Database Administrator

Data structure, data structure and AlgorithmArray definition sequence expression and implementation of Arrays Because the memory structure of the computer is one-dimensional, one-dimensional memory is used to represent multi-dimensional arrays, and

Mysql Study Notes 6 (Data Definition Language DDL), learning notes ddlThe SQL language includes four main programming languages: Data Definition Language (DDL), data operation language (DML), and data control language (DCL) there is also a

Database set Query Database collection operations mainly include three aspects: 1. Union merge rows Union is used to merge two query results and deduplicate the same row while merging. For example: If we need to display all the union sets

Report data source-Hadoop, report hadoop In addition to traditional relational databases, the data source types supported by computing reports include TXT text, Excel, JSON, HTTP, Hadoop, and mongodb. For Hadoop, you can directly access Hive or read

A ing method between RDBMS database tables and Redis models, rdbmsredis Some time ago, in the selection of memory databases, there was still a gap between Aerospike and Redis. Because Redis has already had many successful cases in the industry, and

Detailed description of telnet connection to memcache server, telnetmemcache As an excellent out-of-process cache, memcache is often used in high-concurrency system architecture. Here we will talk about how to use the telnet tool to view the running

Mysql Study Notes 1, mysql Study NotesDatabase Operations 1. Create a database Create database databasename Return Query OK Error 1007 is returned if an Error occurs. 2. view all databases Show databases Note: It

MongoDB BASICS (3) Use of indexes in mongodb and mongodb Indexes The indexes in MongoDB are similar to those in other databases and use the B-Tree structure. MongoDB indexes are at the collection level and support creating indexes in any column or

Difference between SQL server and oracle: sqloracle Reproduced in: http://blog.csdn.net/it_fengli/article/details/8213839 -- Difference between SQL server and oracle:-- DBMS Database Management System -- 1. Different data types. -- SQL server data

MySQL obtains all the date points of a month, mysql date1. Problems As the title says, use MySQL to get all the days of a month in a certain year. For example, obtain all dates of January 1, February 2014. 2. handling process 2.1 create a digital

How can I use the flashback database feature to restore the replicasuard environment after a failover ?, FailoverdataguardThe 11g slave uard standby is cut into the master database. After the test is completed, it is restored to the original standby

Unregister to multiple columns with multiple names and unregister to multiple columns-- Oracle syntax Create table T5 (idnum NUMBER, f1 NUMBER (10, 5), f2 NUMBER (10, 5), f3 NUMBER (10, 5), e1 NUMBER (10, 5), e2 NUMBER (10, 5 ), h1 NUMBER (10, 5),

Oracle Data Pump (expdp) backup reports ORA-39006: internal error, expdpora-39006 in Linux Problem description: Oracle has been using a Data Pump backup, today at the terminal backup suddenly reported ORA-39006: internal error. The data pump

JDBC obtains metadata DatabaseMetaData, databasemetadata Package org. data. jdbc; import java. SQL. connection; import java. SQL. databaseMetaData; import java. SQL. driverManager; import java. SQL. preparedStatement; import java. SQL. resultSet;

MHA online switching and mha Switching In addition to automatic monitoring and switching, MySQL MHA provides online failover, which is mostly used for hardware upgrades and MySQL database migration. This mode provides fast switching and elegant

MySQL obtains discontinuous values. mysql obtains discontinuous values.1. Problems A table is displayed as shown in. In the data, running_number should be a continuity of 5 characters. Obtain the running_number that is disconnected from the

MySql Installation Error A problem occurred recently during mysql installation: 1. Unlike operating systems, deletion and cleanup are also different during installation: Window 7, the following describes how to fully uninstall an ECS instance: 1)

Use PL/SQLDeveloper to import excel data to the database, plsqldeveloper 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

Php implementation method for memcache consistent hash, memcachehashI recently read some distributed articles, so I used php to implement consistent hash to train my hands. In the past, I used the most primitive hash Modulo for distribution, when a

SQL is required. Note chapter 20th to manage transaction processing. SQL is required.20.1 Transaction Processing Transaction processing can be used to maintain the integrity of the database,It ensures that batch SQL operations are either completely