Database Administrator

After 10 Gb of Oracle, two features OFA and OMF are introduced in terms of directory structure and file management. OFA (Oracle Flexiable Architecture) is a feature of directory structure constraints. The directory structure distribution of

Oracle obtains the number of weeks and the start and end dates of each week. -- Obtain the start date and end date of the week of the last year, starting from Sunday.Select'20140901' | Sunday. the_week, decode (sign (Sunday. the_day-saturday.the_day)

Obtaining the Oracle SQL Execution Plan and viewing the execution plan are the basic skills to master and judge the database performance. The following example describes how to view SQL Execution plans: There are basically the following methods: 1.

In this tutorial, we will create a MongoDB cluster with three nodes. The first node is the master node, the second node is the Failover node, and the third node is the arbitration node. 1. Install Mongo and set the configuration file Install three

1. Create an External table using datapump. The data comes from an internal entity table. -- First create the scott. countries entity table for experiment SQL> create table scott. countries ( 2 country_id number, 3 country_name varchar2 (30 ), 4

O & M Engineers deployed a set of Oracle (Database not built) on an IBM P750 (AIX6.1), allowing me to perform a disaster tolerance for a commercial database with its DG. I deployed the DG following the normal steps. 1. Start log recovery in the

1. Previously, the control file was backed up and recovered using the backup control file. (1) backup control file (2) shut down the database and delete the control file. The simulated control file is missing. (3) database startup Error (4)

At work today, my colleagues mentioned how to obtain the space occupied by the LOB in a table. We usually use syscat. tables queries information such as fpages and npages In the table, but this does not separate the common field from the LOB field.

Oracle sometimes requires a large amount of test data. It is very slow and difficult to use a stored procedure. For example, assume that table A is associated with table B, and B _id is a_id. The table fields are as follows, Table: A_id

Lab requirement: Build a mysql Graphics Management Tool on the server Linux: CentOS 6.5 1. Simple deployment of LAMP Platform # Yum-y install httpd mysql-server php-mysql php-pdo # Rpm-ivh php-mbstring-5.3.3-26.el6.x86_64.rpm // this package is not

MongoDB has been widely used as a NoSQL Database in recent years. More and more enterprises are trying to use MongoDB instead of the original Database. MongoDB also performs well in clusters, sharding, and replication. I will introduce various

Environment OS $ Cat/etc/RedHat-releaseRed Hat Enterprise Linux Server release 5.5 (Tikanga)$ Uname-Linux yozhan1.Oracle.com 2.6.18-194. el5 #1 SMP Tue Mar 16 21:52:39 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux Db 2-node rac 1 Oracle Database 11g

Essential for installing MySQL with yum in CentOS 6.5 Step 2. Install mysql in yum[Root @ stonex ~] # Yum-y install mysql-serverInstallation result:Installed:Mysql-server.x86_64. 1.73-3. el6_5Dependency Installed:Mysql. x86_64. 1.73-3. el6_5

There are many ways to view execution plans. I will introduce them one by one in my blog in the future. This article describes the first method. You can use the explain plan command to view the execution plan. 1. log on to the database with an hr

1. Current database environment:Dual-node Oracle linux 5.4 RACGrid software 11.2.0.4Oracle software 11.2.0.4OPatch Version 11.2.0.3.4   2. Download OPatch  Download 11.2.0.4.1 Patch: 17478514P17478514_112040_Linux-x86-64.zip  According to the psu

The MySQL5.6 script is compiled and installed in the source code package. Two MySQL databases are installed on one machine. The port, installation path, and socket file location are specified during compilation. The installed MySQL installation file

Generally reported ORA-00054, it is likely that the object is locked, this error is generally "the resource is busy, but the specified way to obtain resources in NOWAIT, or timeout failure ", the solution is as follows: 1. query which objects are

If you simply use the following SQL statement, failure may be returned. The cause of failure is that the data table already exists. Create table sales3 (id NUMERIC, sale_date datetime not null)PARTITION by range (TO_DAYS (sale_date ))(PARTITION

Accidental data deletion is a "low-level error" that is often encountered by junior O & M personnel. Some experienced veterans sometimes get lost when they are tired and calm ". Once a data file is deleted by mistake, restoring the database with the

In the Oracle environment, PL/SQL is the best way for us to implement business logic, and it is also the best language to combine with the Oracle database itself. Using PL/SQL itself can greatly improve our work efficiency. From the very beginning