 PORT_STRING                    VERSION        BANNER ------------------------------ -------------- -------------------------------------------------------------------------------- x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production 2.测试: create table t ( x number); insert into t values (0); insert into t values (1); insert into t values (2); insert into t values (0); commit ; SCOTT@book> select rowid,t.* from t ; ROWID                    X ------------------ ------- AABQdgAAEAAAALDAAA       0 AABQdgAAEAAAALDAAB       1 AABQdgAAEAAAALDAAC       2 AABQdgAAEAAAALDAAD       0 SCOTT@book> @ rowid AABQdgAAEAAAALDAAA     OBJECT       FILE      BLOCK        ROW ROWID_DBA            DBA                  TEXT ---------- ---------- ---------- ---------- -------------------- -------------------- ----------------------------------------     329568          4        707          0  0x10002C3           4,707                alter system dump datafile 4 block 707 ; BBED> x /rx *kdbr[3] rowdata[0]                                  @8166 ---------- flag@8166: 0x2c (KDRHFL, KDRHFF, KDRHFH) lock@8167: 0x02 cols@8168:    1 col    0[1] @8169:  0x80 BBED> assign offset 8170=0x30; ub1 rowdata[0]                              @8170     0x30 --//注意偏移要加1，前面1位是长度指示器。 BBED> sum apply Check value for File 4, Block 707: current = 0xb731, required = 0xb731 BBED> x /rx *kdbr[3] rowdata[0]                                  @8166 ---------- flag@8166: 0x2c (KDRHFL, KDRHFF, KDRHFH) lock@8167: 0x02 cols@8168:    1 col    0[1] @8169:  0x30 3.在sqlplus下执行： SCOTT@book> select rowid,dump(x) c30 ,x from t ; ROWID              C30                                      X ------------------ ------------------------------ ----------- AABQdgAAEAAAALDAAA Typ=2 Len=1: 128                         0 AABQdgAAEAAAALDAAB Typ=2 Len=2: 193,2                       1 AABQdgAAEAAAALDAAC Typ=2 Len=2: 193,3                       2 AABQdgAAEAAAALDAAD Typ=2 Len=1: 48                ########### --//在toad下执行报如下错误。 OCI-22065: number to text translation for the given format causes overflow