Oracle11.2新特性之儲存

11.2版本除了進一步推進基於ASM的儲存（ASM整合進Grid Infrastructure），ASM Cluster File System (ACFS)外，針對儲存層的最新進展，增加了如下特性。

下面部分均摘自《Oracle Database New Features Guide 11g Release 2 (11.2)》

1, 支援備份到雲端儲存
1.2.1.2 Backup to Amazon Simple Storage Service (S3) Using OSB Cloud Computing
Oracle now offers backup to Amazon S3, an internet-based storage service, with the Oracle Secure Backup (OSB) Cloud Module. This is part of the Oracle Cloud Computing offering.

This feature provides easy-to-manage, low cost database backup to Web services storage, reducing or eliminating the cost and time to manage an in-house backup infrastructure.

You can use the Oracle Secure Backup Cloud Module to backup databases starting with Oracle Database 9i Release 2 or higher.

2 支援solid state device (SSD)作為SGA的二級快取
1.8.1.1 Database Smart Flash Cache

New in Oracle Database 11g Release 2 (11.2), the Database Smart Flash Cache feature is a transparent extension of the database buffer cache using solid state device (SSD) technology. The SSD acts as a Level 2 cache to the (Level 1) SGA.

Database Smart Flash Cache can greatly improve the performance of Oracle databases by reducing the amount of disk I/O at a much lower cost than adding an equivalent amount of RAM.

3，支援4KB Sector Disk Drives
1.8.1.4 Support 4 KB Sector Disk Drives
Today, disk drives have 512 byte sectors. Disk drive manufacturers are moving to 4 KB sector drives because it allows them to offer higher capacity with lower overhead. If customers use 4 KB sector drives as 512 byte sector drives, then there is likely to be a performance penalty (because they have to run in 512 byte emulation mode). This feature allows Oracle to work with 4 KB (and 512 byte) sector drives without a performance penalty. There is also the capability in Automatic Storage Management (ASM) to allow migration of a disk group from 512 byte sector drives to 4 KB sector drives.

This feature allows customers to take full advantage of new generation, higher capacity disk drives.

4，支援4KB Sector Disk Drives
1.11.3.1 Database File System (DBFS)
The Oracle Database File System (DBFS) enables the database to be used as a POSIX-compatible file system on Linux. This feature includes a PL/SQL package on the database server that enables the DBFS server functionality and a Linux client for DBFS (dbfs_client). The dbfs_client client is a utility that enables mounting of a DBFS file system as a mount point on Linux. It provides the mapping from file system operations to database operations. The dbfs_client client runs completely in user space and interacts with the kernel through the FUSE library infrastructure.

DBFS Hierarchical Store provides an easy and application-transparent way to archive SecureFiles data that is stored in DBFS file systems to secondary storage tiers such as tape and storage clouds, using DBFS Links. It also allows archived data to be dearchived and brought back into the database on demand.

DBFS makes it easy for files to be accessed by database applications, and for file-based tools to access files stored in the database. With DBFS, all important file data can be seamlessly stored in an Oracle database, providing the benefits of security, backup, performance, and scalability that are standard with the Oracle Database.

SecureFiles is a high performance solution for storing files or unstructured data in Oracle Database. Customers often need to store these files for long periods of time for business or compliance reasons. Consequently, customers are looking to transfer files to cheaper forms of storage in an application-transparent manner to reduce manageability and administration overhead. DBFS Hierarchical Store provides a seamless, automatic, and transparent way to archive cold file data to inexpensive storage.