Database Administrator

Standard installation of MySQL binary files Demo Environment Operating System: CentOS 6.7 (64-bit) Binary Package: mysql-5.6.30-linux-glibc2.5-x86_64.tar.gz MySQL: http://dev.mysql.com/downloads/ 1. Download MySQL # Mkdir/root/mysql # Cd/root/mysql #

XtraBackup enables MySQL to redo master-slave replication without stopping services You can use mysqldump to implement MySQL master-slave synchronization without stopping services, but this efficiency is relatively low. XtraBackup is used to achieve

MySQL-5.6.x binary version installation record I. Operating System installation environment 1. Operating System: CentOS 6.7 x86_64. the preparation process of the basic operating system environment is skipped.2. Binary MySQL version:

Automatic parallelism in Oracle 11gR2 In Oracle 11.2.0.2, automatic parallelism can be used only when I/O statistics are collected. When parallel_degree_policy is set to auto, the Oracle database determines whether to use Parallelism Based on the

MongoDB Limit and Skip MethodsMongoDB Limit () method If you need to read a specified number of data records in MongoDB, you can use the Limit Method of MongoDB and the limit () method to accept a number parameter, which specifies the number of

MySQL monitoring tool-orzdba Source code: http://code.taobao.org/p/orzdba/src/trunk/[Root @ bkjia servers] # chmod + x orzdbaConfigure your MySQL verification information in line 1 of the Code: username, password, socket, host, port[Root @ bkjia

Solve the Problem of invalid Oracle environment variables in Linux When you maintain the Oracle database in Linux today, view the listener status and execute # Lsnrctl status Error:-bash: lsnrctl: command not found. This is not the case in the

Create external table in Oracle Oracle db allows you to query External tables in read-only mode. External tables can be stored on any storage device that can be read by oracle databases. The content of external tables is not saved in the database.

Considerations when enabling full log query in MySQL 5.6 Today, because I want to query the call of an SQL statement, I started the full query log in production and thought that I only need to write it like this in my. cnf: Log =/home/logs/mysql.

DataGuard bug in adding temporary data files One environment is Oracle 10gR2, with one master node and two slave nodes. Because the 10 Gb slave database is not active, we will open the corresponding window time when there are some query requirements.

Export error EXP-00091 with exp Run the following command to export data: Exp user/pwd @ db file =/home/a. dmp log =/home/a. log Output The following information, which contains error prompts for some EXP-00091: .. Exporting table T 0 rows

Oracle 12C multi-index with the same column In Oracle 12c, Oracle provides the ability to create different indexes on the columns of the same table for SQL Performance Optimization, but only one index is visible. The following is an exampleConnected:

Oracle 12C TRUNCATE TABLE CASCADE The truncate table cascade statement is provided in Oracle 12c to delete the association when the TABLE has a primary foreign key relationship and is cleared. The following is a demonstration. 1. Prepare the test

Analyze and solve the problem that MRP cannot be started in DataGuard I have a dedicated uard environment on hand, because it has been useless for some days. As a result, I was suddenly prepared to start learning, and suddenly found that after I

What are the integrity constraints of database design? What are the integrity constraints of database design? Here are four aspects: 1. Domain integrity:The columns in the database table must meet certain data types or constraints. The

Error code: 1050 Table 'emp' already exists, empexists 1. Error description 1 queries executed, 0 success, 1 errors, 0 warnings query: create table emp (id int (8) primary key not null, ename varchar (20) not null, eage int (3), esex varchar (2)

Mysql exports the query result to the csv method, mysqlcsv To export the mysql query result as csv, you can connect to mysql using php to execute the query, and then use php to generate the csv format of the returned query result for export.

Fastdb's Chinese Character truncation error In Fastdb C #, if the field type is defined as CLI. FieldType. cli_asciiz, garbled characters may occur when the Chinese character set is inserted, Tracing code found that during the CopyBufferData process

Mongodb installation and simple useMongodb installation and simple use First install mongodb 1.: http://www.mongodb.org/downloads 2. decompress the package to the directory you want to install, such as d: \ mongodb. 3. Configure the environment

Oracle (1) --> detailed description of database objects (Text explanation, first of all a small understanding ~), Oracle details---- Database object: a set of logical structures ----1. Synonym: alias of an existing object/*Purpose:Simplify SQL