Database Administrator

How to downgrade an Oracle database from 11.2 to a previous version This document can be used to downgrade the upgraded database from Oracle 11gR2 to the following guidelines and checklists: Oracle 10gR1, Oracle 10gR2, and Oracle 11gR1. This

Xtrabackup backup of large databases (full backup and Incremental Backup) Xtrabackup Xtrabackup is a free Database Hot Backup Software open source by percona. It can back up InnoDB databases and XtraDB storage engine databases in non-blocking ways

Implement RowNumber () Over (Partition by) and qlikviewrownumber in SQL Server in QlikView This is often the case when field A has many duplicate values, but the values in field B are unique After grouping by field A. Therefore, SELECT, when field B

IT Ninja Turtles oracle connect by usage review, Ninja Turtles oracle First use the emp table of scott.The emp table has one field: empno (employee ID) and mgr (Superior manager ID)Below are all the data in the table 1 select *from emp

Database Link of IT Ninja Turtles: database of Ninja Turtles -CREATE public database link test_link connect to scott identified by tiger using '(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP) (HOST = 127.0.0.1) (PORT = 1521) (CONNECT_DATA

MySQL changes the table storage engine, MySQL storage engineMySQL provides multiple database storage engines that store and extract data from MySQL databases. Different storage engines have different features. Sometimes you may need to convert an

Mysql Performance Check script-mysql Performance Check script #! /Bin/sh# Ocpyang@126.com Export black = '\ 033 [0m'Export boldblack = '\ 033 [1; 0m'Export red = '\ 033 [31m'Export boldred = '\ 033 [1; 31m'Export green = '\ 033 [32m'Export boldgreen

I. Check hardware requirements:1. Memory:#/Usr/contrib/bin/machinfo | grep-I MemorySwap:1 GB-2 GB 1.5 times the size of the RAM2 GB-16 GB Equal to the size of the RAMMore than 16 GB 16 GBView the swap size:#/Usr/sbin/swapinfo-2. Disk Space:/Tmp

Simplify the installation of Oracle Database11g on Oracle Linux 5 Directory 1. Introduction of Oracle-validated RPM for oracle Linux2. Install oracle-validated RPM3. Configure the Directory and set the group and permissions of the directory owner4.

PostgreSQL code analysis, query optimization, canonicalize_qual, postgresql Here, we have finished sorting out the part of the regular expression. The reading order is as follows: I. PostgreSQL code analysis, query optimization,

Basic knowledge of SQL injection and basic knowledge of SQL Injection What is SQL Injection) The so-called SQL injection attack means that an attacker inserts an SQL command into the input field of a Web form or the query string requested by the

Detailed description of distributed algorithms and NoSQL algorithms in nosql Databases Today, we will study some distributed strategies, such as replication in fault detection. These strategies are marked in italics and divided into three parts:

Mongodb advanced 3: mongodb management and mongodb advanced management Http://blog.csdn.net/stronglyh/article/details/46827141 Usually, there are many win development environments, but the production environment should be put on unix. I.

I. Basic Introduction SQLite is a self-contained, serverless, zero-configuration, and transactional relational database engine. Because it is very small, it can also be built into your application as an embedded database. SQLite is used in Solaris 1

To be continued ...... To be continued ...... To be continued ...... To be continued ...... Col tablespace_name for a15Col segment_name for a15Col segment_type for a15 Select segment_name, segment_type, tablespace_name, extents, bytes/1024 KB from

The SQL statement is as follows:Select distinct cp. name AS cp_name, c. name AS category_name, t. name AS type_name FROM g LEFT JOIN  cp ON cp.id = g.cp_id AND cp.deleted = 0 LEFT JOIN  c ON c.id = g.category_id AND c.deleted = 0 LEFT JOIN  t ON

When the database needs to recover the media, in order to ensure that the database can smoothly perform the recovery process, restore the database to the current state. All we need to do is verify! What is verification? Of course, it is to verify

PostgreSQL tutorial (10): Performance Improvement tips and postgresql Performance Improvement 1. Use EXPLAIN: PostgreSQL generates a query plan for each query, because selecting the correct query path has a critical impact on performance. PostgreSQL

According to Microsoft's official message, SQL Server 2014, the next database platform version, will be released by the end of this year. It will include the table-level memory OLTP function, unlike other memory databases, this feature eliminates

The SQL Server Client Configuration tool is used to configure the client tool (except the DOS-based client tool) so that it can successfully communicate with SQL Server. This program should be run after the client tool is loaded. In most cases, you