Database Administrator

How to handle Oracle lock wait Management of lock wait is a problem that database administrators encounter in their daily work. Generally, large ERP lock wait processes are relatively small, there will be a relatively large number of lock waits for

Hierarchical relationship of dependency through shell analysis table In normal working environments, there will always be dependencies between some tables. For example, we have three tables: customer, subscriber, and account.The customer can have

10 of the best MySQL database Client GUI management tools MySQL has become the most popular open-source database in the past because of its high performance, low cost, and good reliability. Therefore, MySQL is widely used in small and medium

How to change the default value of SQL Server database column attribute is 0, sqlserver2000-- If the field has no default value, run the following statement to add the default value:Alter table name add default (1) for field name-- If the default

Substr usage, substr Sqlplus conn user/user -- connect to database Show user -- display the current user Select upper (substr ('liufeng',) as firstname, lower (substr ('liuyuehui', 4) as secondname from dual; -- display name Substr ('string',

The difference between select count (*) and select count (1) and the difference in efficiency, selectcount  Generally, the returned results are the same for Select Count (*) and Select Count (1 ).    If the table does not have a Primary key, count

Two SQL questions and two SQL statements Department weekly schedule hr_1_planweek: DepartMent name, which is the DepartMent ID. Department table g_group: Gname Department name, gid department id Modify the DepartMent field of the g_group table

Abnormal TXT and logslaveupdates Recently, it was verified that a specific table was copied from the slave database to another master database for adjustment. If log-slave-updates is not configured, the table cannot be synchronized normally. The

Oracle Performance Optimization Operation 15th: function-based index requires equality matching and oracle Performance Optimization In the previous blog examples, we have created a function-based index, but if you execute the following query:

Oracle performance optimization operations: Summary, oracle Performance Optimization These articles about oracle performance optimization can be used in combination with each other. In addition, various methods are closely related to each other.

I have made adjustment configuration items to improve mysql performance, and mysql performance Adjustment Author: fallen flower fragrance Blog: http://blog.csdn.net/qing_gee Preface: I have been studying the configuration items of mysql

SQL Study Notes database topic (2): Development of SQL database under Android, Study Notes for android In Android development, databases are indispensable. In Android development, sqllite is a small embedded database. Today I will write two articles

Updates information in the database.Author:Www.gudianxiaoshuo.comThis article is organized by the Code Assistant Software and released content is irrelevant to this software.More comfortable reading, more comfortable writing, and easier

Note the first wave of high-performance mysql, high-performance mysql Author: fallen flower fragrance Blog: http://blog.csdn.net/qing_gee Preface: This article provides some experiences after reading "High Performance mysql. The project has been in

SQL statement summary [update], SQL statements are constantly updated 1: query the number of tables in the database dbName. Select count (*) from information_schema.tables where table_schema = 'dbname '; 2: Merge tables based on a field Select id,

PostgreSQL common SQL, pgsql 1. view the current database connection SELECT pg_stat_get_backend_pid(s.backendid) AS procpid, pg_stat_get_backend_activity(s.backendid) AS current_query FROM (SELECT pg_stat_get_backend_idset() AS backendid)

Demonstration of DB Query Analyzer 6.03 Installation and Running on Microsoft Windows 8, Demonstration of DB Query Analyzer 6.03 Installation and Running on Microsoft Windows 8 Ma Genfeng (Guangdong Unitoll Services ininitialized ated, Guangzhou 5103

08. Application of stack (II) and 08 Application1. Stack application-recursion 1. Recursive Function: Call a function directly or indirectly by calling itself or through a series of call statements, called a recursive function. 2. Stack and

Postgresql data exists in one table, and the other table does not meet the integrity search requirements.There are two tables T1 and T2. The table structure and data are as follows: create table t1 ( id int);create table t2 ( id int, finished int)

Rman recovery from different machines and rman recoveryRman recovery from different machines Note: 1. the directory structure of the source database and target database is the same 2. The target database only needs to install the ORACLE software