Arithmetic Operators +,-,×,÷ Comparison Operators ＝,<>,!=,>,<,>=,<= BETWEEN,IN,IS NULL Logical Operators AND,OR,NOT[LIKE | IN | BETWEEN | NULL] String Operators LIKE,|| Operators precendence parentheses > comparison > AND > OR (…

Introduction to text manipulation on UNIX-based systems https://www.ibm.com/developerworks/aix/library/au-unixtext/index.html     A basic tenets of UNIX philosophy is to create programs (or processes) that do one thing, and do that one thing well. It…

commands : show sys connect sys as sysdba or connect system as sysdba logout or disc clear screen or cle screen (utlsample.sql  —> unlock scott tables.sql  —> all tables data.sql  —> add data into tables) connect scott/tiger start C:\utlsample.sq…

Hive Data Definition Language Hive Data Definition Language Overview Create/Drop/Alter Database Create/Drop/Truncate Table Alter Table/Partition/Column Create/Drop/Alter View Create/Drop/Alter Index Create/Drop Function Create/Drop/Grant/Revoke Roles…

Database API Introduction Basic Usage Selects Joins Aggregates Raw Expressions Inserts Updates Deletes Unions Introduction An improved Database API was recently added, which includes a QueryBuilder and a simple but powerful Model. Everything regardin…

20元现金领取地址:http://jdb.jiudingcapital.com/phone.html内部邀请码:C8E245J (不写邀请码,没有现金送) 国内私募机构九鼎控股打造,九鼎投资是在全国股份转让系统挂牌的公众公司,股票代码为430719,为“中国PE第一股”,市值超1000亿元. src:http://www.blackmoreops.com/2015/07/15/download-hacking-team-database/?utm_source=tuicool Recently…

本文转自:https://blogs.oracle.com/askmaclean/entry/oracle_database_12c%E6%96%B0%E7%89%B9%E6%80%A7_32k_varchar2 在Oracle Database 12c中,我们可以为varchar2.nvarchar2和RAW数据类型指定32767 bytes 的最大长度了, 以便用户将更长的字符串存储在数据库中. 在12c之前的版本中,varchar2和nvarchar2数据类型的最大长度是4000 byte…

Basic of MySQL 创建数据库: mysql> create database xxj; Query OK, row affected (0.00 sec) 列举数据库: mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | xxj | +--------------------+ 进入某个数据库: mys…

        http://www.postgresql.org/docs/9.1/static/functions-datetime.html   Search Documentation:  Home → Documentation → Manuals → PostgreSQL 9.1 This page in other versions: 9.0 / 9.1 / 9.2 / 9.3 / 9.4  |  Development versions: devel  |  Unsupporte…

简介 在数据库的迁移和升级场景中,我们经常会遇到一个问题:在做压力测试时,如何模拟真实的业务压力,解决这个问题的方法有很多,比如:应用方开发模拟程序或者使用压力测试工具模拟,如load runner,但是,如果要说哪种方法能最大限度地模拟真实业务压力,我认为还是Oracle的Database Replay(数据库重放)功能,Database Replay功能是Real Application Testing的一部分,它的基本原理图如下: 简单说,Database Replay可以在生产数据库上“…