Database Administrator

Compile and install MySQL 5.6.23 in Ubuntu 14.10 1. installation environment:Ubuntu Server 14.10MySQL-5.6.23.tar.gz 2. install necessary toolsSudo apt-get install make bison g ++ build-essential libncurses5-dev cmake 3. Add a combined user to set

Use DBMS_SCHEDULER package to manage scheduled tasks Read navigation Create a scheduled task: Detailed description of supported task types: Example Manual execution plan Delete plan Dbms_scheduler is a package provided by Oracle to create

Manual Oracle database creation Read navigationDatabase Version:1. Set environment variables and create directories2. Create an initialization parameter file3. Start the instance to nomount to create a database4. run scripts to create dictionaries,

About password-less logon in Oracle and MySQL Password-less logon can simplify the process to a certain extent. It is a good choice if it is password-sensitive but requires access permissions. It is a tangle of passwords and passwords, especially

Oracle Database Help The Oracle Database Help class encapsulates the methods used to connect to the Oracle database, which can be called on other pages without repeated writes. Import java. SQL. Connection;Import java. SQL. DriverManager;Import java.

MySQL In cannot be rewritten using an internal connection The original interview was carried out as an interview question ..What MySQL In uses Exists, which is very slow...The interviewer asked me what to do. The answer was to rewrite it with an

Semi-join in MySQL 1. BackgroundWhat is semi-join?The so-called semi-join refers to the semi-join subquery. When a table finds a matched record in another table, semi-jion returns the record in the first table. In contrast to the conditional join,

Database paging stored procedures, supporting multi-table joint queries, paging stored procedures Database paging stored procedure, supporting multi-table joint Query Create procedure [dbo]. [getInQuiryAllByPage] @ tableNames varchar (5000), --

Oracle internal and external connections, oracle internal connections Inner join: We usually connect tables to display data with matched IDs. SELECT * FROM a, B WHERE a. aid = B. bid only retrieves matched data. Outer connections: Left

Mysql storage engine types, such as MyISAM and InnoDB, and mysqlmyisam For some texts, refer to other blogs or texts.Official explanation: · MyISAM: the default MySQL plug-in storage engine, which is one of the most commonly used storage engines in

SqlServer changtracking and sqlservertracking For DML operations that track database tables, SQLserver 2008 and later provide Change Data Capture and change tracking. Differences Between Change Database capture and tracking changes: Change Data

SQL language and T-SQL language introduction, sqlt-SQL Introduction SQL Introduction Structured Query Language (SQL) is a non-procedural language that processes a record at a time and provides automatic navigation for data. SQL allows you to work on

SQL reads XML fields and sqlxml Fields Recently, we have to migrate data to an old system. This is a tough task. We need to compare the fields of the new and old data tables to migrate the data of the old system to the new system. Although the data

The mybatis column type is invalid, and mybatis is invalid. Project error: [FaultEvent fault = [RPC Fault faultString = "org. springframework. jdbc. uncategorizedSQLException: Error setting null parameter. most JDBC drivers require that the

MYSQL width indicator and MYSQL width indicator 1. In the old version of MySQL 3.22, the single table size of MySQL is 4 GB. At that time, the MySQL storage engine was also the ISAM storage engine. However, when the MyISAM storage engine appears,

Easily understand the principles of the MySQL database lock mechanism, and easily master mysql 1. show processlist: Check the database table status and whether the table is locked; Kill id // kill the locked table ===================================

News system-SQLHelper assistant optimization, news system sqlhelper We used SQLHelper when restructuring our data center, but at that time we only applied it. We knew that using SQLHelper could help us connect to the database, but we still don't

MongoDB BASICS (8) replication Ⅱ-deployment of arbitration nodes, mongodb Arbiter is a mongodb instance in the replica set and does not store data. The arbitration node uses the smallest resource and does not require hardware devices. It cannot

Java memory recovery mechanism and Java memory recovery mechanism In Java, its memory management includes two aspects: Memory Allocation (when a Java object is created) and memory recovery. These two aspects are automatically completed by JVM, this

View MySQL indexes and mysql IndexesMysql> show index from tblname; mysql> show keys from tblname; · Table name. · Non_unique: 0 if the index cannot contain duplicate words. If yes, it is 1. · Key_name index name. · Column serial number in