Oracle

My Oracle database was installed last November and then configured, and then it was normal, no problem, but then I didn't use my local Oracle, and PL/SQL was always a colleague's machine, Then today suddenly want to do some tests on their own

When creating a table, add a NOT NULL constraint to the column in the following form:column_name Data_type[constraint constraint_name] NOT NULLWhere constraint constraint_name represents the specified name for the constraint.You can also add a NOT

Password file function:The password file is used for the DBA user's login authentication.DBA User: A user with sysdba and Sysoper permissions, that is, the SYS and system users of Oracle.Log on Locally:1) Operating system certification:[Email

--Select 30 of employees in the departmentSELECT * from EMP where deptno=30;--List all clerks ' names, departments, numbers--Using the internal connection, that is, the equivalent link, is also the most commonly used linksSELECT ename,empno,dname

1 Problem descriptionPreviously wrote a blog to delete the Oracle home directory, refer to:Linux platform mistakenly delete home Oracle root directory solutionhttp://blog.csdn.net/tianlesoftware/article/details/43794273This is the depth of this side,

1. On the occasion of the New Year in 2015, this is the happy time of the family, the vast number of silent fighting in the first Oracle maintenance engineers to express their admiration, there is a vast number of Oracle maintenance personnel to the

1. Tablespace Fragmentation *********************** ----1. View FSFI values Select A.tablespace_name,trunc (sqrt (max ( Blocks)/sum (blocks)) * (100/sqrt (sqrt (count (blocks))), 2) Fsfi from Dba_free_space a,dba_tablespaces bwhere A.tablespace_name=

MapManagementAction TriggerMap triggers the supplemental standardOracle Coherencethe ability to provide a highly customizable cache management system. For example, map triggers can prevent illegal transactions, perform complex security

There is a requirement on the recent project to describe a sequential card number using a segment, such as: 1,2,3,4,5,8,10,13,14,15,16 to be displayed as: 1-5,8,10,13-16 formBut the original Wm_contact function is separated by commas, and does not

Chen Kozhan-Welcome reprint, Reproduced Please indicate, thank you!=====================Newly installed oracle11g R2 data, this want to use Sql*plus test test, did not expect to appear the above picture problem:Cause: There is no configuration

The scope of the PL/SQL variable, which is valid within the current block.DeclareV_num number (5,2): = 1.23;BeginDeclare V_num char (10);BeginV_num: = 12345;Dbms_output.put_line (V_num);EndDbms_output.put_line (V_num);EndSql> Declare2 v_num Number (5

There is a correlation experiment for null values today. A discussion of NULL value insertions. 1, you can perform an insert ' or null operation in PL/SQL, provided the column is allowed to be empty. 2, you can perform a series of database

in the The dbms_random package in Oracle encapsulates a number of functions that generate random numbers and random strings, which are commonly used in the following two:Dbms_random. VALUE function This function is used to produce a random number

The common use is to remove the space, how many people do not know that they can actually do to remove the space, it has LTrim (), LTrim (x, Y) method------- go to both spaces, go left space, go right space --------Select trim (' x-rapido

Today at noon will be nearly a few points when suddenly received SMS warning prompt, the company's software for a long time without a single production. The first reaction was that the company's software was hung up, so it was immediately viewed.

Oracle Official Documentation Tips:If you had specifiedDELETE INPUTRather than DELETE all INPUT, thenRMAN would has only deleted the specific archived redo log files, it backed up. For example, RMAN would delete the logs in/arc_dest1 if these files

Oracle AWR report analysis and OracleAWR Report Analysis * Definition: awr report is a performance collection and analysis tool provided by oracle at 10 Gb. It provides a report on the usage of system resources over a period of time. Through this

How to connect a server from Sybase to Oracle The interconnection of different database platforms is generally called the heterogeneous service of databases. Currently, all major databases can achieve such Heterogeneous Interconnection, but the

[ORACLE] redo and undo _ change VectorsRedo and undo1.1 oracle 9i task execution process -- DML data update operation: 1. Create a Change vector (Save the data before the change) to describe the change of the undo data block; 2. Create a Change

Triggers, oracle triggersDirectory I. DML triggers Ii. INSTEAD_OF trigger Iii. system triggers 4. Delete trigger modify trigger status close open -- Description -- 1. BEFORE the event (BEFORE) AFTER the event (AFTER) -- 2. trigger Condition Clause