Oracle

Introduction

The Oracle Database is an ancient database specially designed for activity grid computing, and is the most flexible and cost effective way to handle the information and applications. In this architecture, each new system can be rapidly provided for the pool of components. There is no need for the maximum workloads, because the capacity can be easily added or re-allocated from the resource pools as needed.

The Oracle database has two structures-

• Logical Structure
• Physical Structure

Logical structure- The structures, contains data segment and extents. Oracle has elegant control of disk space use. Every database is divided into logical storage units called, table spaces or group of table, which relates to the logical structures together.

An each database is logically divided into one or more table spaces. More than two data files are categorically created for each tables pace to physically store the data of all logical structures in a table space. The whole connected size of the data files in a table space is the total storage capacity of the table space.

Physical structure- The physical structures of an Oracle database, contains data files, redo log files, and control files, Etc. There are one or more physical data files in oracle database. Data files consist of all database data. The logical structure data like, indexes, tables, are physically stored in data files in a database. The data of the physical structure and logical structure are separated in the database. The physical storage of data can be managed without affecting the access to logical storage structures.There are many characteristics of data files, like:

1)A data file can be correlated with only one database. Indexes are optional structures associated with tables. Indexes can be created to increase the performance of data retrieval. Just as the index in this manual helps you quickly locate specific information, an Oracle index provides an access path to table data.

• When processing a request, Oracle can use some or all of the available indexes to locate the requested rows efficiently. Indexes are useful when an application index is optional structures associated with tables.
• Indexes are useful when applications frequently query a table for a range of rows (for example, all employees with a salary greater than 1000 dollars) or a specific row.
• Indexes are created on one or more columns of a table. After it is created, an index is automatically maintained and used by Oracle. Changes to table data (such as adding new rows, updating rows, or deleting rows) are automatically incorporated into all relevant indexes with complete transparency to the users.

2) It has provided certain characteristics set to let them automatically extend when the database runs out of space.

3) The logical unit of database storage is a form of one or more data files. This data file is called as table space.

The Modified data or new data is not compulsory written to a data file immediately. It has to reduce the amount of disk storage access and to increase performance, data is pond in memory and written to the appropriate manner of data files all at once and also determined by the database writer process and background process.

Oracle database has created the two type architecture, because of architecture have a more important part of the database. The architecture has created the blueprint of the database and also describe how to perform a database in a particular manner. There are two types of architecture, the first one is Oracle grid architecture and the second one is Application architecture.

1) Oracle Grid Architecture- The oracle grid architecture contains Grid computing and Grid Computing in Oracle Database 10g. In grid computing have consists of three grid structure like infrastructure grid, application grid and information grid.

The Grid computing is an advanced IT architecture, that produces more flexible and affordable prices enterprise information systems. The grid computing provides independent groups, modular hardware and software components, which can be connected and rejoined on demand to meet the changing needs of businesses. The aim of grid computing is some common problem with IT company. The problem of application leads to under dedicated hardware resources, onerous system that are expensive to maintain and difficult to change, and the problem of fragmented and shatter information that cannot be fully overworked by the company as a whole. There are many benefits of grid computing like,

1) The systems designed and implemented in the grid style deliver higher quality of service, lower cost, and greater flexibility at affordable prices.

2) Higher quality of service results from having no single point of failure, a robust security infrastructure, and centralized, policy-driven management.

3) Lower costs obtained by increasing the application of resources. Indexes are optional structures associated with tables. Indexes can be created to increase the performance of data retrieval. Just as the index in this manual helps you quickly locate specific information, an Oracle index provides an access path to table data.

The grid computing is the collection of similar IT assets holistically as a single pond, while exploiting the distinct nature of individual resources within the pool. The grid computing managed in three grids, which includes:

• Infrastructure Grid- The grid resources include hardware assets such as storage, processors, memory, and networks as well as software design to manage the hardware like, databases, storage management, system management, application servers, and operating systems. Infrastructure is the dimension of grid computing, which is the best and most easy structure to understand, but the same concepts are applied to applications grid and information grid.
• Application Grid- An application and information grid is bit of similar grid. Application assets in the grid are the enacting of business logic and process flow with application software. It has a packaged application or custom application, which are written in any of the programming language. In the same manner, the grid computing is better restated and more flexibility of IT infrastructure assets. Grid computing also treats bits of application logic as a resource.
• Information grid-It is a third dimension to grid computing, after the infrastructure and application. Information is a very important dimension to across a company, making it difficult to see the business as a whole or answer basic questions about customers. Without information, about who the customer is and what they want to buy, information assets go under exploited. The information grid, contains message queuing, data propagation, replication, mapping and cleaning tools to ensure the data quality. The  Information grid resources include all data in the company and all metadata required to make that data meaningful. This data may be structured, semi-structured, or unstructured, stored in any location, such as; databases, local file systems, or e-mail servers created by any application.

2) Grid Computing with Oracle Database 10g- In this version of grid computing, experts always want the real solution and their incremental moves towards. They also want the most flexible and productive IT services. In this database family, the software products can implement the basic technologies to get the company started and this grid computing is also providing a robust security, infrastructure, centralized management and powerful development tools. The oracle database 10g includes many other related databases like:

• Oracle Database 10g
• Oracle Application Server 10g
• Oracle Enterprise Manager 10g
• Oracle Collaboration Suite 10g

This grid computing features give the interval of all products and mainly focus on the grid computing capabilities of oracle database.