Database Administrator

MySQL index and Query Optimization Index type: Common indexes are the most basic index types and have no restrictions such as uniqueness. The unique index is basically the same as the normal index, but all index column values are unique. The primary

MySQL explain analysis Query Brief description: You can use the EXPLAIN or DESC keyword to simulate the optimizer to execute SQL query statements to know how MySQL processes your SQL statements. This helps you analyze the performance bottleneck of

Mydumper-MySQL Database Backup Tool Mydumper is a MySQL database server backup tool, which is much faster than mysqldump. It also provides the ability to obtain remote server binary log files while dumping. Advantages of Mydumper Parallel

Monitor multiple database loads simultaneously using Shell scripts In normal work, there are still a lot of databases to be managed. Because of the relationship between remote access and permissions, some graphic tools cannot be accessed. Sometimes

The COMPRESSION parameter COMPRESSION ratio of Oracle 11g EXPDP is comparable to that of "gzip-9" This compression ratio can be comparable to the operating system "gzip-9". In some cases, it may be more efficient than gzip. For your reference. 1.

Explore Redis data expiration policies Use the EXPIRE key seconds command to set the data expiration time. If the return value is 1, the setting is successful. If the return value is 0, the key does not exist or the expiration time cannot be set

Use Shell scripts to view database tablespace usage Check the table space in the database. You may have a lot of scripts in use. You can also read it and share an example of using shell scripts to check the table space usage.The script is as follows:

MySQL remote connection failure Solution I have encountered the problem that MySQL can be connected locally but cannot be connected remotely. I have not recorded the problem. I encountered this problem on the new ECS instance on the cloud today. I

Python accesses the MySQL database and supports addition, deletion, modification, and query. Overview:I want to know more about accessing the MySQL database. However, since I recently learned Python, I will use Python to implement it below. These

Updated materialized views of PostgreSQL 9.4 PostgreSQL version 9.4 has been released for a while and has updated a lot of content. One of them is the update of materialized views that are of interest. Compared with the original materialized view

MySQL Character Set GBK to UTF8 In the production environment, the character set of the MySQL database needs to be upgraded for various reasons. For example, to support Chinese characters, the character set of latin1 must be upgraded to GBK, you

MySQL 'root' @ 'localhost' cannot be logged on This morning, my colleague said that the MySQL root Account could not be logged on. I tried it.# Mysql-u root-pPrompt "Access denied for user 'root' @ 'localhost' (using password: YES )" Because a

Data structure, data structure and AlgorithmHash search In the previous search algorithm, the time complexity is O (n) or O (2n). The efficiency depends on the number of "comparisons. Even if the search results of a table using the sort tree

Special cases of innodb RC lock, innodbrc In MySQL5.7, when read committed isolation level is used, or the deprecated innodb_locks_unsafe_for_binlogsystem variable is enabled, there is no InnoDBGap locking checks tfor foreign-key constraint checking

Rising Temperature, risingtemperature Given a Weather table, write a SQL query to find all dates Ids with higher temperature compared to its previous (yesterday's) dates. + --------- + ------------ + ---------------- + | Id (INT) | Date (DATE) |

[Translated from mos] bug-Wrong Kernel Statistic and mosbug-wrong between Oracle Linux 5.9 and Oracle Linux 6.4Bug between Oracle Linux 5.9 and Oracle Linux 6.4 -- Wrong Kernel Statistic in Version 2.6.39-400. X. XReference:Wrong Kernel Statistic in

Reading schema error: null, readingschema Solution: add dbo The complete hibernate. cfg. xml is as follows: com.microsoft.sqlserver.jdbc.SQLServerDriver jdbc:sqlserver://localhost:1433;DatabaseName=Lessonra

Materialized View, index view, and function index. DESC is used when an index is created, and desc is materialized. I searched the information for a task assigned by the boss and thought it would be better to summarize it. What if I use it later?

Install MySQL in Ubuntu and unzip tumysql Enter sudo apt-get install mysql-server mysql-client on the terminal During the installation process, you will be asked to enter the password of the root user (the user managing the MySQL database, not the

The retrieval method after the Oracle11g user password is forgotten. The oracle11g User Password The Oracle11g installed on your computer has a userRootIt was useless for a long time, and the password was forgotten. The following describes how to