What is sid in oracle-Oracle-php.cn

Home

Database

Oracle

What is sid in oracle

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

Mar 02, 2022 am 11:22 AM

oracle

In Oracle, sid is the abbreviation of "System IDentifier", which is the unique identifier of the database. It is an initial ID automatically assigned by the system when establishing the database. It appears in the form of an environment variable and is used for Distinguish the forked process from other instances on the system.

What is sid in oracle

The operating environment of this tutorial: Windows 10 system, Oracle 11g version, Dell G3 computer.

What is sid in oracle

SID is the abbreviation of System IDentifier, and ORACLE_SID is the abbreviation of Oracle System Identifier. In the Oracle system, ORACLE_SID appears in the form of an environment variable. In a specific version Under Oracle software installation (that is, ORACLE_HOME), when the Oracle instance starts, the fork process on the operating system must use this SID to distinguish the instance from other instances. This is the role of the SID.

SID means the unique identifier of the Oracle database is an initial ID automatically assigned by the system when you create a database.

SID is used in some DBA operations and interactions with the operating system. To access the instance name from the perspective of the operating system, you must pass ORACLE_SID (environment variable of the operating system), and it also exists in the registry. The database name is needed when installing the database, creating a new database, creating a database control file, modifying the data structure, backing up and restoring the database.

We know that an Oracle instance is composed of a shared memory area (SGA) and a set of background processes; the background process is the channel for interaction between the database and the operating system. These The name of the process is determined by ORACLE_SID.

Only one parameter file is required to start the instance. The name of this parameter file is determined by ORACLE_SID. For the init file, the default file name is init.ora. For the spfile file, the default file name is spfile.ora. Oracle determines and searches for the parameter file to start the instance based on ORACLE_SID. The default location of the parameter file is $ORACLE_HOME/ dbs ($ORACLE_HOME\database directory on Windows).

spfile was introduced from Oracle 9i and became the default parameter file. When Oracle starts the instance, it searches for the parameter file from the default directory in the following order: spfile.ora 'spfile.ora 'init.ora. If these three files do not exist, the Oracle instance will not start.

From this information, we can know that under the same ORACLE_HOME, Oracle can distinguish the instances based on ORACLE_SID; but if they are in different ORACLE_HOME , Oracle will not block ORACLE_SIDs with the same name. In other words, Oracle can create instances of the same ORACLE_SID under different ORACLE_HOMEs on the same host.

Recommended tutorial: "Oracle Video Tutorial"

The above is the detailed content of What is sid in oracle. For more information, please follow other related articles on the PHP Chinese website!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

The Role of Oracle Software: Streamlining Business ProcessesMay 10, 2025 am 12:19 AM

Oracle software simplifies business processes through database management, ERP, CRM and data analysis capabilities. 1) OracleERPCloud automates financial, human resources and other processes; 2) OracleCXCloud manages customer interactions and provides personalized services; 3) OracleAnalyticsCloud supports data analysis and decision-making.

Oracle's Software Suite: Products and Services ExplainedMay 09, 2025 am 12:12 AM

Oracle's software suite includes database management, ERP, CRM, etc., helps enterprises optimize operations, improve efficiency, and reduce costs. 1. OracleDatabase manages data, 2. OracleERPCloud handles finance, human resources and supply chain, 3. Use OracleSCMCloud to optimize supply chain management, 4. Ensure data flow and consistency through APIs and integration tools.

MySQL vs. Oracle: Licensing, Features, and BenefitsMay 08, 2025 am 12:05 AM

The main difference between MySQL and Oracle is licenses, features, and advantages. 1. License: MySQL provides a GPL license for free use, and Oracle adopts a proprietary license, which is expensive. 2. Function: MySQL has simple functions and is suitable for web applications and small and medium-sized enterprises. Oracle has powerful functions and is suitable for large-scale data and complex businesses. 3. Advantages: MySQL is open source free, suitable for startups, and Oracle is reliable in performance, suitable for large enterprises.

MySQL vs. Oracle: Selecting the Right Database SystemMay 07, 2025 am 12:09 AM

MySQL and Oracle have significant differences in performance, cost and usage scenarios. 1) Performance: Oracle performs better in complex queries and high concurrency environments. 2) Cost: MySQL is open source, low cost, suitable for small and medium-sized projects; Oracle is commercialized, high cost, suitable for large enterprises. 3) Usage scenarios: MySQL is suitable for web applications and small and medium-sized enterprises, and Oracle is suitable for complex enterprise-level applications. When choosing, you need to weigh the specific needs.

Oracle Software: Maximizing Efficiency and PerformanceMay 06, 2025 am 12:07 AM

Oracle software can improve performance in a variety of ways. 1) Optimize SQL queries and reduce data transmission; 2) Appropriately manage indexes to balance query speed and maintenance costs; 3) Reasonably configure memory, optimize SGA and PGA; 4) Reduce I/O operations and use appropriate storage devices.

Oracle: Enterprise Software and Cloud ComputingMay 05, 2025 am 12:01 AM

Oracle is so important in the enterprise software and cloud computing sectors because of its comprehensive solutions and strong technical support. 1) Oracle provides a wide range of product lines from database management to ERP, 2) its cloud computing services such as OracleCloudPlatform and Infrastructure help enterprises achieve digital transformation, 3) Oracle database stability and performance and seamless integration of cloud services improve enterprise efficiency.

MySQL vs. Oracle: A Comparative Analysis of Database SystemsMay 04, 2025 am 12:13 AM

MySQL and Oracle have their own advantages and disadvantages, and comprehensive considerations should be taken into account when choosing: 1. MySQL is suitable for lightweight and easy-to-use needs, suitable for web applications and small and medium-sized enterprises; 2. Oracle is suitable for powerful functions and high reliability needs, suitable for large enterprises and complex business systems.

MySQL vs. Oracle: Understanding Licensing and CostMay 03, 2025 am 12:19 AM

MySQL uses GPL and commercial licenses for small and open source projects; Oracle uses commercial licenses for enterprises that require high performance. MySQL's GPL license is free, and commercial licenses require payment; Oracle license fees are calculated based on processors or users, and the cost is relatively high.

See all articles