Database Administrator

Solutions to frequent sleep processes in MySQL The company has a Linux server dedicated to running the company's WEB services. due to historical reasons, there are a large number of sites and pages, which often lead to a large number of sleep

Notes on installing MySQL-Cluster 7.3.4 on CentOS 6.5 Install MySQL-Cluster 7.3.4 Process notes on CentOS6.5 (two days to search for various materials and test results ). In order to install the Cluster, the study took 2 days to complete, so the

Invalid and unavailable objects for Oracle Database Reconstruction Invalid and unavailable objects Invalid PL/SQL objects and unavailable indexes may affect performance. Invalid PL/SQL objects must be recompiled before they can be used. This

MySQL table lock wait Today, an online business problem occurs because a table with a simulated auto-incrementing sequence is locked and services related to the table are affected. Online Information: 1. This table has only one id field. 2. The

ORA-16753 error troubleshooting 1. Use dgmgrl to set the database to read-only mode: DGMGRL> edit database dg_name set state = read-only; ORA-16753 Resource guard cocould not open standby database Cause: Resource guard cocould not open standby

When sqlplus is started, it searches for and loads two files: login. SQL and glogin. SQL. Environment Settings after sqlplus is startedSqlplus searches for and loads two files: login. SQL and glogin. SQL.The glogin. SQL file is stored in the $

One Oracle instance is bound to multiple services Background: In the early stage of the project, two instances were created on one server, and two connections were configured on the client. Now, you need to integrate the two instances into one of

Why Does Oracle Rac opatch auto fail to hit Rac database home?First explain the environment: OS: AIX 7.1Oracle version: Oracle Rac 11.2.0.3 before the release of the 11.2.0.3.9 Patch Set, Rac is not officially used, so simply hit the latest 11.2.0.3.

Expdp ora-31640, ora-19505Oracle @ db01:/oraapp/oracle/backup> impdp \ '/as sysdba \' directory = DB_BACKUP dumpfile = newdb.20140918.dmp logfile = newdb_0919.log parallel = 4 c>Import: Release 11.2.0.3.0-Production on Fri Sep 19 11:27:12

Tracing datapump sessions, tracingdatapump Tracing datapump is not straight forward, you can trace the datapump worker (dw00) or datapump master (DM00) with 10046 to get the SQL etc or use the TRACE option in expdp/impdp Where in expdp has an option

Use Mybatis to pass multiple parameters (three solutions) and mybatis Solution There are three methods to transmit multiple parameters that I have come into contact. Solution 1 DAO layer Function Method Public User selectUser(String name,String

Mysql uses indexes to optimize order sorting, and mysqlorder Original address: http://www.phpthinking.com/archives/433 In the database, we usually perform index operations on some fields, which can improve the data query speed and improve the

SQL date completion and SQL completion IF OBJECT_ID ('tbl') IS NOT nullddrop TABLE TBLGOCREATE TABLE TBL (DATE) goinsert tblselect '2017-09-30 'union allselect '2017-10-06' goDECLARE @ date dateselect @ DATE = MAX (DATE) from tbl; with tas (SELECT

How does Hibernate manipulate Clob data? hibernateclob In POJO, a large String object can be declared as a java. lang. String or java. SQL. Clob type. When a program loads Clob data from a database, it only loads a logical pointer of Clob data. You

[Mongo] group by time (formatted by time), mongo GroupThe Group key can use the original field or a function to format the date. /* 0 */{ "_id" : ObjectId("541fcc51c6c36038bc6b81cd"), "url" : "http://wifi21.com/", "addtime" :

[Mongo] couldn't connect to server 127.0.0.1: 27017 at src/mongo/shell/mongo. js: L112, 201727017 Today, when mongo was started, an error occurred. My environment is Windows 7. E:\server>mongoMongoDB shell version: 2.4.5-pre-connecting to: testMon

[MySQL] MySQL database transactions in the production environment are always RUNNING, and mysqlrunning Preface: The operations staff reported that a ticket was submitted and the page was not returned. 1. At first, I suspected that the application

[Database] query optimization summary and database query SummaryI. Rational Use of Indexes Usage principles: 1. columns that are frequently used as conditions in queries should be indexed. 2. columns that are frequently sorted, grouped by, or order

Powerdesigner converts PDM to MYSQl databases, powerdesignerpdm Use PowerDesigner to design and build a MySQL database1. Create a database creation script using PowerDesigner1. Design CDM (Conceptual Data Model)2. Select Tools> Generate Physical

Common Methods for viewing Oracle execution plans-Series 2: oracle execution plans Continued article: http://blog.csdn.net/bisal/article/details/38919181 3. AUTOTRACE Switch Turn on AUTOTRACE in SQLPLUS to get the SQL Execution Plan. The prompt