Oracle Database, also known as Oracle RDBMS, or Oracle for short. It is a relational database management system of Oracle Corporation. It is a product that has been at the forefront of the database field. It can be said that the Oracle database system is a popular relational database management system in the world. The system has good portability, convenient use and strong functions, and is suitable for all kinds of large, medium, small and micro-computer environments. It is a high-efficiency, reliable, high-throughput database solution.
ORACLE database system is a set of software products provided by ORACLE Company (Oracle) with distributed database as the core. It is one of the most popular clients/servers (CLIENT/SERVER) or B/S architecture database. For example, SilverStream is a kind of middleware based on database. ORACLE database is the most widely used database management system in the world. As a general database system, it has complete data management functions. As a relational database, it is a complete relationship product; as a distributed database, it realizes distribution. Processing function. But all of its knowledge, as long as you learn ORACLE knowledge on a model, you can use it on various types of machines.
The latest version of Oracle Database is Oracle Database 12c. Oracle Database 12c introduces a new multi-tenant architecture that makes it easy to deploy and manage database clouds. In addition, some innovative features maximize resource utilization and flexibility. For example, Oracle MulTItenant can quickly integrate multiple databases, while AutomaTIc Data OpTImizaTIon and Heat Map can compress data and layer data at a higher density. These unique technological advancements, combined with major enhancements in availability, security and big data support, make Oracle Database 12c an ideal platform for private and public cloud deployments.
MySQL is a relational database management system developed by MySQL AB of Sweden and currently owned by Oracle. MySQL is one of the most popular relational database management systems. In terms of WEB applications, MySQL is the best RDBMS (Relational Database Management System) application.
MySQL is a relational database management system. Relational databases store data in different tables instead of putting all the data in a large repository, which increases speed and increases flexibility.
The SQL language used by MySQL is the most commonly used standardized language for accessing databases. MySQL software adopts dual authorization policy, which is divided into community version and commercial version. Due to its small size, fast speed, low total cost of ownership, especially open source, the development of small and medium-sized websites generally chooses MySQL as the website database.
Thanks to the excellent performance of its community version, PHP and Apache can form a good development environment.
The difference between MySQL and OracleIn general:
Oracle is a large-scale database software, charging, support system is perfect, powerful. A single library can support a large amount of data and high security. Applicable to a more powerful single node or cluster environment.
Mysql is a lightweight database that is small, free, and easy to use. Popular in single-server performance, but supported by a large number of servers.
Typical application scenario
Regarding the "large-scale database", there is no strict definition. It is said that the amount of data is subject to the standard, and it is said that the recovery time shall prevail. In the case of a comprehensive database application scenario, large database applications have the following characteristics: massive data, high throughput; complex logic, high computational complexity, and high availability. From this point of view, Oracle, DB2 is a typical large database, Sybase SQL Server is also considered. The following describes the application scenarios of the previous three databases.
Oracle. Oracle's applications, mainly in the traditional industry's data business, such as: banking, finance, such as the availability, robustness, security, real-time requirements of the business; retail, logistics, such as the massive data storage analysis requirements Business. In addition, high-tech manufacturing such as chip factories are basically inseparable from Oracle; e-commerce also has many users, such as Jingdong (going to Oracle), Alibaba (planning to Oracle). And because of Oracle's strong support for complex computing and statistical analysis, there are more and more applications in Internet data analysis and data mining. A typical scenario is this:
In a data center of a branch of a telecommunications company (non-domestic), there are 4 large servers of Oracle Sun to install the Solaris operating system and Oracle and provide computing services, and 3 Sun Storage disk arrays to provide Oracle data storage, 12 sets. IBM minicomputer, an Oracle Exadata server, a 500T tape drive for storing historical data, San connected to the intranet, using Tuxedo middleware to ensure scalability and lossless migration. Establish an Oracle database that supports high concurrency, use OLTP system to process and manipulate massive data in real time, establish a high-volume Oracle data warehouse, and use OLAP system to analyze revenue data and provide automatic reports. The total budget is about $7.5 million.
