Database Administrator

Use the date type in PL/SQL Use the date type in PL/SQL Previous articles introduced the use of strings and numbers in PL/SQL. There is no doubt that strings and numbers are important, but it can be determined that no application depends on the date.

Oracle synonym + dblink Application Oracle synonym + dblink Application Business Requirements: original database (10.2.0.4.0), new database (11.2.0.3)Due to program requirements, you need to map a user in the new database to the user in the old

PostgreSQL Stream mode construction PostgreSQL Stream mode construction 1. Compile and install Yum install-y gcc-c ++ automake autoconf libjpeg-devel libpng-devel freetype-devel libxml2 libxml2-devel zlib-devel glibc-devel glib2 glib2-devel bzip2

SQL join and sqljoin ================================================================================================ ====1. Theoretical knowledge points SQL join SQL join is used to query data from two or more tables based on the relationship

Forcibly obtain the next value of the sequence/current value (oracle function), oracle Function Http://blog.csdn.net/qq525099302/article/details/47146393-For more information about how to use a function to obtain the sequence value, see here. --

High Table space usage in SYSAUX The SYSAUX tablespace is an auxiliary tablespace of the system tablespace. It mainly stores EM-related content and table statistics, AWR snapshots, and audit information, if SYSAUX tablespace is not configured by

Beckham _ mysql SQL statement optimization process, Beckham _ mysqlsql statementSQL statement OptimizationI. general steps for SQL Optimization (1) Use the show status command to understand the execution frequency of various SQL statements. (2)

Concepts of User and Schema in Oracle, oracleschema In database theory, database users and database models are not necessarily related. For detailed explanations of database models, you can find them

Redis command details, Redis command details1. set setnx setexset associates the value of the string value with the key. If the key already exists, it overwrites the original one. If it does not exist, it is created. Setnx sets the key value as

Mysql Study Notes-mysql database installation and mysql Study Notes 1. Run the mysql installation package and select Custom installation (the installation path should not contain Chinese characters; otherwise, an error will occur during

Common listening errors in ALERT logs 2: troubleshooting of ORA-3136 errors, alertora-3136This problem has recently been encountered in multiple large systems. Generally, it can be ignored if the client does not reflect exceptions.If you encounter

MySQL Study-MySQL-type tools (MySQL Administrator) and mysql-mysqlMySQL Study-Use of MySQL-shaped tools (MySQL Administrator)System Environment:Operating System: Windows 7 (64):

A preliminary understanding of EF, a preliminary understanding of English EF: EntityFrameWork is a framework (the so-called framework can be understood as directly using code already written by others), and this framework is an ORM framework (Object/

[Translated from mos] After clicking the finish button, dbca or dbua hang will stay, After the "finish" button is clicked, either dbca or dbua hangSource:DBCA/dbua appears to hang after clicking finish button (Document ID 727290.1) Applicable:Oracle

MYSQL triggers SQL SERVER instances in real time. The following describes how to update a mysql data table to trigger the addition, deletion, and modification operations on the corresponding table in SQL server. First, add the triggers for the

Some useful SQLite commands are summarized, and sqlite commands are useful. Display table structure:Copy codeThe Code is as follows:Sqlite>. schema [table]Obtain all tables and views:Copy codeThe Code is as follows:Sqlite>. tablesObtain the index

Redis client protocol implementation, redisprotocol On the official website, you can visit http://redis.io/clientsto find some redis clients that have already been proven. For more information, see. In fact, the previous article http://blog.csdn.net/

Oracle password management allows a user to log on up to three times with an oracle Password If a user fails to log on three times in a row, the user is locked for two days. After two days, the user can log on again.Create a profile file: Update

Hive merge (small file merge ), When the Hive input is composed of many small files, if file merging is not involved, a map task is started for each small file.If the file size is too small, so that the start and initialization time of the map task

[SQL] -- triggers, SQL triggersConcept Trigger is a method provided by SQL server to programmers and data analysts to ensure data integrity. It is a special stored procedure related to table events, its execution is not called by a program, nor is