对象权限 select owner, table_name, grantor, privilege, grantable, hierarchy, 'TABLE' /*o.*/ object_type from dba_tab_privs p where p.grantee = 'HR' order by p.owner, p.table_name; 角色 select granted_role, admin_option, default_role from d
对象权限
select owner,
table_name,
grantor,
privilege,
grantable,
hierarchy,
'TABLE' /*o.*/ object_type
from dba_tab_privs p
where p.grantee = 'HR'
order by p.owner, p.table_name;
角色
select granted_role, admin_option, default_role
from dba_role_privs
where grantee = 'HR'
order by granted_role;
系统权限
select privilege, admin_option
from dba_sys_privs
where grantee = 'HR'
order by privilege;
表空间限额
select * from dba_ts_quotas where username = 'SYSMAN' order by tablespace_name;
用户或系统角色对应的权限
select * from role_sys_privs where role = 'RESOURCE'
数据库所有的系统权限名称
select DISTINCT NAME from system_privilege_map t WHERE T.NAME LIKE '%SELECT%'
df -h 磁盘空间使用率
show parameter log_archive_format
查看用户的概要文件
select username, profile from dba_users where username='SCOTT';
查看相应概要文件的各项设置
select resource_name, limit from dba_profiles where profile = 'DEFAULT';
修改相应的概要文件选项
ALTER PROFILE "DEFAULT" LIMIT CONNECT_TIME 30; 最大连接时间30分钟
ALTER PROFILE "DEFAULT" LIMIT FAILED_LOGIN_ATTEMPTS 3; 最大登录尝试次数 3次
rman 启动自动备份控制文件功能
show all;
CONFIGURE CONTROLFILE AUTOBACKUP clear; #清除设置 恢复为默认值
configure controlfile autobackup on; #设置为自动备份控制文件
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 30 DAYS; #修改保留策略为保留30天
backup archivelog all; 备份归档日志
backup tablespace users; 备份users表空间
backup datafile 3; 备份数据文件
backup incremental level 0 database; 零级备份
backup incremental level 1 database; 一级差异增量
backup incremental level 1 cumulative database format '/oradata/bak/dblevel1.bak'; 一级累计增量
backup as compressed backupset datafile 4; 以压缩方式备份数据文件 4
归档空间满时的处理办法
rm *.arc 先用操作系统命令手工删除部分归档文件
rman target /
change archivelog all validate;
delete noprompt expired archivelog all;
RUN { EXECUTE SCRIPT b_whole_10; } 执行rman的脚本
,
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.

MySQL is suitable for beginners because: 1) easy to install and configure, 2) rich learning resources, 3) intuitive SQL syntax, 4) powerful tool support. Nevertheless, beginners need to overcome challenges such as database design, query optimization, security management, and data backup.

Yes,SQLisaprogramminglanguagespecializedfordatamanagement.1)It'sdeclarative,focusingonwhattoachieveratherthanhow.2)SQLisessentialforquerying,inserting,updating,anddeletingdatainrelationaldatabases.3)Whileuser-friendly,itrequiresoptimizationtoavoidper

ACID attributes include atomicity, consistency, isolation and durability, and are the cornerstone of database design. 1. Atomicity ensures that the transaction is either completely successful or completely failed. 2. Consistency ensures that the database remains consistent before and after a transaction. 3. Isolation ensures that transactions do not interfere with each other. 4. Persistence ensures that data is permanently saved after transaction submission.

MySQL is not only a database management system (DBMS) but also closely related to programming languages. 1) As a DBMS, MySQL is used to store, organize and retrieve data, and optimizing indexes can improve query performance. 2) Combining SQL with programming languages, embedded in Python, using ORM tools such as SQLAlchemy can simplify operations. 3) Performance optimization includes indexing, querying, caching, library and table division and transaction management.

MySQL uses SQL commands to manage data. 1. Basic commands include SELECT, INSERT, UPDATE and DELETE. 2. Advanced usage involves JOIN, subquery and aggregate functions. 3. Common errors include syntax, logic and performance issues. 4. Optimization tips include using indexes, avoiding SELECT* and using LIMIT.


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

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

Dreamweaver Mac version
Visual web development tools

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment