Database Administrator

Install 1. Create a mongodb folder Create a new mongodb folder, and create a data folder for mongodb as a database 2. Install mongodb Unlike installing SQL, install mongodb by executing the cmd command. Run the cmd command A. Find the bin in the

At the beginning, I never understood why 12306 of the many functions should be separated. For example, the query function of 12306 of the remaining tickets is separated from the ticket purchasing function. In fact, I should consider it with a

A testing environment of the company is based on the oracle 11.2.0.3 database on the linux platform. It is archived and has not been backed up. On the evening of the 21st, % 100 is used for space in the/directory. The oracle HOME Directory is in the

We know that the most popular MySQL standalone version is INNODB, the only engine that supports full transactions. Its characteristic is that the data itself is organized by B-TREE, the data itself is a huge B-TREE index based on the primary key

Create table qResults (tName nvarchar (370), cname nvarchar (3630), [count] int) Declare @ tname nvarchar (200)Declare @ cname nvarchar (200) Declare @ countOut nvarchar (200)Declare @ SQL nvarchar (max)Declare c_search cursorSelect t. name, c. name

I have learned about mysql database performance optimization and design over the past few days. Now I am going to make a summary of my own learning. In the future, I will continue to study in depth and make a summary: 1. Use IndexesEach table can

Archive log is fullORA-00257: How to Handle archiver error. Connect internal only, until freed error1. Log On with the sys userSqlplus sys/pass @ tt as sysdba2. Check the location of the archiv log.SQL> show parameter log_archive_dest;NAME TYPE

1. Select to retrieve a single column SELECT column name From Table NameWhen the output data is not sorted, the order is not certain. 2. Select to retrieve multiple columns SELECT column name, column name 1, column name 2 FROM Table Name 3.

For relational databases, table-based retrieval can achieve good search results by establishing appropriate indexes. (Whether the table design is reasonable or not is not included here)For example, how to retrieve highly selective values such as

Version: 2.2.0InvolvedError: SERVER-5351Operation: Move the data chunk from one Shard to another shard (as described below: Move shard3_2 to shard1_1)Symptom: 1) the move chunk command on mongos is stuck after execution and logs are found: Tue Mar 4

Zookeeper AIX6.1 notes on installing oracle 11204 1. Check the memory size. #/Usr/sbin/lsattr-E-l sys0-a realmem Minimum 1 GB, 2 GB or more   2. Check the size of swap space. #/Usr/sbin/lsps-   3. Check whether the operating system structure can run

The purpose of data mining is to find more high-quality users from data. Next, I went on to discuss the data mining method model in the previous blog. What is a guided data mining method model and how to build a model for data mining. To build a

It is interesting to have a look at the discussion of different roles. Start with Linus: O_DIRECT (Larry McVoy; Linus Torvalds)-Yarchive Note that this post is a little long and has a long time span. It takes a bit of patience to finish reading.

Zookeeper String SQL = "{call INIT_SORT ()}";CallableStatement cs = null;Connection conn = null;ResultSet rs = null;Try {Conn = SessionFactoryUtils. getDataSource (getSessionFactory ()). GetConnection (); Conn. commit ();Conn. setAutoCommit (true );

When you use JDBC to connect to the MySQL database for data insertion, especially continuous insertion of large volumes of data (10 W +), How to improve efficiency? In the JDBC programming interface, Statement has two methods worth

My friend asked: 50 million how to deduplicate a table with data and determine whether the table is repeated based on the two fields. Reply:Select two fields and the primary key id to create a temporary table t1,T1 is used to establish a

// Interface Class package com. syxy. dao; import com. syxy. domain. user; // The dao interface for manipulating the database public interface UserDao {// Add a User public void addUser (user User); // get a User public user getUser (int userId ); //

Copy codeThe Code is as follows: /*** Here is the configuration center of phpPgAdmin. You need to modify the settings here according to your actual situation.** $ Id: config. inc. php-dist, v 1.53 2007/04/18 14:08:48 mr-russ Exp $*/ // A sample

The test machine is always powered off, causing Oracle to not restart automatically after restart. manual operations are required, so you can set it to auto-start mode. Operating System: Linux Database: Oracle 10g 1. vi/etc/oratab Find

When we mention character sets, some people may say that the whole world is clean no matter the sky is split or utf8 is used. However, some character sets require more CPU, more memory and disk space, and even affect index usage. This does not