删除日志文件的语法如下:alter database drop logfile member logfile_name;删除日志文件需要注意如下几点:1.该日志文件所在的
删除日志文件的语法如下:
alter database drop logfile member logfile_name;
删除日志文件需要注意如下几点:
1.该日志文件所在的的日志文件组不能处于current状态,需要执行一次手动日志切换,将该日志文件组的状态修改为inactive
2.该日志文件所在的日志文件组中必须包含有其他的日志成员。
3如果数据库运行在归档模式下,则应该在删除日志文件之前,确定它所在的日志文件组已经被归档,,否则会导致数据丢失。
日志文件组的状态值:
active current inactive unused
Oracle日志文件的状态值:
valid invalid stale
删除日志文件组
语法如下:
later database drop logfile group group_number;
删除日志文件组需要注意如下的几点
1.一个数据库至少需要两个日志文件组。
2.日志文件组不能处于current状态。‘
3.如果数据库运行在归档模式下,应该确定该日志文件已经被归档。
SQL> alter database drop logfile member
2 'f:\oracledata\redo4.log';
以上的sql语句只是将该数据日志文件在控制文件和数据字典中删除,操作系统下并没有被删除
数据库已更改。
如下查询系统中的数据库日志文件组
SQL> select group#,member from v$logfile;
GROUP# MEMBER
-------------------------------------------------------------------------------
3 D:\ORACLE\ORADATA\ORACLE12C\REDO03.LOG
2 D:\ORACLE\ORADATA\ORACLE12C\REDO02.LOG
1 D:\ORACLE\ORADATA\ORACLE12C\REDO01.LOG
4 F:\ORACLEDATA\LOGFILE\REDO1.LOG
4 F:\ORACLEDATA\LOGFILE\REDO2.LOG
以上内容来自学习的记录。
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

Atom editor mac version download
The most popular open source editor

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.

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

Dreamweaver CS6
Visual web development tools