Database Administrator

Xin Xing talks about mysql's data fragmentation and operations under MyISAM engine, Data fragmentation in mysql is closely related to data deletion. When deleting data, it will inevitably lead to discontinuous blank space in the data file. for

When a human is working on a smart phone, a huge data center is dead. On June 23, Paul Brody, vice president of IBM and head of the Global Business Services electronics industry, wrote on the technology website Venture Beat, in the IOT era, the use

Oracle group summary statistics function grouping, oraclegrouping Two days ago, a colleague asked an oracle database to use grouping to complete a statistical report function. This function is pretty cool. The development grouping report can be done

Oracle Database startup failure caused by a vm time backflow, vmoracle Oracle Database startup failure caused by a vm time Backflow This article is an original article. If it is reproduced, please indicate the

Mongodb usage and deployment ppt, mongodb deployment ppt1. mongodb Introduction2. pptHttp://download.csdn.net/detail/u014285882/7807105Error reported when using mongodb database configuration in ThinkPhp framework Before using the D method, you

Mongodb master-slave configuration: replica set, mongodbreplica1. Replica setThe master-slave deployment of mongodb, usually in the replica set mode. Replica set is a group of multiple mongod instances, including one primary and multiple slave

Solve the problem of a large number of unauthenticated users in MySQL, unauthenticated Recently, OJ and related open site operations have been exceptionally slow, causing a crash and no reason has been found! Enter the database server, enter mysql,

Understanding MySql transaction isolation mechanism, locks, and various lock protocols, mysql transactions The understanding of the transaction isolation mechanism of the database is always on the surface, and its content is also forgotten. In the

How to download the installation package by ZOL Downer, packagedowner  How to download the installation package by ZOL Downer Ma Genfeng (Guangdong Unitoll Services ininitialized ated, Guangzhou 510300)   AbstractRecently, Zhongguancun Online

Cross-server data modification and cross-server dataNote: two servers: 192.168.0.22, A192.168.0.3, and database B are backed up on Database A and database B.Write on:Exec sp_addrole server 'itsv2', '', 'sqloledb', 'server address'Exec

Oracle: dump File Import error: only DBA can import files exported by other DBAs, dumpdba Export the dump file of a table from schepaa (DBA permission) and import it to scheab (non-DBA permission). An error is returned. Use the OB tool to set

[Oracle] export and import of OCR backup and recovery, oracleocr Back up and restore OCR using exported import: Before adjusting the cluster, for example, adding or deleting nodes, you should back up OCR once. You can use export to back up to the

About rac crs automatic start and raccrs startAbout CRS auto-Restart ExperimentI. Check ASM[Root @ rac1 ~] #/Etc/init. d/oracleasm statusChecking if ASM is loaded: yesChecking if/dev/oracleasm is mounted: yes[Root @ rac1 ~] #/Etc/init. d/oracleasm

The Ignoring query to other database problem occurs in MySQL, ignoringdatabase When mysql is used today, any input command will output: Ignoring query to other database This error message is very strange. Later, we found that the-u parameter

Oracle exchange partition test, oracleexchange Exchange partition provides a way to migrate data between a table and a table, or between a partition and a partition. Note that it is not in the form of converting a table into a partition or a

PL/SQL learning and plsql LearningDocument 1 -- Created onDeclare-- Local variables hereI integer;BeginI: = 12;-- Test statements hereDBMS_OUTPUT.put_line (I ); End;Document 2 DeclareCursor s isSelect * from city_app.city_server;S _ s %

Solving ora-00054 Oracle lock table problems, ora-00054oracle 1. run SQL: select session_id from v $ locked_object; check the Sessions of the lock table. There may be many sessions, but they are not normal. 2. SELECT sid, serial #, username, osuser

Petelai project experience collection (5) ___ system process design, petela __ There is a process design problem in the design of petelai project, though. NET and Java have workflows, but considering the small size of this project, I simply borrowed

Solve the problem that the Oracle11g empty table cannot be exported. The deferred_segment_creation parameter is added to Oracle11g. The default value is true when the database is created, which means delayed loading. When no data exists in the table,

Sorting and sorting algorithms -- Sorting problems, such as numbers 1, 2, 3, 4, 5, and 6 -- ideas: (1) if 1 is changed to 5, that is, 1 is directly changed to, 2, 3, 4, and 5, respectively, minus 1 and 6 unchanged -- (2) if 5 is changed to 3, 5 is