Reference Link:
http://www.orafaq.com/forum/t/44492/0/

From which we can include the main difference is that

1.
Before ORACLE 8i whatever u create Snapshots or MVs it shows Snapshot created.
From ORACLE 8i and later versions,if u create Snapshots or Materialized views it will show Materialized View created

2.
Snapshot is redefined as Materialized view and Query rewrite feature is add

Today I met an artile(http://kbase.redhat.com/faq/FAQ_79_4701.shtm) on redhat Knowledge Base。

Pay attention to the sentence, 'If an application is POSIX compliant or it uses GLIBC (2.2 and above) on a Red Hat Enterprise Linux system, it will usually use the /dev/shm for shared memory (shm_open, shm_unlink).'

When I typed 'df -h' in one of my redhat Linux box. One of the line I got is, 'none 1.3G 0 1.3G 0% /dev/shm'。

我爱北京天安门！

China (Traditional Chinese: 中國; Simplified Chinese: 中国; Hanyu Pinyin: Zhōngguó; Wade-Giles: Chung-kuo; Tongyong Pinyin: Jhōngguó) is a geographical region in East Asia. With over one-fifth of the world's population, the majority of China exists today as a state known as the People's Republic of China, but it also refers to a long-standing civilization compri