Introduction of several storage formats of oracle10g database

1 operating system files .

This is the most commonly used approach and is the most commonly used form of non-commercial operating mode (such as the test environment for development or development phase). When you install Oracle, if you choose the format of the operating system files, the Oracle data is stored in the operating system in the form of a file. It's like we play some stand-alone games, and your archive is the same as the operating system files. The advantage of storing data in a file format is that it is easy to move the database. For example, if you copy Oracle's data files directly to a computer, you can quickly replicate the same database system. When reading and writing files, the operating system usually provides a caching form for reading and writing, avoiding excessive reading and writing hard disk damage. Therefore, the use of operating system files to store data, is equivalent to congenital access to the operating system's caching function.

2 bare Partitions .

The bare partition is to write the database directly on the disk, no longer through the operating system of this layer, Oracle dedicated to the partition to read and write. Because there is no operating system this layer, so the speed and performance of reading and writing is a qualitative leap, in some of the Oracle read and write very frequently in the database application, the use of raw partition form to store data can even improve the performance of more than 30%. Of course, if the data store is an operating system file, using RAID under UNIX is also a way to improve performance if the file reads and writes are frequent.

3 Automatic storage Management .

Automated storage management is often referred to as ASM, a new form of storage that is provided after Oracle 10g. This form of storage appears to be a compromise between the first two forms of storage. Neither the file system of the host operating system nor the form of a bare partition is directly read and written by Oracle. It can be seen as an Oracle-specific form of file system. The ASM can store data files, control files, log files, and so on, in ASM, these are also in the form of files, but this time the file format is Oracle's own ASM form. A bit similar to the Linux and ASM is LVM (logical volume management), which can be seen as a new form of file system.

4 Cluster system OCFS (RAC).

What is the full name of RAC, the real application Cluster, is a form of database storage that is shared in a cluster environment. In normal our database, if it is a stand-alone version of the database, when the data file disk is not accessible, then the database is hung up. If it is a cluster shared database, one of the methods is to hold the data files on a node, the rest of the database is shared through NFS or samba, although the data processing power of the database is greatly improved, but if the storage node is dead, the same database will be down. and OCFs is a type of storage without breakpoint recovery, the overall feeling is that each data server has its own file system, but these file systems as if only the same file system, because the data update or other operations are very unified. Even if a computer is hung up, the rest of the server is still running, there is no database exception, and if you want to add a new server is very simple. It is particularly suited for commercial 7x24 service forms.

The 4 types of data storage in

        oracle10g are described, and our most common natural form is the first, but the latter three are more in the business environment. Especially in the large commercial reliability to go to very high applications, the fourth type of RAC form of use is more. Of course, here is a brief introduction to the concept of several file systems. If you want to get a closer look, it's certainly a good idea to consult the Oracle Technical Manual.