Comments on the technical features of the mainstream open source database

As open source software is used more and more widely, like Linux operating system, open source database has its inevitability. When Oracle, IBM, Microsoft, Sybase and several major database vendors in the field of database monopoly, the emergence of MySQL, PostgreSQL as the representative of the Open source database system, to promote the development of Open-source software business. Open source database system is not a new thing, such as Postgres (predecessor of PostgreSQL) has 20 years of development history, and the famous MySQL this April just spent its 10 anniversary event.

1, MYSQL

MySQL is the Swedish t.c.x company responsible for development and maintenance, it is a real multi-user, multi-threaded SQL database server. MySQL implements its functionality in a client/server architecture that consists of a server daemon mysqld and many different client programs and libraries. SQL is a standardized language that makes it easier to store, update, and access information. MySQL's main features are fast, robust, and easy to use. The official pronunciation of MySQL is "my Ess Que Ell" (not My-sequel). The latest version of MySQL is 5.0,mysql's Web site: Http://www.mysql.com,MySQL's logo is a small dolphin. See Figure 1.

　

Figure-1 Mysql logo

The technical features of MySQL:

1. It uses a core thread that is full multithreading and supports multiple processors.

2. There are several types of columns: 1, 2, 3, 4, and 8 byte-length private symbols/unsigned integers, FLOAT, DOUBLE, CHAR, VARCHAR, TEXT, BLOB, DATE, Time, DATETIME, TIMESTAMP, year, and enum types.

3. It implements SQL function libraries with a highly optimized class library and is as fast as they can, usually without any memory allocations after the query is initialized. No memory vulnerabilities.

4. fully supports the SQL's group BY and ORDER BY clauses, which support aggregate functions (count (), Count (DISTINCT), AVG (), STD (), SUM (), MAX (), and Min ()). You can mix tables from different databases in the same query.

5. Left 0UTER join and ODBC support for ANSI SQL.

6. All columns have default values. You can insert a subset of a table column with inserts, and those that do not have the specified value are set to their value.

7. MySQL can work on different platforms. Supports C, C + +, Java, Perl, PHP, Python, and Tcl APIs.

MaxDB is the new name for SAP DB after the 2003 SAP Company and MySQL AB Co. MaxDB is a heavyweight, obtain SAP R/3 certification, suitable for online transaction processing and online analytical processing, such as a variety of business types of high availability, high reliability and highly scalable database, support High-volume users and concurrent business operations, the use of multithreaded multi-process server design, support multiprocessor applications, It provides high reliability through clustering and thermal deployments, supports terabytes of massive data, and supports complex applications such as enterprise-class data synchronization and replication.

2. PostgreSQL

PostgreSQL is a free open source relational database running on UNIX and Linux operating systems (which can also run on NT platforms with Cygnus). Originally developed by the University of California, Berkeley, it began as a presentation system, but over time, it was gradually distributed, and many practical applications were made to become popular. Postgresq's web site is http://www.postgresql.org/, the latest version is the October 4, 2005 release of 8.0.4. PostgreSQL's official pronunciation is: post-gres-q-l. Postgresq's logo is an elephant, see figure-2.

Figure 2 PostgreSQL logo