Database Administrator

Starting from 10 Gb, Oracle began to provide Shrink commands. If our tablespace supports automatic segment space management (ASSM), we can use this feature to narrow down the segment, that is, reduce the HWM. Here we need to emphasize that this new 1

Many of my friends may have encountered this situation. When regularly clearing Oracle log folders on UNIX/Linux, they may delete trace files that are still open by background processes, that is, some background processes keep holding these

In the company's project, if you need to retrieve data from the databases of other systems for statistical analysis, you should use Oracle's ODI tool for data extraction, however, the database users provided by the other party do not have any

Platform: RedHat Linux 9.0MySQL version: MySQL 5.0.4 Install MySQL source code: # Groupadd mysql# Useradd-g mysql# Tar zxvf mysql-5.0.41.tar.gz# Cd mysql-5.0.41#. /Configure -- prefix =/usr/local/mysql -- enable-thread-safe-client --

The company took over a project. I had no experience with the AIX operating system, and I was able to handle this project by someone who installed 9iRAC a few years ago. Although I have been dealing with RAC over the past few years, I have not

Installation environment: Ubuntu 10.04-desktop-i386 and PostgreSQL 8.4 Installation steps: 1. Install PostgreSQL Enter the following command Sudo apt-get install postgresql The system prompts you to install the required disk space. Enter "y". The

1. Default Processing Oracle considers null as the maximum value by default in Order by, so if it is ASC in ascending Order, it is placed at the end, and DESC in descending Order is placed at the top. 2. Use the nvl Function The nvl function can

For large databases, Oracle occupies a very large disk space, master the database users and tables that occupy a lot of disk space to kill, and increase the situation, you can easily maintain and expand the disk system in the future. The usage of

Set an auto-increment primary key for a table in the project today Mysql> alter table 'users' CHANGE 'id''' id' INT (11) not null AUTO_INCREMENT; ERROR 1062 (23000): Duplicate entry '1' for key 1 The original data in the table is as follows:+ ----

I. OS Authentication 1.1 Introduction to OS Authentication After Oracle is installed, OS authentication is enabled by default. The OS authentication mentioned here refers to the server-side OS authentication. OS authentication means that the user

How does navicat import SQL files? Tools-data transmission-Files How does navicat import SQL files? Navicat 8,Click the one that runs the SQL file. How can I import a local SQL database file to a mysql database? How can I use Navicat for MySQL?

When mybatis inserts a comma-containing value into mysql, the following error occurs: mybatismysqlAn error is returned when mybatis inserts data such as "11, 22, 33" into mysql. The cause of the error is that I joined the SQL statement with the

Detailed process of restarting the Oracle 11G worker uard production environment, 11 gworker uardScenario: restart the database, do not restart the linux system, so you do not need to consider listening programs,# Linux input lsnrctl start1. Close

PostgreSql Partition + Hibernate Insert, postgresqlinsert Unlike Oracle, PostgreSQL needs to manually control partition rule triggers. Step 1: Create a partition Create table table_partition_1 (CHECK partition_column criteria) INHENRITS (table)Step 2

Super powerful: Use case... when... then... else... end condition query (different from where) in SQL commands and type conversion Case... when... then... else... end is before from. You can change the value of a field in the record and cannot

In databases, we often use SQL statements to perform simple statistical sorting on tables. For date fields, we can simply order them. For complex operations, you can perform group and order by year, month, and day of the date. Group by year,

8. View the Exhibit and examine the structure of the MERs table.Which two tasks wowould require subqueries or joins to be executed in a single statement? (Choose two .) (Question: A MERs table is provided for the question, asking which two tasks

11. View the Exhibit and examine the structure of the PRODUCTS table.All products have a list price.You issue the following command to display the total price of each product after a discount of 25% and atax of 15% are applied on it. freight charges

The differences between mysql semi-synchronous replication and asynchronous replication are shown in the preceding architecture diagram: when mysql asynchronous replication occurs, after the Mysql Master Server transfers its Binary Log through the

Reprinted please indicate the source http://blog.csdn.net/guoyjoe/article/details/30965303 The experiment steps are as follows: 1. Use rman to back up the entire database Recovery Manager: Release 11.2.0.3.0 - Production on Sun Jun 8 15:30:35