Database Administrator

[Oracle] Partition Table: range partition, list partition, hash partition, rangehash ************************************** *********************************** *** Original article: blog.csdn.net/clark_xu Xu changliang's column**********************

[Oracle] Character Set, National Character Set, and NLS_LANG Runtime Library, using lenls_lang**************************************** ********************************* *** Original article: blog.csdn.net/clark_xu Xu changliang's column**************

Differences between primary key and Index 1.The primary key must be a unique index, and the unique index is not necessarily a primary key.A primary key uniquely identifies a row in a table. A table can have only one primary key, but multiple

JAVA transaction attribute ACID; java transaction attribute acidATOMICITY ):A transaction must be completely completed or canceled without ambiguity. When an error occurs in any operation, the effect of all operations that constitute the transaction

Libmysqlclient. so.18: cannot open shared object file: No such file or directory, export dobject error: [root@localhost ~]# /usr/local/nagios/libexec/check_mysql -h/usr/local/nagios/libexec/check_mysql: error while loading shared libraries:

Connection Pool technology and technology Concept The connection pool is a buffer pool technology for creating and managing a connection. After the connection pool is ready, it will be used by any thread that needs them. The technology that

[Data Center Charging System] use of triggers and data center charging system triggers In data center reconstruction, many functions involve operations on multiple tables in the database. For example, after the checkout is successful, the following

View the SQL Execution history of the Oracle database. Method 1: Use the LogMiner Tool Advantage: the log content can be fully mined to find all SQL statements that have been executed Disadvantages: Method 2: view the HIST View Advantage: simple,

High concurrency: Memcached practice lesson 10th-part of the code for "Memcached Get data" Section 2: memcached practiceHigh concurrency: Memcached practice lesson 1-"Memcached Get data" part of Code 2 I. Logic of reading and writing the Memcached

Processing Method and report processing method of adding datasets to the rundry report Added the dataset function in the rundry report. Multiple datasets can be associated in a cell (main cell). After Association, multiple datasets are used as one

Cannot delete or update a parent row: a foreign key constraint fails solution, constraintfails When I use the delete from table statement to clear data in a table, the following error occurs: Cannot delete or update a parent row: a foreign key

Ora 12514 tns listeners cannot be recognized currently, 12514tnsFind a text file: E: \ oracle \ NETWORK \ ADMIN \ listener. ora also has a tnsnames. ora file in the same path (this is my own installation path) Open listener. ora: # Listener.

MySQL Study Notes (1), mysql Study NotesPreface Note content is based on the database course of the lab building. If you are interested, you can click it to learn it. It should be a note, so the content may be simple and incomplete. Because note

Mysql 1366 error: incorrect data insertion due to Character Set conflict. Solution: mysql1366 I. error message: errorCode: 1366 Caused by: java. SQL. SQLException: Incorrect string value: '\ xE7 \ xAE...' for column 'description' at row 1 Ii. Cause

SQL and SQL tutorialsAn inner join is a join in which the values in the columns being joined are compared using a comparison operator. In the ISO standard, inner joins can be specified in either the FROM or WHERE clause. this is the only type of

[Minute-second function for getting system time in Oracle], oracle minute-second function 1. Get the year of the current system time Select to_char (sysdate, 'yyyy') from dual; -- year 2. Obtain the month of the current system time.Select to_char

An error occurred while converting from nvarchar to numeric. nvarcharnumeric When writing an SQL statement, you need to compare the nvarchar column of the (dictionary) table with the numeric column of Table B; The dictionary data stored in the

SQL and SQL tutorialsInner joins return rows only when there is at least one row from both tables that matches the join condition. inner joins eliminate the rows that do not match with a row from the other table. outer joins, however, return all

Use of the screen command in Linux Note that the screen command is not installed in rhel6 by default: [root@rhel63single yum.repos.d]# yum install screenLoaded plugins: product-id, refresh-packagekit, security, subscription-managerUpdating

Poor memory: 92-spring3 Learning (13)-small differences between spring and hibernate database access, 92-spring3-spring In the Spring data source, autoCommint is set to true by default. That is to say, by default, the statements executed through