Database Administrator

Oracle computing continuous login/working days Now there is a report that calculates the number of working days of a user. It is found that the row_number analysis function can perfectly calculate this problem. This SQL statement can solve problems

Install the database Oracle client in Ubuntu 16.04 Install the Oracle database client in Ubuntu 16.04 to connect the Django project to a remote Oracle database. 1. Download the oracle client installation package: Go to

MySQL 5.6 locking users MySQL 5.7 has the same account lock function as Oracle, but MySQL 5.6 does not seem to have it, but it can be used in the following way to set password expiration. The mysql. usertable now has a password_expiredcolumn. Its

New Features of Oracle 12C-Extended Data Types New Feature of Oracle 12C-extended data types. In 12c, compared with earlier versions, data types such as VARCHAR2, NAVARCHAR2, and RAW are extended from 4 K and 2 K bytes to 32 K bytes. As long as

Principle and Practice of MySQL master-slave Replication MySQL master-slave ReplicationMySQL master-slave replication copies the SQL command set originally created and modified databases to the slave database, and re-executes these SQL commands

Install and start MySQL in LinuxI. Comparison of various MySQL installation methods In Linux, MySQL has three major installation methods: RPM installation, binary installation, and source code installation. The advantages and disadvantages of the

Use mysqldump to export a database (table) Mysqldump is used to back up databases or migrate data between different databases. The backup content of mydqldump includes SQL statements used to create and load tables.I. How to Use mysqldump (1) Back up

Two solutions to ORA-30078 errors Recently encountered a ORA-30078 error while trying to create a partition table, prompting "ORA-30078: partition limit must be TIME/timestamp with time zone text", why is it difficult. First, I create a test table

Install MySQL on Ubuntu Server 16.04 and set Remote Access I. Install MySQL on Ubuntu Server 16.04 1. Use the root account Sudo apt-get install mysql-serverApt-get isntall mysql-clientApt-get install libmysqlclient-dev If there is a problem in the

Three methods of MySQL backup The main function of MySQL backup is to quickly, efficiently and securely solve problems in the case of hardware faults, software faults, natural disasters, hacker attacks, and human error, so as to avoid unnecessary

A small example of how PL/SQL implements the split () method in Java As we all know, Java provides the split () String segmentation method for the String class, so it is easy to split the String into a String array using the specified symbol.

MySQL semi-synchronous replication implementationI. Why do I need semi-synchronous replication? MySQL replication is asynchronous by default. After the Mysql Master Server transfers its Binary Log through the replication thread, the Mysql Master

Redis cluster deployment document under Ubuntu 15.10 Linux: Ubuntu15.10. (To make the cluster work normally, at least three master nodes are required. here we need to create six redis nodes, three of which are master nodes and three are slave nodes,

Recovery of RMAN data from different machines is incomplete Source database: Red Hat Enterprise Linux Server release 5.5 (Tikanga) 64bit + Oracle V11.2.0.4.0 + DG + RAC Target Database: Red Hat Enterprise Linux Server release 5.8 (Catthage) 64bit +

Preparations before Datapump data migration In fact, for Datapump migration, if you have participated in XTTS, OGG, Veritas SF, External table increments, and other migration methods, you will find that Datapump is simple and clear. one advantage is

Install Hbase database in Ubuntu Server 14.04 I. Environment preparation 1. Ubuntu14.04-server 2. ssh 3. jdk1.6 4、hbase-0.98.19-Hadoop2-bin.tar.gz (http://www.apache.org/dyn/closer.cgi/hbase) Ii. Installation Steps 1. Decompress hbase

Compile and install MySQL 5.6.16 in CentOS 6.5 Check: uninstall the original MySQL Because MySQL databases are too popular on Linux, the mainstream Linux system versions currently downloaded are basically integrated with MySQL databases, run the

Measure the test taker's knowledge about Oracle Database Bad blocks. How to check Bad blocks of Oracle databases: 1. Use the DBV (DB File Verify) tool; 2. Use the RMAN (Recovery Manager) tool; DBV (DB File Verify) tool: External commands, physical

MySQL 5.6 quickly locates unreasonable Indexes # If CARDINALITY/TABLE_ROWS is less than 10% (experience value), it indicates a high data repetition rate. Generally, you need to consider whether it is necessary to create this index.###################

Spring integrated MyBatis full instance (SHARE), springmybatis To sort out the content in Spring integration MyBatis (Maven + MySQL) 1 and Spring integration MyBatis (Maven + MySQL) 2, prepare a complete example to complete a simple library