MySQL. MySQL is basically born on the Internet and longer than the Internet. Most of its application examples are concentrated in the Internet direction. MySQL's high concurrent access capability is not worse than that of large databases. At the same time, it is cheap, easy to install and use, and is popular among Internet companies. And because of the open source nature of MySQL, for some applications that have special requirements for the database, you can modify the code to achieve targeted optimization, such as SNS, LBS and other Internet services. A typical application scenario is:
At the beginning of an Internet company, there were only a few PCs, and the website framework was quickly set up through the LAMP architecture. With the expansion of the business and the expansion of the market, it has rapidly developed into a medium-sized website for six Dell minicomputers. It took three years to become the largest website in the vertical field. The planned data center has 40 Dell rack servers with a total budget of 200,000 US dollars.
MS SQL Server. Windows ecosystem products, the benefits are very clear. The advantage is that, highly integrated, Microsoft also provides a complete set of software solutions, basically a set of win system installed to survive. Therefore, SMEs who are not so short of money but lack IT talent will prefer MS SQL Server. For example, self-built ERP systems, business intelligence, vertical sector retailers, restaurants, institutions, and more.
In 1996, Bill Gates personally shot the big cow Anders from Borland and got the C# language. Microsoft got ASP.NET in 2002. The mature .NET and Silverlight technologies have won some Internet markets for MS SQL Server. Among them, MySpace, the world's largest social networking site, has a representative history and can be used as a special example [3]. At its peak, there were more than 150 million registered users and 40 billion monthly visitors. It should be regarded as the largest data application supported by MS SQL Server.
Architecture. In fact, the difference between implementation is mainly the difference in architecture. It is the architecture that leads to the difference in interpretation, optimization, and efficiency of the same SQL during execution. I will only make a rough explanation here, so I will not elaborate on it:
Oracle: Data files include: control files, data files, redo log files, parameter files, archive files, password files. This is based on the file function line, and all files are binary-encoded files, which greatly improves the efficiency of the database algorithm. Due to the uniformity of Oracle file management, it is possible to specify and standardize the parsing and optimization of SQL execution:
RBO (rule-based optimizer), CBO (cost-based optimizer)
Through the choice of the optimizer, and the invincible HINT rules, SQL optimization is greatly free, and all aspects of CPU, memory, and IO resources are optimized.
MySQL: One of the biggest features is the freedom to choose a storage engine. Each table is a file and you can choose the right storage engine. Common engines are InnoDB, MyISAM, NDBCluster, etc. But because of this open plug-in storage engine, for example, requires a loose coupling between the database and the engine. As a result, the consistency of the file is greatly reduced. In terms of SQL execution optimization, there are some unavoidable bottlenecks. It is a weakness in multi-table association, sub-query optimization, statistical functions, etc., and only supports extremely simple HINT.
SQL Server: The data architecture is basically divided vertically: Protocol Layer, Relational Engine, Storage Engine, SQLOS. The SQL execution process is a layer-by-layer process. The optimizer in the Relational Engine is cost-based (CBO), and its working process is very similar to Oracle. Above the cost, it also supports a very rich HINT, including: connection prompts, query prompts, and table prompts.
Detailed description (reference: http://zhidao.baidu.com/link?url=LoS9z8jzgXlXIQnv9gy48Vf-OhJDFZao6dj9RtbLTTcMiBwwdp9cz-K8QMQ7_Ff8rr2Gtr3TbYZvKTNuDrl_w_)
More general (reference: http://)
The differences are as follows:First, concurrency
Concurrency is the most important feature of the oltp database, but concurrency involves the acquisition, sharing, and locking of resources.
Mysql: mysql is based on table-level locks. The granularity of resource locking is very large. If a session locks a table for too long, it will make other sessions unable to update the data in this table.
Although the table of the InnoDB engine can use row-level locking, the mechanism of this row-level locking depends on the index of the table. If the table has no index, or the sql statement does not use an index, then the table-level lock is still used.
