Database Administrator

Video tutorial: http://pan.baidu.com/s/1AaeV8  MongoDB is a distributed file storage-based database. Written in C ++. It is designed to provide scalable, high-performance data storage solutions for WEB applications. MongoDB is a product between

SQLite is a lightweight associated database management system designed for embedded systems. SQLite is a database engine that implements self-dependency, pure client, zero configuration, and supports transactions. It was first developed by D.

According to my knowledge, three of the four domestic databases are developed based on PostgreSQL. In addition, because of the flexible license, anyone can use, modify, and distribute PostgreSQL for free for any purpose, whether it is private,

Designing an application system does not seem difficult, but it is not easy to optimize the system performance. In the development of tools, database design, shouldThere are multiple options for application structure, query design, and interface

PRIMARY KEY) Description from MSDN:A table usually has a column or a group of columns that uniquely identify the values of each row in the table. Such a column or multiple columns are called the primary key of the table, which is used to force the

Actually, ":" Calls the CAST function. Which fields can be converted into one another?You only need to study the cast function to obtain the answer to this question. The cast function information is managed in the pg_cast table of the system.The

Copy codeThe Code is as follows:If OBJECT_ID ('tb') is not null drop table tbIf OBJECT_ID ('temp ') is not null drop table TEMPIf OBJECT_ID ('fun _ nowprice') is not null drop FUNCTION FUN_NOWPRICEIf OBJECT_ID ('fun _ NOWQTY ') is not null drop

1. If there is an Automatically increasing id field, then:Defines two variables: Page, PageCountSelect top PageCount * From [tb_code] Where id> = (select min (id) from (select top (Page-1) * PageCount + 1 id from [tb_code] order by id desc) as t)

Summary:1. Stored Procedure: For SQL statement batch processing, common continuous operations are made into batch processing in the form of application and service.Solve the bottleneck: a large number of SQL queries are slow s2. Index Service:

When designing a relational database, you usually need to specify a primary key for each table. The primary key is the attribute or attribute group that uniquely identifies a row of records in the table. A table can only have one primary key,

I have a business dedicated to storing LOG logs, and there are tens of millions of data every day. So I use the archive storage engine, which is faster in writing and saves space. Here is a brief introduction to the archive storage engine: 650)

The flashback query is introduced in oracle 9i. The flashback query actually uses the UNDO information to obtain the previous data. Since the UNDO space is used cyclically and the pre-transaction image cannot be permanently saved, the flashback

Objective: To test whether oracle hot backup files in windows contain spfile, control files, data files, archived logs, and non-rman recovery are available on different machines and not in the original path. Test environment: windows 2003 R2, ORACLE

The archive mode switching in the RAC environment is slightly different from that in a single instance, mainly because of the differences in shared storage. In this case, we can switch the RAC database to a non-cluster state and switch the archive

When you restore a database, you often encounter errors that cannot be restored successfully. Common Errors are as follows: Message 5070 cannot change the database status when other users officially use the database "" This error occurs

1. Check the oracle instance status: selectinstance_name, version, status, database_statusfromv $ instance; 2. Check the oracle listening process: $ lsnrctlstatus 3. $ ps-ef | grep "ora _" | grep-vgrep Oracle Data File writing process, the output is:

MySQL TRIGGER) usage instructionsThe trigger program is a table-related named database object. This object is activated when a specific event occurs on the table. Mysql 5 and later support triggers. After the trigger is created, the TRG and TRN

Chapter 2: using data processing functionsLike almost any other computer language, SQL supports the use of functionsTo manipulate data. Functions are operations usually saved med on data, usuallyTo facilitate conversion and manipulation.Like most

1. Shell defines the order of user environments 1)/etc/profile The template profile file defined by the Super User applies to every user. 2)/etc/enviroment The template profile file defined by the Super User applies to every user, but only in

Environment: centos 5.6 oracle 11g r2 Primary: 192.168.8.132 str1.example.com str1 master database sid primary Standby: 192.168.8.131 str2.example.com str2 standby database sid standby Oracle 11g software installation