起因：
trgt 开始在 catalog 注册使用过一段时间;
trgt 没有连接catalog，使用控制文件做了databse resetlog ; 控制文件中记录了两个incarnation;
再次使用catalog连接时，list incarnation; 只显示较早的incartion;
如果RMAN> resync catalog;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of resync command on default channel at 01/17/2010 10:06:53
RMAN-20003: target database incarnation not found in recovery catalog

RMAN> register database;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of register command on default channel at 01/17/2010 10:07:17
RMAN-20002: target database already registered in recovery catalog

解决方法：
RMAN> reset database;

new incarnation of database registered in recovery catalog
starting full resync of recovery catalog
full resync complete

RMAN> list incarnation;

List of Database Incarnations
DB Key Inc Key DB Name DB ID CUR Reset SCN Reset Time
------- ------- -------- ---------------- --- ---------- ----------
1 2 ORCL 1234192952 NO 1 24-DEC-09
1 62 ORCL 1234192952 YES 665802 13-JAN-10