Database Administrator

MySQL primary key constraints and uniqueness constraints MySQL primary key constraints and uniqueness constraints are both indexes. The differences between them are: The primary key field can be unique, but the primary key field cannot be NULL.

MySQL tuning and use must-read MySQL should be the most popular WEB backend database. WEB development languages have developed rapidly recently. PHP, Ruby, Python, and Java have their own characteristics. Although NOSQL has been mentioned more

Redis Command Execution Process This problem is simple and simple. The client sends a command request, the server reads the command request, and then the command executor searches for the command implementation, executes the Preparatory operation,

Error handling during Oracle database installation [INS-35172] The following error is reported when Oracle is installed on the desktop when SGA is assigned:[INS-35172] Target database memory (XXMB) exceeds the systems available shared memory ({0}

Undo tablespace usage The undo tablespace is a very important tablespace in Oracle databases, and its usage is also the focus of DBAs. However, in busy production systems, it is easy to see that the undo tablespace usage is very high, or even 100%.

Unix/Linux Kernel Parameters closely related to Oracle The following are several Unix/Linux Kernel Parameters closely related to Oracle. During database installation, the parameters must be adjusted according to the actual situation. Init.

String is split into multiple rows of data (oracle function), multiple rows of oracle Address-http://blog.csdn.net/qq525099302/article/details/47146537 -- Create a split type (used in the function) create or replace type strsplit_type as table of

Java playframework and playframework Shortly after learning java, let's try the architecture and choose a simple architecture. The running environment here is JDK1.7. I tried jdk1.8 but it won't work. The problem is that play-1.2.7 is used for

Consistent hash and hash Consistent hash is a special hash algorithm. After the consistent hash algorithm is used, the number of slots (size) in the hash table only needs to be re-mapped to K/n keywords on average, where K is the number of keywords,

Beckham _ mysql partition instance and Beckham _ mysql instanceMysql partition ExperimentBrief: 1. Create partitions Based on the partition type 2. Manage partitions 3. Examples of partitions and unpartitioned tables   1. Create a partition. Use

NUTCH2.3 hadoop2.7.1 hbase1.0.1.1 solr5.2.1 deployment (3), hadoop2.7 InstallationZookeeper Precondition: Hadoop 2.7.1Hbase 0.98.13Solr 5.2.1/Apache Solr 4.8.1Http://archive.apache.org/dist/lucene/solr/4.8.1/Gora 0.6.1 Gora compilation and Nutch

SUSE Linux source code compilation and installation MySQL 5.6, susemysql This article mainly introduces how to install MySQL 5.6 in SUSE Linux Source Code compiling mode. This article uses SUSE Linux Enterprise Server 10 SP3 (x86_64) system. For

Install mysql in ubuntu 1204 and ubuntu Check whether mysql is installed on the local machine sudo netstat -tap | grep mysql After executing the preceding command, the mysq socket is in the listening status, indicating that the installation is

High-concurrency and high-traffic website architecture: simple ideas and concurrent traffic Architecture*******************************Front end*******************************1. Increase the necessary hardware and bandwidth, and reserve an

Left join, right join, and mysqljoin in mysql Left (outer) join: The left table is dominated by all rows in the left table. The right table lists the data that meets the requirements of the record. Right (outer) join: The right table is the

Beckham _ mysql partition theory learning, Beckham _ mysql theory learningMysql PartitionBrief:I. Why mysql partition II? mysql partition type III. mysql partition technology comparison   I. Why mysql partitioning? 1. When business data increases,

Mysql installation illustration 1. Several common methods for mysqldump: (1) Export the entire database (including data in the database) Mysqldump-u username-p dbname> dbname. SQL (2) Export the database structure (excluding data) Mysqldump-u

Hibernate establishes one-to-one association, and hibernate multiple-to-one Association The following content is organized from the second edition of Hibernate Ing code: The element establishes a customer ing between the customer attribute and

Regularly back up mysql Databases and linuxmysql databases on linuxRegular Database Backup/Usr/sbin/backupmysqlTimestamp = 'date + "% Y-% m-% d-% H-% M-% S "'Mysqldump-uroot-p '123456 databasename>/db $ timestamp. SQLChmod + x backupmysqlInstall

Centos 6.5 final installation xtrabackup 2.2.11 note, centosxtrabackup(1) download xtrabackupwget https://www.percona.com/downloads/XtraBackup/Percona-XtraBackup-2.2.11/binary/redhat/6/x86_64/percona-xtrabackup-2.2.11-1.el6.x86_64.rpm(2) rpm