Database Administrator

Oracle Syntax:INTERVAL '{integer | integer time_expr | time_expr }'{DAY | HOUR | MINUTE} [(leading_precision)]| SECOND [(leading_precision [, fractional_seconds_precision])]}[TO {DAY | HOUR | MINUTE | SECOND [(fractional_seconds_precision)]}] The

DDS is a copy and disaster recovery software based on Oracle databases. It is a logical application technology that does not require a hardware platform. It can be deployed across platforms for heterogeneous remote disaster tolerance. I. software

[Problem description] How to Control SQLite3 and perform basic database operations when using C to write CGI programs? [Overview] Variable to be created Sqlite3 * db; IntNrow=0,Ncolumn=0; Char **AzResult=NULL; Char *ZErrMsg=0; Char SQL [500];

Show variables like '% character %' After logging on to mysql by default in Linux Mysql> show variables like '% character % '; ------------------------------------------------------| Variable_name | Value | Modify/etc/mysql/my. cnf Add

In Linux, the configuration of MySQL remote access settings is described a lot on the Internet, but the actual operation is still a lot of trouble, record it (Attention should be paid to the red area.). The first step is the same as configuring

The Lag and Lead functions can retrieve the data of the first N rows and the value of the last N rows of the same field in a query. This operation can be achieved through table join for the same table, but LAG and LEAD are more efficient. The lag

You can change a common table to a partition table in the following ways:1. Create a partition table A_NEW, which is the same as the original table;Insert A_NEW SELECT * from;Name Table A A_OLD and name A_NEW;2. Use the previously redefined method!

Strings type The string type is binary secure. Redis strings can contain any data, such as jpg images or serialized objects. From the perspective of internal implementation, the string can be regarded as a byte array, and the maximum value is 1

To count which users are logging on to the database and other purposes, you need to record the information about the database logon and the information about failed attempts to log on to the database, which of the following triggers can be

I,ASM(Automatic Storage Management) reason: ASMYesOracle 10g R2To simplifyOracleA new feature introduced by database management, which isOracleThe volume manager provided by Alibaba Cloud is mainly used to replace the volume manager provided by the

Today, we will describe how to enable IO settings in Oracle. First, check whether the package of asynchronous io has been installed on the operating system. If not, install it through rpm and check the parameter settings of asynchronous io on the

After a week of hard work, I finally completed the Fedora 16 X86_64 system on the new machine. Compared with the Fedora 14 in this book, the current Fedora version feels more beautiful and stable, but it is not a habit to use it. For more

If the directory on the master and backup is different, add the files in the pfile file on both ends. If the directory is the same, add the following files:*. Log_file_name_convert = '/u01/oradata/orcl/', '/u02/oradata/orcl /' *.

Mysql recursive sorting Query Note: producttype sorting table, producttype. Ptype parent node, producttype. Id Primary Key, showTreeNodes (IN rootid INT) function. The parameter is of the starting type. Drop procedure if exists showTreeNodes;

In Oracle 11g, add a disk to an existing disk group. The operation command is "alter diskgroup webdg add disk '/dev/raw/raw4 ';", however, if you use sysdba for connection, an error is returned. ORA-15260: permission denied on ASM disk groupInform

I. Basic Configuration: 1.ToRootLogin, MountLinux isoFile [Root @ Oracle ~] # Hostname Oracle.junjie.com [Root @ oracle ~] # Cat/etc/sysconfig/network NETWORKING = yes NETWORKING_IPV6 = no HOSTNAME = oracle.junjie.com [Root @ oracle ~] # Ifconfig

1. Oracle data export: (1) completely export data from the database bkjia. The database username bkjia and password bkjia are exported to the local E: \ data. dmp. Exp bkjia/bkjia @ bkjia file = E: \ data. dmp full = y (2) export the tables of

MySQL is a widely used relational database. When the data size expands and the importance increases, the reliability and performance of a single database are severely challenged, so there will be a master-slave database, read/write splitting and

When I was reading CU today, I found someone asking about optimize's table optimization problem. It was a long time because of this problem. Today I am free to ask this question, we can use the actual data to show it, so that you can see with your

For RAC, when an Oracle Instance fails, the application has several high-availability technologies to ensure availability. These technologies are transparent to the client, and the client may not be able to perceive the instance failure.1.