今天突然发现连接数据库时报错,用pl/sql dev连接数据时,有时能连接上,有时连接时报:ORA-12520: TNS: 监听程序无法找到需要的
问题描述:
今天突然发现连接数据库时报错,用pl/sql dev连接数据时,有时能连接上,有时连接时报:
ORA-12520: TNS: 监听程序无法找到需要的服务器类型的可用句柄
通过服务器登录数据库,报下面的报连接数错误:
[Oracle@dbserver22 ~]$ sqlplus"/as sysdba"
SQL*Plus: Release 11.2.0.3.0Production on 星期五 11月 14 10:23:23 2014
Copyright (c) 1982, 2011,Oracle. All rights reserved.
ERROR:
ORA-00020: maximum number ofprocesses (150) exceeded
请输入用户名:
ERROR:
ORA-01017: 用户名/口令无效; 登录被拒绝
……
SP2-0157: 在 3 次尝试之后无法连接到ORACLE, 退出 SQL*Plus
[oracle@dbserver22 ~]$
和开发沟通了解后,是因为在昨天晚上有新业务上线,业务量增大,导致连接数上升。
解决办法:
增加进程连接数
--停掉监听
[oracle@dbserver22 ~]$ lsnrctl stop
--杀掉连接进程
[oracle@dbserver22 ~]$ ps -ef |grep LOCAL=NO | cut -c 10-15 | xargs kill -9
--增加连接数
SQL> alter system set processes=650 scope=spfile;
系统已更改。
--重启数据库
SQL> shutdown immediate
数据库已经关闭。
已经卸载数据库。
ORACLE 例程已经关闭。
SQL> startup
ORACLE 例程已经启动。
Total System Global Area1.7103E+10 bytes
Fixed Size 2245480 bytes
Variable Size 6744444056 bytes
Database Buffers 1.0335E+10 bytes
Redo Buffers 21708800 bytes
数据库装载完毕。
数据库已经打开。
SQL> exit
--启动监听
[oracle@dbserver22 ~]$ lsnrctl start
总结:
可能问题的原因很简单,但准确的定位和找出原因是需要经验和技巧的,和开发人员的沟通很重要,最终只要找出原因,解决起来可能就很简单了!
Oracle 单实例 从32位 迁移到 64位 方法
在CentOS 6.4下安装Oracle 11gR2(x64)
Oracle 11gR2 在VMWare虚拟机中安装步骤
Debian 下 安装 Oracle 11g XE R2
本文永久更新链接地址:

MySQL is suitable for beginners to learn database skills. 1. Install MySQL server and client tools. 2. Understand basic SQL queries, such as SELECT. 3. Master data operations: create tables, insert, update, and delete data. 4. Learn advanced skills: subquery and window functions. 5. Debugging and optimization: Check syntax, use indexes, avoid SELECT*, and use LIMIT.

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

MySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.

SQL is used to interact with MySQL database to realize data addition, deletion, modification, inspection and database design. 1) SQL performs data operations through SELECT, INSERT, UPDATE, DELETE statements; 2) Use CREATE, ALTER, DROP statements for database design and management; 3) Complex queries and data analysis are implemented through SQL to improve business decision-making efficiency.

The basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA

The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.

The steps to build a MySQL database include: 1. Create a database and table, 2. Insert data, and 3. Conduct queries. First, use the CREATEDATABASE and CREATETABLE statements to create the database and table, then use the INSERTINTO statement to insert the data, and finally use the SELECT statement to query the data.

MySQL is suitable for beginners because it is easy to use and powerful. 1.MySQL is a relational database, and uses SQL for CRUD operations. 2. It is simple to install and requires the root user password to be configured. 3. Use INSERT, UPDATE, DELETE, and SELECT to perform data operations. 4. ORDERBY, WHERE and JOIN can be used for complex queries. 5. Debugging requires checking the syntax and use EXPLAIN to analyze the query. 6. Optimization suggestions include using indexes, choosing the right data type and good programming habits.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Notepad++7.3.1
Easy-to-use and free code editor