Lift the database, the first company you think, usually it will be Oracle. The company was established in 1977 and is initially a company specializing in developing a database. Oracle has been in a leading position in the database. In 1984, the relational database was first turned to the desktop computer. Then, Oracle's next version,
Version 5, the lead in launch new concepts such as distributed databases, client / server structures. Oracle's version 6 started locked mode and symmetrical multi-process computer support ... The latest Oracle8 mainly increases object technology, becoming a relationship - object database system. At present, Oracle products cover dozens of models such as large, medium and small machines, and the 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 are tested by standard SQL and tested by the National Standard Technology (NIST). Compatible with IBM SQL / DS, DB2, INGRES, IDMS / R or the like.
(2) Portability
Oracle's products can run on a wide range of hardware and operating system platforms. It can be installed on more than 70 different large, medium, and small machines; you can work in a variety of operating systems such as VMS, DOS, UNIX, and Windows.
(3) Interpolation
Can be connected to a variety of communication networks, supporting various protocols (TCP / IP, DECNET, LU6.2, etc.).
(4) High productivity
It provides a variety of development tools that can greatly develop further development.
(5) Openness
Oracle has good compatibility, portability, connectivity, and high productivity are oracle RDBMS has good openness.
Oracle products mainly include three types of database servers, development tools, and connection products.
Database server
The latest version is 8, but it is widely used. Version 7 has the following features:
(1) Multi-process, multi-thread architecture
The architecture of multi-process and multi-threads. Oracle7 includes a plurality of clue processes, multiple server processes, and multiple background processes. The clue process is responsible for listening to the user request, and the user requests the user request queue in the memory and returns the execution result in the response queue to the corresponding user. The server process is responsible for handling the user request in the request queue and link the result to the response queue. The number of threads and clues can be dynamically adjusted according to the current workload. Oracle7's process structure makes full use of multi-process machine on the parallel, but due to its process simulation, the operating system scheduling, which weakens the leading advantages of clues.
(2) In order to improve performance improvement core technology
Oracle7 improves its core technology. Its concurrent control mechanism is more exquisite, including unlimited grades, no competitive queries, sequence number generation mechanisms for clues. Added SQL Cache in the shared memory buffer to improve operational efficiency.
(3) High availability
Oracle7 offers a wide range of mechanism support systems such as online backup, online recovery, mirroring, and high availability and fault tolerance.
(4) SQL implementation
Oracle7's SQL complies with the ANSI / ISO SQL 89 standard. Integrity constraints in accordance with the ANSI / ISO standard entity integrity and reference integrity constraints. Provide role-based security.
The role is a collection of permissions. With the concept of role, the security management mechanism wings combine some of the permissions on the table or other database objects to give them a role. You only need to grant the role to a user or a group of users, which can reduce the burden and cost of the security mechanism.
Oracle7 provides parallel server option implementation store sharing for cluster and MPP parallel computer platforms. At the same time, Oracle7 also provides parallel query options for SMP, clusters, and MPP platforms to implement parallel queries, parallel data loading and other operations. Oracle7 provides distributed database features via a distributed option. Its distributed option provides a multi-site distributed query and multi-site update feature, with location transparency and venue autonomous, and provides global database names, support remote procedure calls.
development tools
The development kit provided by Oracle is developer / 2000, Designer / 2000, Discover / 2000, Oracle Office, etc., which covers all aspects of modeling, analysis, design to specific implementation.
Developer / 2000 includes:
Oracle Forms is used to quickly generate screen-based complex applications, with GUI interfaces and multimedia functions, mainly for manipulating data and queries.
Oracle Reports is a tool for rapidly generating reports. It can also generate a variety of complex reports to handle multimedia information.
Oracle Graphics is used to generate a variety of 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 model, analyze, and design complex systems. It can also help users draw ER diagrams, functional hierarchical diagrams, data flow graphs, and square mapping.
Discover / 2000:
This is an OLAP tool that is mainly used to support data warehouse applications. It can explore historical data to find a development trend, analyzing different levels of profile data to find more information about business.
Oracle Office is suitable for office automation, capable of completing information receiving and sending, schedule, calendar management, directory management, and spell checking.
