Database Administrator

Summary of Datapump data migration practices Although a lot of data migration projects have been put into practice, some small differences may make a big difference in the entire data migration solution. Data is the core lifeblood of the system.

Ubuntu 12.04 PostgreSQL-9.1 online installation and configuration details Note:I log on to the terminal using a root user. If it is not a root user, add "sudo" before the command, you know... Step 1: Install Postgresql in Ubuntu1. Use apt-get

High MySQL Availability Based on MHA and Galera Cluster MHA: Master HA is an open-source MySQL high-availability program. It provides the automatic master failover function for the MySQL Master-slave replication architecture. When MHA detects a

The Oracle Database verifies whether the imported metadata of IMP overwrites the historical table data. Scenario: When imp imports data, the final trigger reports an error and exits without importing stored procedures, triggers, and functions.Now

Detailed description of mysqlbinlog Based on Log Recovery If a large number of binary logs are generated every day and these logs are not cleared for a long time, the disk space will be greatly wasted. Therefore, regular log cleaning is an important

Connection failure due to Redis high concurrency When ELK collected logs today, it found that the collection failed, looked for various reasons, and finally found an error in the redis log:[2, 2489] 02 Jun 10:43:42 # Error allocating resoures for

MySQL basic learning Summary1. Basic concepts of MySQL The logical architecture of mysql is as follows: Each client connection will have a thread in the server, and the query of this connection will only be executed in this separate thread. MySQL

RAC local data file migration to ASM method-non-archive Mode Reference: How to migrate RAC local data files to ASM System Environment: rhel6.2 _ x64 + Oracle RAC11g Procedure:1. Non-archive ModeSQL> archive log list;Database log mode No Archive

MySQL-5.6.x binary version installation record I. Operating System installation environment 1. Operating System: CentOS 6.7 x86_64. the preparation process of the basic operating system environment is skipped.2. Binary MySQL version:

Solution for ORA-01033 due to accidental deletion of tablespace files This type of problem is usually caused by improper tablespace operations.Solution: SQL * Plus cannot be connected. The following error is displayed:ORA-01033: Oracle

MySQL 5.6.29 source code compilation and installation recordsMySQL 5.6.29 source code compilation and installation record 1. installation environment 1. Operating System: CentOS 6.7 x86_64 # Yum install make cmake gcc-c ++ gcc-g77 flex bison file

Profiling oerr commands in Oracle The commands in Oralce are very rich. The oerr command is a good auxiliary tool. Many error codes that do not seem to have an eyebrow purpose can help DBAs quickly identify the cause of the problem, we don't need to

Changing the Oracle user password will never expire Changing the Oracle user password will never expire 1. Check the user's proifle, which is generally default: SQL> SELECT username, PROFILE FROM dba_users; 2. view the password validity period

Virtual indexes for Oracle Performance Optimization A virtual index is a pseudo index defined in the data dictionary, but there is no relevant index segment. The purpose of a virtual index is to simulate the storage of indexes, instead of creating a

Migrate MySQL database data to SQL Server Recently, due to work requirements, it is relatively simple to migrate a mysql database to sqlserver, which is only a data migration task. For mysql migration to sqlserver, we need to use the mysql odbc

Oracle manual fixed SQL Execution Plan During the O & M process, we often encounter Oracle CBO selection rather than the expected execution plan due to changes in data and statistics of Oracle, the following is a record of the manual execution plan.

Compile and install MySQL5.7.9 from Linux source code I. Environment preparation: I have tried the following environments:1. Minimize the default installation of CentOS6.7 minimal images;2. RedHat6.5 install the basic DVD server;3. Other Linux

Migrate uard to a single machine in RAC Environment Environment Description: Oracle Version: 11.2.0.3.0Primary end:For dual-node RAC, scan uses DNS resolution to run two instances (JSTDB & PAYDB)Standby end:Standalone Federation uard 1. Set the

The skip_constraint_errors option of Oracle impdp skips the unique constraint error. In the past, impdp imported to an existing table has a unique index, and the data to be imported has a unique conflict with the current data. the general solution

Ubuntu 12.04 64-bit compilation and installation of MySQL 5.5.29 Step 1:Go to the official mysql website and go down to compile the source code package.Mysql Website: www.mysql.comDownloads (MySQL Community Server)Download the version, select source