Oracle

Error when using Emctl start Dbconsole:environment variable oracle_unqname not defined. Please set Oracle_unqname to database unique nameWorkaround:Set environment variables: Export oracle_unqname= $ORACLE _sidIf not, remove the EM

Field CommentSELECT * from User_col_comments;Table notesSELECT * from User_tab_comments;Query field typeSelect Column_name,data_type,data_length from User_tab_columns where table_name= ' TableName ' and column_name in (' age_id ', ' month_id

[Email protected] ~]# su-oracle[Email protected] ~]$ sqlplus "/as sysdba"Sql*plus:release 11.2.0.4.0 Production on Fri Apr 17 17:45:31 2015Copyright (c) 1982, Oracle. All rights reserved.Connected to:Oracle Database 11g Enterprise Edition Release 11.

Experiment with the EMP table from the Scott user first.EMP table has a field, one is Empno (employee number), the other is MGR (higher manager number)Here is all the data in the table 1 select* from emp start with  empno=7698

Suppose there is a student table student, the student table has a name, a score, a course number, and now I need to sort the students ' grades according to the course.SELECT * FROM Student1. Rank over () can be achieved on the student rankings,

(1) The concept of table space and partitioned tableTable Space:is a collection of one or more data files, all of which are stored in the specified table space, but are primarily tables, so called table spaces.Partition table:When the amount of data

Oracle's processing of compressed data is based on database blocks, essentially by eliminating duplicate data in the database to achieve space savings.Specific practices:Compares all the fields or records contained in a block, where repeated data is

The data used for the test is the EMP table in Scott/tiger mode:We use the job and sal two column tests:The above statement refers to the job placement group (partition by job) and then ranks within each group by salary (SAL). Notice the

There are a variety of problems in the use of Long types, and it is not recommended& && Use (for command mode only)& for specifying variable,&& for outputting existing variablesDescritpion Display object information (for command mode only)For

sql>set colsep '; -Field output delimiterSql>set echo off; Displays each SQL command in the script started by the start, which defaults to onsql> set echo on//Set Run command is whether to display statementssql> set feedback on; Set display "xx row

#!/bin/shCat /etc/sysconfig/networkNetworking=yesNetworking_ipv6=noHostname=dbEofHostname DBCat /etc/hosts127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4:: 1 localhost localhost.localdomain localhost6

oracle10g after installation, there are usually the following services:1.OracleCSServiceThe Oraclecsservice service manages the configuration of the cluster by controlling the members of the cluster nodes and notifying them when the node is joined

ORA-02049: Timeout: Distributed Transaction Processing wait lock Simulation I want to simulate this error and see what the problem is. Create a table on Database B: create table TEST(A NUMBER,B DATE);insert into test (A, B) values (2, to_date('16-04-

Oracle practical tips 1. Flashback Note: delete the "T_SPC_ROOM" table, but you can use the following command to restore the table without commit.   flashback table MW_APP.T_SPC_ROOM to before drop2. Handling special characters   NOTE: If special

PL/SQL webpage access (get or post), plsql When we develop a plsql program, it is inevitable that we sometimes access data from some external websites. At this time, we need to use the utl_http package.   Before using the utl_http package, check

How to select database management system products Database Management System (DBMS) is the core part of enterprise operation and analysis systems. Data is like blood for enterprises, while database management systems are hubs for smooth data flow.

Oracle number type Scale is 0, oraclescale Today I encountered a very interesting problem caused by NUMBER Scale. I will use a simple test case to demonstrate this case. Suppose there is a TEST table with a field type of NUMBER, And I insert the

Oracle converts score rows into columns 1. The table contains the following data: Name Subject January February March Zhang San Chinese 30 40 50 Zhang San Mathematics 56 65 78

A small example of grouping and summation in oracle Cold weather in April 9, 2015Table gw_log is designed as follows: Name Type Nullable Default Comments ------------ ----------- -------- ------- ---------- ID VARCHAR2 (50) Message id SERVICE_ID

Oracle expdp and impdp commands-- Create a remote data connectionCreate database link DB_MZDB11 connect to YTMZTWO identified by YTMZTWO909 using 'mzdb11 ';-- Create a local directoryCreate directory db_mz as 'C :';-- Authorize the user to read and