Database Administrator

Duplicate data read at the REPEATABLE-READ isolation level of MySQL" In MySQL, MVCC is used to implement the REPEATABLE-READ isolation level, because the SELECT operation does not lock the data, other calls can modify the data read by the current

Install and configure MariaDB on RHEL/CentOS MariaDB is an open-source relational database and a MySQL database branch version developed by the community. MariaDB has replaced MySQL as the default database in RHEL/CentOS 7. In this tutorial, we will

Expdp and impdp parameter usage 1. Create a logical directory. This command does not create a real directory in the operating system. It is best to create a directory as an administrator such as system.Create directory dpdata as '/opt ';2. Check the

[Transfer tablespace] use the EXPDP/IMPDP tool's transfer tablespace to complete data migration This article demonstrates how to use the EXPDP/IMPDP tool to completely simulate the process of transferring tablespaces for your reference.Task

Installing Oracle 11g R2 in LinuxI. installation environment Linux Server: CentOS 6.4 64-bit Oracle Server: Oracle 11gR2 64-bitIi. System Requirements Requirements for installing Oracle in Linux System Requirements Description

Oracle RMAN restores the database to different hosts I. RMAN backup content When RMAN is used for full backup, it contains data files, archive logs, control files, parameter files, and backup logs, as shown below: Arch_20160223_08qukp2t_1_1 arch_2016

MongoDB backup and recovery (mongorerstore)MongoDB Data Backup In Mongodb, we use the mongodump command to back up MongoDB data. This command can export all data to a specified directory. The mongodump command can be used to specify the exported

IEE Database Installation Wizard RHEL 5 uses an rpm package to directly install the package and configure the data and cache directory. RHEL 6 uses the tar package + configuration file. This article is a wizard for installing IEE on RHEL 6.Upload

Summary of common JDBC interfaces and summary of jdbc This article mainly introduces common JDBC interfaces. Let's take a look at the specific content below. 1. Driver Interface Each database Driver must implement the Driver interface. When writing

Linux CentOS 7 source code compilation and installation of PostgreSQL9.5, centos7 source code compilation rpm The previous blog recorded the installation of PostgreSQL 9.3 in the form of an rpm package (PostgreSQL 9.3 is installed in Linux CentOS 7 (

Parallel recovery of large oracle transactions leads to database performance degradation-high cpu usage  The rollback of a large transaction has a very high cost, not only locking the required resources And the CPU and IO consumption, especially IO,

How to diagnose job execution failure 1. Check whether the job can be executed.Make sure that the job_queue_processes parameter in init. ora is set to a value greater than 0.Show parameter job_queue_processes 2. Check whether an error occurred

In the previous two slides, I shared with us the role of SET QUOTED_IDENTIFIER and introduced a simple string segmentation function. This time, I will introduce how to find out the types, field sizes, whether it can be blank, whether it is a primary

In large databases, Procedure is often called because of development needs. Procedure development on Oracle and SQLServer varies with syntax. debugging Procedure is not easy on both systems, especially when error processing is performed. Debugging:

A data warehouse needs to obtain different types of data from different data sources, and convert these huge amounts of data into available data for users, to provide data support for enterprise decision-making. This process is often called ETL

Taking the Oracle7.33 database system as an example, when developing a large Oracle database system, based on the characteristics of the project, we conducted some physical design on the database in line with the principles of security and

I often see some people ask, MSSQL occupies too much memory and continues to grow; or it has been set to use memory, but it does not use so much. What is this? First, let's see how MSSQL uses memory. The biggest overhead is generally used for data

This article demonstrates how to use the mysql client program to connect to the database server. Mysql is sometimes called "Terminal Monitor" or "monitoring"). It is an interactive program that allows you to connect to a MySQL server, run the query,

Each database of SQL Server, whether it is a system database master, model, sybsystemprocs, tempdb) or a user database, has its own transaction log, and each database has a syslogs table. Logs record user operations on the database, so if you do not

BKJIA Summary: in the previous article, we saw the performance optimization of the DB2 utility. This time we will focus on the performance considerations for the DB2 concurrent connection. In general, when the number of connections is small, the