Database Administrator

Linux MongoDB configuration + RockMongo management and monitoring 1. Download mongodb-linux-x86_64-2.0.5.tgz 2. Extract 3. mkdir-p/data/monogodbdata 4. start the bin directory: nohup. /mongod -- dbpath =/data/monogodbdata/-- logpath

MySQL improves the buffer for reading abnormal errors (MySQL5.6) What is an error buffer? In MySQL, the Error Buffer only records the last error. If a new error is generated, the old one will be overwritten. If you want to know what errors are

Analysis of MySQ constant transfer MySQL supports constant transfer for expression simplification, as shown in the following example:Create table 't1 '('Id1' int (11) not null default '0 ','A1' int (11) default null,'B1 'int (11) default

MySQL physical query optimization technology-index dive Analysis One guide In the MySQL official manual, there is one sentence: The optimizer can estimate the row count for each range using dives into the index or index statistics. This is to say:

Considerations for MySQL memory usage and Optimization1. read data from memory in microseconds. Read data from a disk in milliseconds. They differ by an order of magnitude. So to optimize the database, the first thing to do is to optimize io.2. The

Set MySQL database to allow remote connection in Linux If the following error occurs when you use a client tool to connect to a MySQL database in Linux: Host '192. 168.1.3 'is not allowed to connect to this MySQL server solution: 1. Access the

ORA-27102: out of memory error handling Problem description: Originally, SGA 4G and PGA 2G. Alter system set sga_max_size = 30G scope = spfile; Alter system set sga_target = 30G scope = spfile; After, SQL> shutdown immediateDatabase closed.Database

Use KeepAlived to build a MySQL high-availability environment Use KeepAlived to build a high-availability MySQL environment.First, set up master-slave replication for MySQL.Enable binlog on the Master node and create a replication account,Then

MySQL builds a replication environment with filtering The Organization is preparing to launch some new functions. These functions have nothing to do with the functions of the original production database module and are ready to create a new database

Oracle tablespace status A few days ago, I asked a question about the table space status and exposed my weak basic knowledge. I summarized the following two blog posts to let myself calm down and fill in the relevant knowledge points, and enhance

Use Oracle analysis functions to randomly extract N records Simulate a song table with a song ID and Author ID, and initialize some data Create table music ( Music_id int primary key, Userid int ); Insert into music (music_id) Select rownum rn

PowerDesigner 15 Overview1. Introduction to PowerDesigner PowerDesigner 15 is a CASE (Computer-Aided Software Engineering) tool integrated with Enterprise Architecture Analysis, UML (Unified Modeling Language), and data modeling launched by Sybase.

SQL transactions and instance demos Introduction Transaction. The English name is transaction. Is a logical unit in the Process of database management operations, composed of a limited operation sequence. In fact, this concept is well understood. A

MongoDB Installation Guide for Ubunu 14.04 0. Environment Description: Ubuntu 14.04, MongoDB2.6.1 1. Import the public Key value from MongoDB to the Ubuntu package system. 2. Create a MongoDB file in the Sources list 3. Reload the local file

MySQL 5.5 Master/Slave Configuration MySQL master-slave replication requires at least two Mysql services. Of course, MySQL services can be distributed on different servers or multiple services can be started on one server. (1) ensure that the MySQL

SQL scaling using Redis I like Redis. This is the only technology that makes you wonder why you need to compile it for so long. Predictable, high performance, and adaptability, which is why I have been using it more and more in the past few years.

QlikView displays the data of the year before the selected time. The customer often asks for this. When the user selects a time, the data of the year before the selected time is displayed in the chart. The following is my method. If there is any

Oracle public redo thread and private redo thread, oracleredo The previous study content is still vague for public redo thread and private redo thread, and the information collected on the Internet is very limited. It seems that some good things

[Sqlite] --> Embedded Database Transaction understanding and instance operations, sqlite Embedded DatabaseSQLite Transaction (Transaction) A Transaction is a unit of work performed on a database. A Transaction is a unit or sequence of work completed

[Sqlite] --> detailed process of connecting to the Sqlite database using jdbc for various data operations, jdbcsqlitePreface:SQLite is a ACID-compliant relational database management system, which is contained in a relatively small C library. It is