Database Administrator

MySQL "Bind on TCP/IP port: Address already in use" Recently, a MySQL instance has been added to the server where MySQL Enterprise Monitor has been deployed. As a result, the MySQL Enterprise Monitor Instance becomes abnormal and cannot be restarted

Install MySQL database in CentOS Because I want to deploy a Java project on CentOS, this project requires database operations, so the first thing is to install the database! Now I will take you step by step to install the MySQL database. First, in

[MySQL Notes] Powerful SQL optimization tool and powerful MySQL SQL Tool If you have experience using MySQL, you may encounter slow SQL queries in your project. In some scenarios, you can easily locate the problem (for example, when a single table

OGG extract process checkpoint time back to 00:00:00 troubleshooting, checkpoint1. Fault The Extract process (SEXTR01) status is running, but the Lag at Chkpt has reached more than five hours, and the time has been increasing. No new logs are

Redis Research (10)-Redis transactions and survival time, redis transactions I. Transaction Overview Redis transactions are a collection of commands. A transaction is the smallest Execution Unit of Redis like a command, either executed or not

Database usage-oracle bitmap index,-oracle bitmap Index Currently, a large number of indexes are mainly B * Tree indexes. The index structure stores the rowids of key values and key values, which correspond one to one. Bitmap indexes are mainly

Part 1 basics Chapter 2 install MongoDB and basic mongodb Statement: This article is mainly from the book "MongoDB Practice". I want to learn the knowledge and understanding of MongoDB through this book, so I wrote it in my blog post, as recorded in

OPatch reports Prerequisite check "CheckActiveFilesAndExecutables" failed, opatch Prerequisite check "CheckActiveFilesAndExecutables" failed Problem background:When we patch the Optatch database, the system suddenly reports the error

Perform catastrophic recovery-1 and perform disaster-1Perform disaster recovery:[Oracle @ oracle ~] $ Sqlplus/as sysdbaSQL * Plus: Release 10.2.0.5.0-Production on Thu Nov 6 20:23:30 2014Copyright (c) 1982,201 0, Oracle. All Rights

Blood lessons --- ogg must use the latest version, and blood lessons --- ogg must useThis cocould be a Bug 19517566-ie extract abend with OGG-01161 bad column index relating to the extract where the extract was still resolving the old metadata and

SQL Database Study Notes and SQL Database Study Notes Although learning is slow, you need to learn it step by step. Study Notes: 1. SQL statements are case insensitive 2. MySQL requires a semicolon; 3. Used commands: Show databases; // display the

DB2 Materialized View (Materialized Query Tables, MQT), materializedmqt The Materialized View of DB2 MQT is a table defined based on the query results. The data contained in the MQT comes from one or more tables based on the MQT definition, using

Common tools in activeMQ publishing and subscription mode, and activemq tools package com.jms;import java.util.Map;import java.util.concurrent.ConcurrentHashMap;import javax.jms.BytesMessage;import javax.jms.Connection;import

Oracle _ sequence, index, synonym, oracle SynonymZookeeper 1. Sequence1. sequence: database objects that can be used by multiple users to generate unique valuesUnique value automatically providedShared objectIt is mainly used to provide the primary

ORACLE _ create and manage tables, oracle CreationZookeeper ORACLE _ create and manage tables ① Common database objectsTable: A Basic Data Storage set consisting of rows and columns.View: logically related data set extracted from the table.Sequence:

Mysql_ping () and MYSQL_OPT_RECONNECT MySQL server has gone away "error, mysqlgoneawaySource: http://www.felix021.com/blog/read.php? 2102Yesterday @ Zind found my previous blog (modified), which mentioned mysql_ping and MYSQL_OPT_RECONNECT.The

What is statistics and how to collect and view statistics?Concept:Oracle statistical information: it is stored in the data dictionary and describes the object details in the Oracle database from multiple dimensions. CBO uses these statistics to

MySQL full-angle conversion to half-angle, mysql full-angle conversion to half-AnglePreface:When a user entered a fullwidth mobile phone number during registration, the text message system failed to send the text message based on the mobile phone

Understand the internal structure of B * tree index and the internal structure of tree Reprinted please indicate the source: http://write.blog.csdn.net/postedit/40589651 The B-tree index in the Oracle database is like an inverted-long tree, which

Rman and rman backup Rman target/nocatalog The list command is used to LIST the backup information of data.1. List backup sets of data filesList backupset of datafile 'data file name'2. List the tablespace backup informationList backup of tablespace