[20130609]ORA_HASH and LOBs.txt
http://connormcdonald.wordpress.com/2013/03/29/ora_hash-and-lobs-not-nice-partners/
参考以上链接,重复测试:
create table t (a number,b varchar2(20),c clob);
insert into t values (1,'a','a');
commit ;
It changes ! In fact, one most platforms it appears to change every 3 seconds, so presumably somewhere in there its
related to one the internal Oracle timers in some way.
http://connormcdonald.wordpress.com/2013/03/29/ora_hash-and-lobs-not-nice-partners/
参考以上链接,重复测试:
create table t (a number,b varchar2(20),c clob);
insert into t values (1,'a','a');
commit ;
SQL> select ora_hash(b),ora_hash(c) from t;
ORA_HASH(B) ORA_HASH(C)
----------- -----------
29220167 2365849875
--sleep 3s
SQL> select ora_hash(b),ora_hash(c) from t;
ORA_HASH(B) ORA_HASH(C)
----------- -----------
29220167 892983579
--sleep 3s
SQL> select ora_hash(b),ora_hash(c) from t;
ORA_HASH(B) ORA_HASH(C)
----------- -----------
29220167 3168263238
It changes ! In fact, one most platforms it appears to change every 3 seconds, so presumably somewhere in there its
related to one the internal Oracle timers in some way.
