Database Administrator

Alter system archive log current/all/switch logfile Alter system switch logfile;Force log switching is performed on the current instance in a single instance database or RAC to archive the current redo log. If automatic archiving is not enabled

MySQL database Event Scheduling) The event scheduler in MySQL can regularly add, delete, and execute operations on the database, which is equivalent to a temporary trigger in the database. It is the same as the execution plan task in Linux, which

PL/SQL storage functions and stored procedures Oracle provides the ability to store PL/SQL programs in databases and run them anywhere. This is called a stored procedure or function.Procedures and functions are collectively referred to as PL/SQL

Change the MySQL root Password from null to 123456 Requirement: Change the MySQL root Password from null to 123456. Use mysqladmin Mysqladmin-u root-p password mypasswd After entering this command, enter the original root password (empty), and

Using Keepalived to build master-master MySQL Replication Overview: MySQL-HA has many implementation solutions. It is common to use master + keepalived to implement MySQL-HA. The two MySQL instances have a master-slave relationship and use

Alex's Hadoop cainiao Tutorial: 7th Sqoop2 import tutorial, hadoopsqoop2 For details about the installation and jdbc driver preparation, refer to section 6th. Now I will use an example to explain how to use sqoop2.Data Preparation There is a mysql

Project error due to Oracle 10g empty table export failure -- the table or view does not exist, oracle10 g View This afternoon, the data in the remote database is exported and imported to the local database. After the deployed project connects to

The SQL statement for data deletion and the SQL statement for data deletion No matter whether you are a new college student or a veteran who has been fighting in the software field for many years, as long as you mention the SQL statements used to

Inner join on, left join on, right join on, innerjoin 1. Definition: Inner join: only records with equal join fields in two tables are returned. Left join: returns records that include all records in the left table and join fields in the right table.

Oracle analysis function PERCENTILE_CONT, percentile Function Query the salaries of people with the salary distribution of 25%, 50%, and 75% in each department. percent_rank () is the relative position in the ranking. Create table EMP(Empno number (4

[MongoDB] uses shell in Mongodb to achieve dynamic interaction with javascript. mongodbshell The use of mongodb shell to execute scripts is a bit omitted in previous articles; now I will add a supplement to this blog;1. input the script file in the

C3p0 connection pool template, A connection pool is a technology used to create and manage a connection buffer pool. These connections are ready for use by any thread that needs them. Now I am creating a template for the p3c0 connection pool. First,

The host SHUTDOWN experiment fails to be shut down normally due to host commands. SHUTDOWN has the following parameters: SHUTDOWN NORMAL: NORMAL is also the default clause, and the execution condition is No new connections are allowed after the

What is a cursor? I. Tutorial Purpose 1. Master the methods and steps for creating a cursor; 2. Learn how to use the cursor; Ii. experiment content 1. Create a cursor; 2. How to Use the cursor. Iii. Experiment steps 1. Create a cursor. 1)

Innobackupex full backup database, innobackupex For MySQL Database Hot backup, xtrabackup is the best choice except MySQL enterprise backup. This tool provides Hot Backup Based on the innodb Storage engine, supports full, Incremental backup, partial

Oracle Development Series (iii) table access by index rowid you do not know the INDEX back TABLE, rowid back TABLE1 Introduction Recently, the system often prompts a problem where the SQL query time is too long. After reading it, it is an SQL

Usage of the UNIQUE constraints (UNIQUE Constraint) in Oracle, uniqueconstraint Oracle | PL/SQL Unique index (Unique Constraint) Usage1 goal The following example shows how to create, delete, disable, and use uniqueness constraints. 2. What is a

My experience on ORACLE Data locks, my experience on oraclePart of the post content is for the attachments in The Post (a warrior's understanding about the lock), Understanding/question,Before reading this post, read this article.First, let's talk

General framework of Oracle, Oracle framework The physical structure of Oracle includes parameter files, control files, data files, redo log files, archive files, and password files. 1.1 parameter file This includes a large number of settings that

Solution for modifying uuid in Vboxmanage: vboxmanageuuid My environment: Virtualbox 4.3.10 r93012 Operating System: win7   Problem: a uuid conflict is prompted when Virtualbox uses the copied Virtual Disk: Because a hard disk with uuid ''already