Oracle: Oracle uses row-level locking, the granularity of resource locking is much smaller, just lock the resources needed by sql, and the locking is on the data row in the database, not dependent on the index. So Oracle's support for concurrency is much better.
Second, consistency
Oracle: Oracle supports the isolation level of serializable, which can achieve the highest level of read consistency. Other sessions can see the changes submitted after each session is submitted. Oracle realizes read consistency by constructing multiple versions of data blocks in the undo tablespace. When each session is queried, if the corresponding data block changes, Oracle will construct the old data of the query for this session in the undo tablespace. Piece.
Mysql: mysql does not have a mechanism similar to oracle for constructing multiple versions of data blocks, only supports the isolation level of read commited. When a session reads data, other sessions cannot change the data, but the data can be inserted at the end of the table.
When the session updates data, it must add an exclusive lock, and other sessions cannot access the data.
Third, the transaction
Oracle has fully supported transactions very early.
Mysql supports transactions in the case of row-level locks in the innodb storage engine.
Fourth, data persistence
Oracle guarantees that the submitted data can be recovered, because Oracle writes the submitted sql operation line to the online online log file, and keeps it on the disk. If the database or host restarts abnormally, Oracle can test online online log recovery client submission after restart. The data.
Mysql: Submit sql statement by default, but if there is a problem with db or host restart during the update process, data may be lost.
V. Submission method
Oracle does not automatically submit by default, requires the user to submit manually.
Mysql is automatically submitted by default.
Six, logical backup
Oracle logical backup does not lock the data, and the backup data is consistent.
MySQL logical backup to lock data, in order to ensure that the backup data is consistent, affecting the normal use of dml business.
Seven, hot backup
Oracle has a mature hot standby tool rman, when hot standby, does not affect the user to use the database. Even if the backed up databases are inconsistent, a consistent reply can be made through the archived logs and the online redo logs at the time of recovery.
Mysql: myisam engine, with mysql comes with mysqlhostcopy hot standby, you need to add a read lock to the table, affecting the dml operation. The innodb engine, which backs up innodb tables and indexes, but does not back up .frm files. When backing up with ibbackup, there will be a log file that records the data changes during the backup, so you can lock the table without affecting other users' use of the database. But this tool is for a fee.
Innobackup is a script used in conjunction with ibbackup, which assists in the backup of .frm files.
Eight, the expansion and flexibility of the sql statement
Mysql has a lot of very useful and convenient extensions to sql statements, such as the limit function, insert can insert multiple rows of data at a time, select some management data can not add from.
Oracle feels more stable in this regard.
Nine, copy
Oracle: There are both traditional data replication for push or pull, and dual-machine or multi-machine disaster recovery mechanism for dataguard. The problem with the main library is that the standby database can be automatically switched to the main library, but the configuration management is more complicated.
Mysql: The replication server configuration is simple, but when the main library fails, the cluster may lose certain data. And you need to manually switch the cluster to the main library.
Ten, performance diagnosis
Oracle has a variety of mature performance diagnostic tuning tools, can achieve a lot of automatic analysis, diagnostic functions. Such as awr, addm, sqltrace, tkproof, etc.
There are fewer diagnostic tuning methods for mysql, mainly slow query logs.
XI, authority and security
The user of mysql is related to the host, it doesn't make sense, and it is more likely to be counterfeited by the host and ip.
Oracle's permissions and security concepts are more traditional, and they are quite satisfactory.
Twelve, partition table and partition index
Oracle's partition table and partition indexing functions are very mature, which can improve the user experience of accessing db.
The partition table of mysql is still not mature and stable.
Thirteen, management tools
Oracle has a variety of mature command lines, graphical interfaces, web management tools, and many third-party management tools, management is extremely convenient and efficient. There are few mysql management tools. The installation of management tools under linux sometimes requires the installation of additional packages (phpmyadmin, etc), which has some complexity.
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