Database Administrator

Dbms_metadata.get_ddl usage Summary In daily work, some people often use tools to view the definition of objects. In fact, it is annoying to view objects in this way. At work, some colleagues asked me how to get the object definition. Today I will

An instance of RAC cannot be mounted due to the configuration of the DG Broker. Today, I encountered a fault in my own lab. It seemed very simple at first, but it was actually interesting and easy to ignore if I was not careful. We believe that

How to troubleshoot ORA-00845 errors when the database is started Problem description: A node database is down during inspection. When using sqlplus for the system, an empty instance is connected. An error is reported when the database is restarted

Oracle background process function description 1. SMON: System Supervision Process1. It mainly refers to the submitted data, but the data file has not been written to the power-off, and the smon will be restored upon restart.A. Perform rollback to

MySQL 5.6.38 optimized instance 1 Introduction: in daily MySQL SQL statement optimization, you will always encounter various problems. Today, we have encountered a strange problem. Here we will record it for your convenience. MySQL version: MySQL 5.6

MySQL Group Commit Group submission details Group commit is used to optimize disk flushing during log writing. It supports only InnoDB redo log group submission at the beginning, and supports redo log and binlog group submission at the same time in

Rapid deployment of MySQL Databases in Linux1. Download the corresponding software version : Http://mirrors.sohu.com/mysql/MySQL-5.6/ [root@localhost ~]# wget -q http://mirrors.sohu.com/mysql/MySQL-5.6/sql-5.6.36-linux-glibc2.5-x86_64.tar.gz Ii.

Differences between exp/imp and expdp/impdp During normal slave database and database migration, it usually takes several hours to use exp when encountering a large database, which takes a lot of time. It takes much less time for Oracle10g to use

MySQL stress testing tool mysqlslap Mysqlslap is a stress testing tool provided by MySQL. It can simulate a large number of clients operating on the database at the same time, and learn about the database performance through the result

Oracle skip index scan test In Oracle, we know that we can use the Index Skip Scan. However, there are some limitations when we can use the Skip Index Scan.Create table test as select rownum a, ROWNUM-1 B, ROWNUM-2 c, ROWNUM-3 d, ROWNUM-4 e FROM all_

See you on Thursday | from 50 to 0.59 seconds, making SQL optimization impossible by Songhua, IT Jianghu baixiaosheng SpeakerGuest: Zheng Songhua Zhishutang "SQL optimization and Development" course instructor No.: qidan3500 Daniel

Mybatis performs batch update and mybatis performs update. For batch insert of Mybatis, visit http://ljhzzyx.blog.163.com/blog/static/384243122013536375 /. At present, if you want to update data in batches, if the update values are the same, it is

Database SQL Performance Optimization (I): Database SQL Performance Optimization Substr (hbs_bh, 5400) = '000000', optimization processing: hbs_bh like '000000' trunc (sk_rq) = trunc (sysdate), optimization processing: sk_rq> = trunc

Detailed description of Database Server construction and deployment check list, detailed description of Database Preface We may often install and deploy database servers, but we may suddenly forget a certain setting, which poses a risk for future O &

Steps for creating a Postgresql database in Linux: linuxpostgresql Preface PostgreSQL (also called Postgres) is a free object-relational database server (Database Management System), which is released under a flexible BSD-style license. Because the

Comparison between MySQL and Oracle 2 Basic Syntax: mysqloracle Basic syntax No. Category ORACLE MYSQL Note 1 Variables are declared differently. Li_index NUMBER: = 0 DECLARE li_index integer

Summary of the methods for reading and writing files in SQL injection, and summary of SQL Injection reading and writing Preface SQL Injection includes direct SQL injection and file read/write injection. This article describes the content of file

Explain in depth the String concatenation in SQL and explain the SQL String concatenation I. Overview I believe that in daily development, String concatenation is often required in SQL statements. Take sqlserver, oracle, and mysql databases as

Differences between Having and Where in SQL and notes: sqlhaving Differences: The where clause removes rows that do not meet the where condition before grouping query results. That is, data is filtered before grouping. The where condition cannot

Description of SQL Injection Based on Boolean blind injection and description of SQL Boolean Boolean-based blind Injection The Web page only returns True and False. Then, Boolean blind injection is performed after SQL injection, and the relevant