Database Administrator

New-generation Big Data Distributed Relational Database Initiative Proposal on developing a new generation of big data Distributed Relational Database Li wanhong Today's era has entered the big data era, while nosql databases do not provide powerful

Description of Oracle Index instances and oracle instances Oracle Index instance description-Basics Index is an object used in relational databases to store each record location in a table. It aims to speed up Data Reading and data integrity check.

Mysql advanced permission check principle and mysql permission Principle You can perform database operations in two steps: 1. Whether the connection is permitted. The connection is based on host, name, and password; 2. Are you authorized to

Oracle_set operator, oracle OperatorZookeeper Oracle_set Operator ① UNION/UNION ALLThe UNION operator returns the UNION of two query result sets. Deduplication for the duplicate parts of the two result sets Example:Select id, nameFrom

MySql Index algorithm principle analysis (easy to understand, only talk about B-tree), mysqlb-tree When I first started learning, Baidu went to check it. However, I found that many of them were too complicated to understand. I would like to

Mysql advanced storage process Similar to a function, a piece of code is encapsulated. to execute this piece of code, you can call this stored procedure. in the encapsulated statement body, you can use the if/else, case, while and other control

Atitit. troubleshooting series --- php Program website database error troubleshooting process, atitit --- php Atitit. troubleshooting series --- php Program website database error troubleshooting Process   Errors reported on the Php page cannot

Python Implementation of the Apriori algorithm and python The Apriori algorithm is the originator of Data Mining in the intermediate frequency mode. It became popular since 1960s. Its algorithm concept is also very simple and simple. First, it mines

Local database deployment problems and fixtures, deploymentfixtures /* By Jiangong SUN */ After encountering some problems in deploying databases to local server, here are some tips which cocould be helpful in the database deployment exercises.When

Oracle date calculation, oracle date The Code is as follows: select to_number(add_months(trunc(to_date('2014-11-4 11:13:53','yyyy-mm-dd hh24:mi:ss'),'mm'),1) - trunc(to_date('2014-11-4 11:13:53', 'yyyy-mm-dd hh24:mi:ss'),'mm')) daycountfrom

1-n association ing and hibernate1-n ing in Hibernate1. 1-N Association ing of Hibernate1. Which side is 1 and which side is more?From the business perspective. For example, the relationship between Employee and Department is n-1, and the

Oracle _ constraints constraint and oracleconstraintZookeeper Oracle _ constraints constraint ① What are constraints?1 constraint is mandatory at the table levelThere are five constraints:NOT NULLUNIQUEPRIMARY KEYFOREIGN KEYCHECKNotesIf no

Comparison and analysis of various temporary tables and Efficiency ComparisonComparison and analysis of various temporary tablesOld Shuai (20141107)When writing a stored procedure, temporary tables are often used. What kind of efficiency is better

Mysql addition Error For example, add a user Insert into mysql. user (Host, User, Password) values ("localhost", "test", password ("1234 ")); Error: ERROR 1364 (HY000): Field 'ssl _ cipher 'doesn' t have a default value ERROR For MySQL 5.6

SQL server, SQLAfter a period of study, I also had some knowledge about databases.Databases are basically composed of tables, relationships, and operations. For Beginners, the first thing to learn is:1. How does a database store data?Table,

Jdbc connection hive0.14, jdbchive0.14 Jdbc connection to hive0.14 The latest version on the official website is hive0.13. To download the latest hive, go to git to clone it. Hive0.14 supports direct insertion. Now we will provide an example of jdbc

What is a cursor? DeclareObject_name varchar2 (24 );Type ref_cursor_type is ref cursor;Cursor_object ref_cursor_type;BeginOpen cursor_object'Select regexp_substr (''3h, 4c, 5e, 6b, 7a, 8g'', ''[^,] +'', 1, level)From dualConnect by level

[MongoDB] Build a MongoDB sharding system under the window system (1), windowmongodb This article describes the main principles of sharding clusters. Frankly speaking, I just saw this Sharding system, which is a bit too tall. Seeing us writer Kyle

Rac_udev does not recognize a disk when installing a grid when creating a disk. rac_udevgrid Original Works are from the blog of "Deep Blue blog". You are welcome to reprint them. Please note the following source when reprinting them. Otherwise, you

Rac_grid self-check prompt pdksh-5.2 package missing, rac_gridpdksh-5.2 Original Works are from the blog of "Deep Blue blog". You are welcome to reprint them. Please note the following source when reprinting them. Otherwise, you will be held legally