Database Administrator

Dangers of slow query in MySQL Databases 1. When a slow query occurs in a MySQL database, it is dangerous. Other DDL operations may cause the entire database to wait. It can be divided into the following situations: When a table is a MyiSAM table,

Conversion of RR isolation level to RC isolation level in MySQL First understand the difference between RR (REPEATABLE-READ) and RC (READ-COMMITTED. The RR isolation level adds a gap lock, which avoids Phantom reads and prevents repeated reads, so

Oracle Dual table details 1. Use of DUAL tablesDual is an existing table in Oracle that can be read by any user. It is often used in Select statement blocks without a target table.-- View the current connected userSQL> select user from dual;USER-----

Install PostGIS in the source code of RedHat7 This article describes how to install and use PostGIS in RedHat7 environment.1. PostgreSQL1.1 install PostgreSQL in yum This is relatively simple and can be directly installed using yum. $ sudo yum

Principles and experiments of Oracle foreign key index creation In the project, we require that all tables with a primary-child relationship use foreign key constraints to ensure the correct relationship between the primary and child tables. We do

Oracle GoldenGate introduction and installation configuration tutorial Introduction to Oracle GoldenGate GoldenGate is a log-Based Structured Data replication software. GoldenGate can capture, transform, and deliver a large amount of transaction

SpringBoot unofficial tutorials | Article 4: Integrating JPA and springbootjpa in SpringBoot Reprinted please indicate the source:Http://blog.csdn.net/forezp/article/details/70545038This article is from Fang zhipeng's blog JPA stands for Java

Implementation of multiple parameters in PrepareStatement SQL statement in, The following is the process of exploring the SQL statement with PrepareStatement pre-compiling where condition as in today. Only the fourth method is implemented in the

PostgreSQL Partition Table (partitioning), postgresql Partition Table PostgreSQL has a very useful function, partition table, or partitioning. When a TABLE has many records, tens of millions or even more records, we need to split it into subtables.

You cannot read the list of previously registered servers on this system. Please register your server again in the "registered servers" window, and then register again in the window Environment: Server System: Database Version: Microsoft SQL Server

Lesson 4 MongoDB Data Query (1): mongodb Data Query1. Course outlineThis course mainly describes MongoDB Data Query related content, including the introduction and use of the find function, query operator introduction and use, embedded document

MyISAM index implementation The MyISAM engine uses B + Tree as the index structure. The data domain of the leaf node stores the data record address. Is the principle of MyISAM index: Figure 8 There are three columns in the table. If we use Col1

I have briefly introduced how to emulate Java in SQL? The implementation scheme that replaces the parameter location, in programming and development, we will implement some strange simple and complex ideas with our own programming concepts, every

When talking about Hadoop, we have to mention Lucene and Nutch. Lucene is not an application, but a pure Java high-performance full-text index engine toolkit. It can be easily embedded into various practical applications for full-text

If you have moved data from or out of SQL Server, you can now use the data transmission service tool of Microsoft or Microsoft. DTS is an ETL Tool (abbreviated for extraction, transmission, and loading). It allows database administrators to create a

Since 1970s, due to the development of computer network communication and the needs of geographically dispersed companies, groups and organizations for more extensive database application, distributed Database systems have been developed based on

A database is a shared resource used by multiple users. When multiple users access data concurrently, multiple transactions can access the same data simultaneously in the database. If concurrent operations are not controlled, incorrect data may be

I made a C # And Oracle system, and it was really troublesome to install an Oracle client on each client. So I searched the internet and checked whether there was a method for not installing the client, oracle has long thought of this problem. He

Oracle Database is one of the most complex databases so far. This complexity allows Oracle databases to meet various requirements of enterprises. However, most of the time, the database administrator has some skills to simplify database maintenance.

As the amount of data is constantly increasing, the CPU is constantly strong, and the dual-core and quad-core features are constantly changing, a time-to-space optimization technology should become increasingly popular. Therefore, Data Compression