Database Administrator

I started a project a few days ago. I used MySQL, but the project needed an Oracle database. After a month, I changed all the programs to an Oracle database, some differences between MySQL and Oracle are found during the operation. 1. mySQL can

1. installation environmentOperating System: Red Hat Linux Enterprise AS 4.0Database: MySQL 6.0.6Web server: Apache 2.2.9Script Language: PHP 5.2.6 2. Install MySQL 6.0.6 # Groupadd mysql# Useradd-g mysql# Tar xzvf mysql-6.0.6-alpha.tar.gz# Cd mysql-

Alas, the project requires Oracle. I really don't want to use this large database for computers with low memory and CPU clock speed. No way. I may need to use my computer during review. I have to configure the database first. It is very convenient

The format of the INSTR method isINSTR (source string, target string, start position, matching serial number) For example, in INSTR ('upgrade FLOOR ', 'or', 3, 2), the source string is 'upgrade FLOOR', the target string is 'or', And the start

1). MySQL installation layout in Ubuntu: /Usr/bin client program and mysql_install_db/Db database and log files (custom)/Var/run mysqld Server/Etc/mysql configuration file my. cnf/Usr/share/mysql Character Set, baseline program and error message/Etc/

To speed up transaction processing, Oracle adopts the read consistency mechanism. When data is not submitted after a session is updated, other sessions read the results before the update. This greatly improves the efficiency of data concurrency, but

Some want to run database operations at a specified time. If these operations are performed on the WEB Front-end, server resources will be wasted, because the web page needs to be refreshed constantly and then determined to execute the operation...

Oracle-user-managed backup (1) I. first, you must know the table space and file information in the database. There are several performance views: v $ datafile, v $ tablespace, v $ tempfile, v $ logfile, v $ controlfile, dba_tablespaces,

DML operations. All Oracle processes are executed together! The user transmits the DML operation statement to the buffer cache in the sga through the process, and then updates the changed data block in the buffer cache, then, the logwr process first

Last Review: introduced the concept and installation of Neo4j, and introduced two tools: Git and Maven. This article describes the Neo4j Spatial project and space data (vector) storage.1. Introduction to Neo4j Spatial 1.1Neo4j Spatial concept The

Since Mysql5.1, the partition function has emerged. Table Partitioning is like dividing a large table into several small tables. You do not need to perform full table scanning when performing a query, you only need to query the table partitions that

I. in Linux   The Startup Script of app01 application server is as follows:   #! /Bin/sh ---- # Under aix or hpux #! /Bin/ksh If ['whoam '! = 'Weblogic ']; thenEcho 'login User error! 'Exit 9Fi Export srvName = app01Export adminUrl = http: // Manage

I. Weblogic planning: Server Name Port Ip Remarks Xyyadmin 7001 10.10.54.74 Manage servers App01 8001 10.10.54.74 Application server belongs to node Management 2. For weblogic installation,

1. MySql + Memcached architecture Problems MySQL is suitable for storing massive data. Many companies have used this architecture to load hotspot data to the cache through Memcached to accelerate access. However, as the business data volume

Symptom: After the CRS is restarted on both nodes, this instance cannot start with the CRS. After CRS is started, crs_start-all can be used to set up the resources not started, and no error is reported. Analysis: Find the cause in crsd. log and

• Group function:-type and syntax-use AVG, SUM, MIN, MAX, COUNT-use DISTINCT keyword in group function-NULL Value in group Function What is group function? The group function calculates the row set and provides a result for each group. Unlike a

Use the TO_CHAR function to process a date The TO_CHAR (date, 'format _ model') format style has the following features: • must be placed in single quotes • case sensitive • can contain any valid date format element • has a fm element, to delete

Oracle starts archive mode and related parameters, which involve the following parameters: log_archive_min_succeed_dest dynamic parameter log_archive_dest_state _ parameter Log_archive_format log_archive_dest_11. Enable archive Mode SQL> show

1. Table Name and column command rules: It must start with a letter and cannot exceed 30 characters. Oracle reserved words cannot be used. Only A-Za-z0-9 $ # and so on can be used. TABLE: partition table, table partition cluster index table

OMF, full name: Oracle_Managed Files, that is, Oracle file management. Using OMF can simplify the Administrator's management work, without specifying the file name, size, path, name, size, the path is automatically allocated by oracle. When deleting