PostgreSQL
PostgreSQL is a free software feature is complete the object - relational database management system (ORDBMS), can be said is the world's most advanced, most powerful free database management system. PostgreSQL is the Department of Computer Science University of California, Berkeley, the development of POSTGRES, Version 4.2, based on object-relational database management system (ORDBMS). POSTGRES leading many of the concepts only in very late when it appears in the commercial database.
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PostgreSQL PostgreSQL Introduction brief history of the Berkeley POSTGRES project Postgres95 describes the main features of PostgreSQL PostgreSQL introduced
PostgreSQL About PostgreSQL is an original Berkeley code open source successor. Berkeley (BSD) the contribution of computer science can be described as a huge development in the entire history of computer science, almost everywhere in this school of researchers and students of the footprint. PostgreSQL supports most of the SQL standard and offers many other modern features: complex queries, foreign keys, triggers, views, transactional integrity, multi-version concurrency control. Similarly,
air force one low nike, PostgreSQL can be extended in many ways, for example, by adding new data types, functions, operators, aggregate functions, index methods, process language. And, because the permit flexible, anyone can use for any purpose free of charge, modify, and distribute PostgreSQL, whether private, commercial or academic use. Brief history of PostgreSQL PostgreSQL is now known as the object - relational database management system (a time known as the Postgres95) from the POSTGRES package written at Berkeley evolved. After ten years of development, PostgreSQL is the world get the most advanced open source database system, which provides a multi-version concurrency control, supporting almost all SQL components (including sub-queries, transactions, and user-defined types and functions), and can be very wide scope (development) language bindings (including C, C + +, Java, perl, tcl, and python). Michael Stonebraker Berkeley POSTGRES project, led by Defense POSTGRES project Advanced Research Projects Agency (DARPA), Army Research Office (ARO), National Science Foundation (NSF), and ESL, Inc co-sponsored. Implementation of POSTGRES began in 1986, described the initial concept of the system design of POSTGRES. The first data model defined in The POSTGRES Data Model. The rules at that time in the POSTGRES rules system design described in the design of the system. Storage Manager theoretical basis and architecture design of the POSTGRES storage system is described in detail. Since then, POSTGRES has undergone several major version update. The first Published in the June 1989 version 1 to the number of external users. In response to the user on the first rule of the critics, re-design the rules of the system, and in June 1990 announced the new rule system version 2. Version 3 appeared in 1991, an increase of support for multiple storage managers, and improved query executor, re-write the rules system. Since then, the next pre-release version until Postgres95 work has focused on the portability and reliability. POSTGRES has been a lot of research or practical application has been applied. These applications include: a financial data analysis system, a jet engine performance monitoring package, an asteroid tracking database, a medical information database and a number of geographical information systems. POSTGRES also many universities for teaching purposes. Finally, Illustra Information Technologies Illustra Information Technologies (later merged into Informix) which now belongs to IBM) to get the code and make it commercial. In late 1992, Sequoia 2000 scientific computing POSTGRES became the primary data manager program. By 1993, almost doubling the number of external users. As users increase. Time for source code maintenance growing up too much of this time should be used for the database, in order to reduce the burden of support, the Berkeley POSTGRES project officially terminated when the version 4.2. Postgres95 introduced in 1994, Andrew Yu and Jolly Chen added to the POSTGRES SQL language interpreter. And then Postgres95 posted to the internet for the source code we use, as an open source, the original POSTGRES Berkeley code successor. Postgres95 All source code is completely ANSI C, and the code is reduced by 25%. And there are many internal changes in order to facilitate improved performance and code maintainability. Postgres95 version 1.0.x during the Wisconsin Benchmark test about 30-50% faster than the POSTGRES v4.2. In addition to several bug fixes, the following are some major improvements: the original SQL query language PostQUEL be replaced (in the server side implementation). PostgreSQL does not support the sub-query before) (but this feature can Postgres95 inside SQL user-defined function implementation). Re-implement the aggregation. Also adds support for GROUP BY query clause. Program can still call the libpq C interface functions. Increase in the use of GNU Readline new interactive SQL query (psql). This program largely replaced the old monitor program. Added a new front-end library, libpgtcl, to support the Tcl-based clients. A sample shell, pgtclsh, provided new Tcl command for Tcl procedures and Postgres95 back-end interaction. Completely rewrite the large object interface. Retains large objects will be reversed (Inversion) as the only mechanism for storing large objects. (Removed the inverted (Inversion) file system.) Removed the record level (instance-level) system of