Programmer Group

In ORACLE, there are five ways of Index Lookup paths: INDEX UNIQUE SCAN, INDEX RANGE SCAN, INDEX FULL SCAN, INDEX FAST FULL SCAN, INDEX SKIP SCAN. The following five index access paths are introduced and summarized through some cases. This article is a summary of the knowledge points in this regard, so some places in the article refer to and qu ...

Influxdb provides two ways to integrate data: Continuous Queries (CQ: Continuous Queries) and Retention Policies (RP: Retention Policies). The combination of these two methods can not only preserve the data of a long time ago, but also reduce the system resources occupied by the data on the premise of reducing the accuracy. Generally, continuo ...

(1) In the SQL language, a select-from-where statement is called a query block, and a query block is nested in where or having of another query block, which is called nested query. (2) Creating three data tables CREATE TABLE `person` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(25) DEFAULT NULL, `sex` varchar(45) DEFAULT NU ...

0x00 Packaging Prerequisites This time, it is only encapsulated in the function interface layer, which was originally intended to be encapsulated in business class calls. There are still many knowledge points to review, so it is abandoned. Now let's talk about the guidelines for encapsulating interfaces: 1. Interface single responsibility ...

target 1. Complete database migration 2. Reorganization of database file structure 3. Verify data file integrity Detailed Data Migration Scheme 1. Overview of the migration environment 2. source database Ip:192.168.52.103 Oracle_sid=test Database version Oracle 10g release 2 target database IP:192.168.52 ...

Experience of QL optimization with twists and turns background Recently, I received an SQL tuning task, which performs nearly five seconds in a month of data statistics in the development environment. Originally thought it was a smooth optimization, but I didn't expect that in order to get the best result, it went through twists and turns. ...

Compared with the previous section, go language access to MySql database can be better written, today we will talk about connection pooling. At the same time, it also demonstrates the processing of go language when the table field content is NULL. First, we build a new database, cofoxdb and data table user. Added Administrator Switch tab S ...

Preface: Because of the use of FluentData in recent projects, the access to information is not comprehensive enough, so the Official website The following documents are translated for your reference. Text: Start learning Environmental requirements .NET 4.0. Support database MS SQL Server uses local. NET driver MS SQL Azure uses local. NET ...

grails has been upgraded to version 3.0.9 due to work needs, and needs to configure multiple data sources. grails 2.1's multi-source configuration is relatively simple, but more than 3.0 version of the database configuration changes to application.yml for configuration, how to configure multi-source, Baidu and bing search no answer (forgive me ...

This paper first introduces the installation and basic use of mysql, advanced operation, import and export of MySQL and automatic backup, then introduces the security mode modification password and full text search function of mysql, and finally records the problem set encountered in personal use of mysql. Start installation: sudo apt-get in ...