呵呵,楼主的回帖很有意思
raw是小的二进制对象,最大长度为2000字节
主要用来存贮一些小的文件
long raw看long 就知道了,最大长度为2GB
rowid是数据的物理地址
urowid 是"universal rowids"的意思
Oracle uses "universal rowids" (urowids) to store the addresses of index-organized
and foreign tables. Index-organized tables have logical urowids and foreign tables
have foreign urowids. Both types of urowid are stored in the ROWID pseudocolumn
(as are the physical rowids of heap-organized tables).