Database Administrator

PostgreSQL9 connection information to the database To connect to the database, sql9 must provide the following parameters: Host or host address, port number, database instance name, user name, and user password. When you log on to the server, you

Listparts of Oracle Functions Recently, I found an interesting Oracle function that can splice column values. Next, let's take a look at its specific usage. Usage: The official document explains its role as follows: For a specified

MongoDB common optimization settings in Linux Below are some common optimization settings recommended by MongoDB. Selecting an appropriate parameter value in the production environment, such as the preread value and the number of default file

Disable task execution using the DBMS_STAT Function Use the following statements to view SQL statements with large physical reads Select executions,Disk_reads,Buffer_gets,Round (buffer_gets-disk_reads)/buffer_gets, 2) Hit_radio,Round

Oracle client simple connection error ORA-12154, TNS-03505 Environment:Server: RHEL6.5 + Oracle Server 11.2.0.4Client: Win2003 + Oracle Client 10.2.0.11. symptom 2. Troubleshooting 3. Solve the Problem 1. symptom The Oracle database is installed on

Summary of physical DG Master/Slave switchover Environment check Check parameter file configuration of two RAC SQL> show parameter spfile; SQL> show parameter fal; Lsnrctl status Tnsping view the connectivity of TNS To use RAC as the slave database,

Two Oracle deadlock solutions for instances About deadlocks in databases. If you encounter a problem in the application, you will not hesitate to transfer it to the DBA. However, from the current deadlock issue, it is basically the same as the

Mysql Character Set and mysql Character SetThe character set defines the character encoding method. ASCII, GBK, and UTF8 character sets are common. All character sets are compatible with the ASCII character set. Character Set Is negative

Oracle pagination for tables without primary keys and Oracle primary key tables Generally, for tables with a primary key that can be used for unique table recognition, we can use the primary key and rownum for implementation. For example: Select

Powerdesigner 16.5 View display, powerdesigner16.5 At noon today, in order to explain the drawing, we turned off toolbox and object brower. It took us one hour to find toolbox. 1. object brower display Use the shortcut key ALT + 0 2. toolbox

Rapid deployment of Zabbix Server and MPM (monitor for mysql), zabbixmpm1. Preface zabbix, as a free open-source monitoring software, is increasingly popular among it o & M personnel for its ease of configuration management and visualized views,

Error code: 1247 Reference 'starttime' not supported (forward reference in item list), 1247 startTime 1. Error description 1 queries executed, 0 success, 1 errors, 0 warnings query: SELECT. createUserId AS typeId, (select count (c. id) FROM

MongoDB sharding algorithm, mongodbsharding There are two main types: range division by numerical values and hash, which are somewhat similar to the memcached cluster mechanism. The following table compares the advantages and disadvantages

MySQL Chinese garbled solutions, mysql Chinese garbledTest environment: the server and client are both win7. the MySql database and table character set are UTF-8, and the field character set is consistent with the table. 1. Solve the garbled problem

Redis data type -- List, redis -- list The Redis list is a simple string list sorted by insertion order. You can add an element to the header (left) or tail (right) of the list) The LPUSH command inserts a new element into the header, Insert a new

ERROR 1130: Host ''is not allowed to connect to thisMySQL server, 1130 thismysqlOne user asked for help today, saying that PHPmyadmin can connect to the database normally. An error is reported when sqlyog is used: ERROR 1130: Host '2017. 27.214.1

Use the query method to obtain the value of the xml node, queryxml DECLARE @result xmlSET @result='17953736-852b-e511-80cc-0050568e38e0contacttrue'SELECT @result.query('declare namespace s="http://schemas.xmlsoap.org/soap/envelope/";

MongoDB modifies and deletes the domain attribute instance of a document. MongoDB modifies or deletes a file's domain attribute instance During website development, the initial design may be unreasonable or the business changes in the future

Database statement-based table creation, data table copying, and statement copying1. Database tabulation statements Create table tb_People (id integer primary key, Name varchar (255), Sex varchar (255 ))2. Copy data tables from the same database

MySQL command line login, mysql Command LineEnvironment IntroductionOS: CentOS6.X & Win2003 & Win2008MySQL version: 5.5.xIn addition to common MySQL management tools, MySQL client command line tools are often used.1. Install the command line tool in