Database Administrator

Problems encountered during upgrading MySQL 5.1.61 to 5.6.19 in CentOS 6.3 and Their Solutions Environment: MySQL 5.1.61 Operating System: CentOS 6.3 Objective: To upgrade to MySQL 5.6.19 First, yum is not feasible. because the yum source is not

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

Key to enterprise application of NoSQL The discussion about whether NoSQL can be competent for enterprise-level databases is rampant. The focus of attention is that the environment of NoSQL databases is uncertain and changing. Some NoSQL enterprises

Six flashback technologies in Oracle, flashback The Flashback technology is based on the content in the Undo segment, so it is limited by the UNDO_RETENTON parameter.To use the flashback feature, you must enable automatic undo tablespace

Use RMAN to copy RAC + ASM to a single instance + ASM This test copies the dual-node RAC deployed on ASM to the ASM of a single instance. This test is also based on the needs of a project. The drill operations on the virtual machine are hereby

Oracle RAC background process Introduction There are more processes in the Oracle RAC database than in a single instance database. These processes are unique to RAC and are set to implement cluster database functions. This article will introduce RAC-

Permission handling for installing Oracle 11g OS in Win7 64bit In general, we choose to install Oracle databases in traditional server operating systems such as Linux and AIX. Even in Windows, server versions such as 2008 and 2012 are used as the

Generate awr report and awr report References: Http://343766868.blog.163.com/blog/static/48314056201110124513396/Overview Oracle stores critical system statistics and load information at a certain frequency to generate snapshots. All snapshots are

In sqlplus, how does one save all your operations and Result Records to your specified file? [In sqlplus operations, we often want to record the SQL statements we write and modify the log or result information] [First] You must connect to the oralce

Java statements for database operations are prone to errors. java statements are prone to errors. Let's first look at the following statement String sqlString = "select * from petMessage where petName = '" + pet. getPetName () + "';"; The preceding

ORA-21561, ORA-15055, ORA-25253 lead to DG slave database cannot apply archive, ora-21561ora-15055Yesterday I went to a customer to do inspection, by the way, to see whether the last build of the RAC-DG environment is normal, do not see do not know,

Practice: Create shell scripts for tablespace in oracle, oracleshell #! /Bin/bash # ocpyang@126.com # create tablespaceif [$ #-ne 2]; then echo "Usage: $0 TABLESPACE_NAME TABLESPACE_SIZE" exit 1fi # configure oracle env: about oracle envs, username

Oracle 11g RAC manually uninstall grid, no deinstall, griddeinstall1. log on to the ORACLE_HOME page of the grid as the root user. [Root @ db01] # source/home/grid/. bash_profile[Root @ db01] # cd $ ORACLE_HOME/crs/install/ 2. Execute the

An example of SQL SERVER database attack Recently, it was found that the SERVER on the internet is inexplicably restarted. This SERVER currently mainly starts the IIS and SQL SERVER services. Remote Login, found that the system reaction is slow,

The agent slave Database Host cannot be found when the slave database is created in EM12c, And the em12cagent Symptom:When you use EM12cR4 to create a slave database, you cannot find the slave Database Host, but the slave Database Host

BBED marks Bad blocks and fixes bad blocks. Create a test table: ZBDBA@orcl11g>select * from

PB + ms SQL + trigger must note that pbsql Note the following before using PB + ms SQL + triggers: If the trigger has more than two returned values, for example, two update statements, it is misjudged that the data has changed and the disk is not

MySQL trigger learning, mysql triggerTrigger: a special type of thing that can monitor certain data operations and trigger related operations (insert, update, and delete). Some data changes in the table, it is expected that other data changes may

SQL Execution time, SQL Execution Enable SQL Execution time statisticsSet timing on;   Check whether SQL statements with long execution time exist.Select a. sid, B. SQL _textFrom v $ session a, v $ sqlarea BWhere a. SQL _hash_value = B.

Is it true that Select * does not go through the Index ?, Select Index The index indicates that the execution plan of the SQL statement uses 1. Clustered index search 2. index search, and the where clause must be included in the query