Comparison of common database systems with Oracle databases

The ORACLE tutorial is: Compare Oracle databases with common database systems. When talking about databases, the first company that comes to mind is generally Oracle. Founded in 1977, the company was initially a specialized database development company.
Oracle has been in the leading position in the database field. In 1984, relational databases were first transferred to desktop computers. Then, the next version of Oracle,
Version 5 takes the lead in introducing new concepts such as distributed databases and customer/Server structures. Oracle version 6 is the first line lock mode and a Symmetric Multi-processing computer
...... The latest Oracle8 mainly adds object technology to become a relational-object database system. Currently, ORACLE products cover large, medium, and minicomputers.
With dozens of models, Oracle databases have become one of the world's most widely used relational data systems.

Oracle relational database products:

Oracle Database has the following excellent features.

(1) Compatibility

Oracle adopts standard SQL and has been tested by NIST. Compatible with ibm SQL/DS, DB2, INGRES, IDMS/R, etc.

(2) portability

Oracle products can run on a wide range of hardware and operating system platforms. It can be installed on 70 or more large, medium, and small computers. It can be installed in VMS,
Work in multiple operating systems, such as DOS, UNIX, and WINDOWS.

(3) connectability

Can be connected to multiple communication networks and support various protocols (TCP/IP, DECnet, LU6.2, etc ).

(4) High Productivity

A variety of development tools are provided to facilitate further development.

(5) Openness

Oracle's good compatibility, portability, connectivity, and high productivity are good open features of Oracle RDBMS.

ORACLE products mainly include database servers, development tools, and connection products.

Database Server

The latest version is 8, but 7 is widely used. Version 7 has the following features:

(1) multi-process and multi-clue Architecture

Multi-process and multi-clue architecture. Oracle7 includes one or more clue processes, multiple server processes, and multiple background processes. Lead process monitors
User requests, link user requests to the Memory Request queue, and return the execution results in the response queue to the corresponding user. The server process is responsible for processing request queues.
And link the result to the response queue. The number of threads and threads can be dynamically adjusted based on the current workload. The process structure of Oracle7 is sufficient.
The multi-processor capability on the parallel machine is used. However, because the clues are simulated by processes and scheduled by the operating system, the advantage of low clue overhead is reduced to some extent.
.

(2) core technologies for improving performance

Oracle7 has improved its core technologies. Its concurrency control mechanism is more refined, including unlimited row-level blocking, no competition queries, and clue sequential number generation machines.
. The shared SQL Cache is added to the shared memory buffer to improve the running efficiency.

(3) High Availability

Oracle7 provides multiple mechanisms to ensure high availability and fault tolerance.

(4) SQL implementation

Oracle7 SQL complies with ANSI/iso SQL 89 standards. Integrity constraints comply with the ANSI/ISO standards for entity integrity and referential integrity constraints. Provides angle-based
Color security.

A role is a set of permissions. With the concept of roles, the security management mechanism can combine some permissions on tables or other database objects and combine them
Assign a role. When needed, you only need to assign this role to one user or a group of users, which can reduce the burden and cost of the security mechanism.

For clusters and MPP parallel computer platforms, Oracle7 provides parallel server options for disk sharing. At the same time, Oracle7 is also SMP, cluster, and MPP
The platform provides parallel query options to achieve parallel query, parallel data loading, and other operations.

Oracle7 provides distributed database functions through distributed options. Its distributed options provide multi-site distributed query and multi-site update functions with bit
Provides global database names and supports remote process calls.

Development Tools

The Development kits provided by Oracle are Developer/2000, Designer/2000, Discover/2000, and Oracle Office,
Analysis, design, and implementation.

Developer/2000 includes:

Oracle Forms is used to quickly generate complex screen-based applications. It has GUI and multimedia functions and is mainly used to manipulate data and query.

Oracle Reports is a quick report generation tool. It can generate various complex reports and process multimedia information.

Oracle Graphics is used to generate various Graphics applications.

Oracle Books is used to generate online documents.

Designer/2000:

This is the CASE tool provided by Oracle. This tool can help users build, analyze, and design complex systems. It also helps users draw ergraphs and functions
Hierarchical, data flow, and positional graphs.

Discover/2000:

This is an OLAP tool mainly used to support data warehouse applications. It can mine historical data to find development trends and give an overview of different levels.
Data is analyzed to find detailed information about the business.

Oracle Office is applicable to Office automation. It can receive and send enterprise-wide messages, schedule, calendar management, directory management, and spelling.
Check.

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