Database Administrator

Oracle Foreign keys only have cascade deletion and no Cascade update, but sometimes such functions may be required in the system, so the implementation process is recorded here. There are two constraints in Oracle: latency constraint and non-latency

Basic Information Database Version: Oracle 10.2.0.4 Number of nodes: 2 1. Stop all processes related to oracle, including databases, asm, node application, and crs.1.1 close all processes, Crs_stop-all 2.2 shut down the crs background process and

The redo path is incorrect today, and the standby uard database cannot be open: ORA-01275: The add logfile operation is not allowed when backup file management is automatically performed Let's take a look at the following: Let's take a look at the

There are many methods to implement the High-reliability MySQL solution. Using the built-in replication function of MySQL is the simplest one.The internal replication function of MySQL is implemented between two or more servers by setting the master-

If the not null restriction is added when VARRAY is defined, the element of this VARRAY cannot be NULL. Definition: Create or replace type integer_varrayAs varray (5) of integer not null;/ Then there is a PLSQL block as follows: DECLARE -- Declare

We all know that the controlfile records information about each archivelog. Of course, after deleting these physical files in the OS The archivelog information is still recorded in the controlfile. the logs are displayed visually in the Oracle OEM

The following is my summary and my understanding about Oracle backup: 1. The data block size in Oracle is usually an integer multiple of the OS block size. The database is always available when the data file is directly copied to the backup media

When checking the disk space used by the database files, we found that the undo tablespace used as much as 4 GB this weekend. Up to 24 GB! According to the normal volume of things, it will not grow so fast. Now there are a few GB of memory left on

The most basic method is to create one master node and one or more slave nodes. Each slave node must know the address of the master node.Start the master server:Java code Mongod -- master Start the slave server, where master_address is the

1. Currently, there is only one control file. We plan to add three to ensure security. SQL> select name from v $ controlfile; NAME -------------------------------------------------------------------------------- + DATA/tyolap/controlfile/current.256

User settingsUlimit-SHn 65535Mkdir-p/home/mysql/infobright/Usr/sbin/groupadd mysql/Usr/sbin/useradd-g mysqlCd/usr/local/soft/Download and decompress64-bit SystemWget http://www.infobright.org/downloads/ice/infobright-3.3.1-x86_64-ice.tar.gzTar zxvf

Statement for querying deadlock information in Oracle: Select a. owner, A. object_name, B. xidusn, B. xidslot, B. xidsqn, B. session_id, B. oracle_username, B. OS _user_name, B. process, B. locked_mode, C. machine, C. status, C. server,

The latest mysql versions require cmake compilation and installation. It is estimated that this method will be used in future versions. Therefore, we will record the installation steps and procedures for your reference.Note: This installation is the

The term "View" is too abstract. At first glance, you don't understand what it means, but you don't even know what it means. In fact, you will suddenly realize what it means. The difference between a table and a view is that a table occupies the

My colleague called and told me that the CPU usage of the database is too high and swap is frequently exchanged. I 'd like to take a look at it now. Here, I will record the entire process for your reference and let you provide some comments. $ Topas

1. view the data in the first three rows. If the column alias does not existASClause. The derived column is named 2, which indicates that it is the second column in The result set. Db2 => select name, salary + comm from staff fetch first 3 rows

Set OperationsUsed to merge results of multiple select statements Union deduplicationUnion all unionIntersect IntersectionMinus difference set UnionMerge set A and Set B, but remove the duplicate parts of the Two Sets and sort them.SCOTT @ ora10g>

Common sqlplus commandsWhen an SQL statement is entered, the SQL statement is in the cache of SQLPLUS. The cache is small and only one SQL statement is allowed. When the next SQL statement is entered, the previous SQL statement is overwritten.To

Requirement Description In reports with specific requirements, some layout objects may be displayed or hidden under certain conditions. There are two methods for developers to develop reports in Oracle reports builder. Use Format Trigger for

The following describes how to install the MySQL database: 1. The master and slave servers perform the following operations respectively::1.1 consistent version1.2 initialize the table and start mysql in the background1.3 modify the root password2.