Common Database System comparison Oracle database _oracle

The Oracle tutorial you are looking at is a common database system that compares Oracle databases.
To bring up the database, the first company to think of, is usually oracle. The company was founded in 1977 and was originally a company specializing in the development of databases.
Oracle has a leading position in the database field. In 1984, the relational database was first transferred to the desktop computer. Then, the next version of Oracle,
Version 5, pioneered a new concept of distributed databases, client/server architectures. Oracle version 6 first-line lock mode and for Chenduo processing computers
The support of ... The newest Oracle8 mainly adds the object technology, becomes the relational-object database system. At present, Oracle products are covered with large, medium and small-sized machines, etc.
Dozens of models, Oracle database has become one of the most widely used relational data systems in the world.

Oracle Relational database Products:

Oracle database products have the following excellent features.

(1) Compatibility

Oracle products adopt standard SQL and are tested by the United States National Standards Technology (NIST). Compatible with IBM SQL/DS,DB2,INGRES,IDMS/R.

(2) Portability

Oracle's products can run on a wide range of hardware and operating system platforms. Can be installed in more than 70 different types of large, medium and small machines, can be in VMS,
DOS, UNIX, Windows and many other operating systems work.

(3) Connectivity

Can be connected with a variety of communication networks, support various protocols (TCP/IP, DECnet, LU6.2, etc.).

(4) High productivity

Provides a variety of development tools, can greatly facilitate the user for further development.

(5) Openness

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

Oracle products mainly include database server, development tools and connectivity products three categories.

Database server

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

(1) Multi-process, multiple-lead architecture

Multi-process, multiple-cue architecture. Oracle7 includes one to multiple thread processes, multiple server processes, and multiple background processes. The lead process is responsible for monitoring
The user requests that the user request be chained to the requested queue of memory and the results of the execution in the answer queue are returned to the appropriate user. The server process is responsible for processing the request queue
and link the results to the answer queue. The number of threads and leads can be dynamically adjusted according to the current workload. The ORACLE7 process structure can be fully
The ability of multiprocessor on the parallel machine, but because the clue is simulated by the process, by the operating system, which, to some extent, weakens the advantage of low thread cost.
More sex.

(2) Improving the core technology for improving performance

Oracle7 has improved its core technology. Its concurrency control mechanism is more exquisite, including unrestricted row-level blockade, no competitive query, clue sequence number generation machine
System. The shared SQL Cache is added to the shared memory buffer, which improves the running efficiency.

(3) High availability

Oracle7 provides a variety of mechanisms for online backup, online recovery, mirroring, and so on, with high availability and fault tolerance.

(4) SQL implementation

Oracle7 SQL conforms to the ANSI/ISO SQL 89 standard. Integrity constraints conform to ANSI/ISO standard entity integrity and referential integrity constraints. Provides angle based
The security of the color.

A role is a set of permissions. With the concept of roles, the security management mechanism can be used to combine some of the permissions on a table or other database objects to
Given a role. This role is only required to be granted to a user or group of users, which can reduce the burden and cost of the security mechanism.

For cluster and MPP parallel computer platform, ORACLE7 provides parallel server option to implement disk sharing. At the same time, Oracle7 also for SMP, cluster and MPP flat
The platform provides parallel query options for parallel query and parallel data loading operations.

ORACLE7 provides distributed database functionality through distributed options. Its distributed options provide multiple site distributed queries and multiple site update functions, with a bit
Place transparency and site autonomy, provide global database name, support remote procedure call.

Development tools

The Development toolkit provided by Oracle is developer/2000, designer/2000, discover/2000, Oracle office, etc., which covers the modeling,
Analysis, design to the specific implementation of the various links.

developer/2000 include:

Oracle forms is used for rapid generation of web-based complex applications with GUI interfaces and multimedia capabilities that are used primarily to manipulate data and queries.

Oracle reports is a quick tool for generating reports. Can generate a variety of complex reports, can also handle multimedia information.

Oracle graphics is used to generate a variety of graphical applications.

Oracle books is used to generate online documentation.

designer/2000:

This is the case tool provided by Oracle. This tool can help users to model, analyze and design complex systems. You can also help the user draw the ER diagram, work
Can layer graph, data flow diagram and square chart.

discover/2000:

This is an OLAP tool that is primarily used to support data warehouse applications. It can excavate the historical data to find the development trend, and the general situation of different levels
Data for analysis in order to discover detailed information about the business.

Oracle Office is designed for office automation that enables enterprise-wide messaging and delivery, scheduling, calendar management, directory management, and spelling
Check.

<