rules. But we can still use the rules by rewriting the rules. Increase in the release of source code in a short common SQL and SQL-specific features Postgres95 tutorial. Use GNU make (instead BSD make) used to make. Postgres95 patch can be used without the GCC (revised even bytes of data (doubles) the alignment problem). PostgreSQL introduced to 1996, we are very obvious to see the So we played a new name to reflect the original POSTGRES PostgreSQL and the latest version of the use of the relationship between SQL. At the same time to re-build numbers starting from 6.0, the version number will be put back to the beginning of the beginning of the project by the Berkeley POSTGRES order. Postgres95 focus on the marked version of the development and understanding of the existing back-end code issues. PostgreSQL development focus to a number of controversial features and functionality of the above, of course,
nike air force one low, while all aspects of the work are under way. The main features of PostgreSQL PostgreSQL can be said that the most characteristic free database management system, we can also say that even the most powerful free software database management system. In fact, PostgreSQL features covers SQL-2/SQL-92 and SQL-3/SQL-99, first of all, it includes can be said is the world's most extensive support for data types, data types, some of which can be connected commercial databases do not have, such as IP type and geometry types; Secondly, PostgreSQL is a full-featured free software database, a long time, PostgreSQL is the only support services,
air force 1 shoes, sub-queries, multi-version concurrency control system, data integrity checks The only features such as a free software database management system. Until recently, and SAP, Inprise's InterBase its original proprietary software vendors will open after the break for the free software this one. Finally, PostgreSQL has a very active development team, the current staff have submitted more than thirty people, and the efforts of many hackers, PostgreSQL increasing the quality, but also from the other side increased the confidence of people to use PostgreSQL, After all, the database management system as a desktop operating system is not like a dang day also make people feel quite satisfied:-P. From a technical point of view, PostgreSQL uses a more classic C / S (client / server) structure, which is a client corresponds to a server-side daemon mode, the daemon of the client to query the request, generate plans tree, data retrieval and formatting the final output of the results returned to the client. In order to facilitate the preparation of the client's program, provides a unified by the database server the client C interface. The client interface is different from the C interface, such as ODBC, JDBC, Python, Perl, Tcl, C / C + +, ESQL etc.,
nike air force one, but also pointed out that, PostgreSQL support for the interface is also very rich, almost supports all types of database client interface. This also can be said to PostgreSQL a big plus. Having advantages, can not but say a few shortcomings, not because it is biased towards free software and PostgreSQL, starting from the Postgres, PostgreSQL has suffered a number of changes. First of all, the early PostgreSQL inherited almost all of Ingres, Postgres, Postgres95 question: Institute of taste too, because its purpose is the database the first study, therefore, whether in stability, performance and ease of use, the emphasis has not been a long time, until PostgreSQL project began, the situation was getting better and better, at present, PostgreSQL is fully capable of any size in the range of applications within the business. There are reports the size of the production database has been TB-level data, has been close to 32-bit computing to the limit. Institute of taste but also brought an unexpected bonus PostgreSQL: probably because the universities are too different hardware and software environment's sake, it is the largest currently supported platform for a database management system, a platform supported by many as a dozen species, including different systems, different hardware systems. So far, it still maintained a support platform database management system up to the title. Secondly, PostgreSQL does still lack some of the more high-end database management system requires the features, such as database clustering, better management tools and a more automated system optimization and other mechanisms to improve database performance. However, having said that, PostgreSQL has a very strong expansion of capacity, you can be easily extended data types, internal functions, aggregation operators, etc.,
air force 1 high, and, do not forget, you have all the source code, in theory, you can do anything you can do. Therefore, many shortcomings will disappear in the twinkling of an eye is normal. All in all, PostgreSQL's character has fully meet the needs of most users, but also the quality and characteristics of its land still in progress with each passing day, so we have reason to believe that in the near future, PostgreSQL can certainly be a good, free ,
air force one high, the alternative to commercial databases. Atlas Atlas entry for more extended reading: 1
PostgreSQL 8.0.0 Chinese documents (PostgreSQL Chinese production)
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http://www.postgresql.org/
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http://www.pgsqldb.org/
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http://tech.ccidnet.com/art/1105/200...1300105_1.html
Open Category: databases, computer PostgreSQL
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