Oracle

I. Naming rules for table and column names1), must start with a letter2), length cannot exceed 30 characters3), cannot use Oracle's reserved words4), can only use the following characters a-z,a-z,0-9,$, #等Ii. Types of data1), character classChar has

Oracle Database Configuration Monitoring1. Preparation environment: (1) Remote Oracle Service instance or Local service instanceRemote server or Local service side (storage database)(2) Oracle Client (ORACLE–ORACLIENT11G)(3) Pl/sqldeveloper tools2.

1. Introduction to statistical informationThe statistic information mainly is a kind of information which describes the table in the database, the index size, the scale, the data distribution condition and so on. For example, the number of rows in a

1: The company database began to use the MySQL, because the company is doing a confidential project, so in the project log too much when the project has an explosion of the signs AH (30 billion data, seemingly MySQL a little support). Then the team

Default User of Oracle: System,sys,scott; 1: View login username: Show user;2: View data dictionary: dba_users;3: Table Space Overview: Logical storage space for the database;　　Data dictionary is a database provided by the table, the user to

The principle of selecting a primary key: Minimum sex Choose to use a single key as the primary key Stability Try selecting a column with fewer values to update as the primary key 1. Creating a data table (CREATE

First, the principle of efficient SQL statement In where = relational operation Avoid using functions in relational operations, unless you use a function to make an index Try not to implicitly convert data types, data types must

Reference material "Oracle in Layman's"Interest + diligence + Persistence + method ≈ SuccessFour rules of DBA survival1. The backup is heavier than everything else;2. Think twice;3.RM is dangerous;4. You have to make the specification;Chapter One:

First, the basic operationNothing to do, organize the Oracle database related operations, later standby .....PS:SATP for user satp_data as table space1 1. Delete Table Space2 DROPTablespace Satp_data including CONTENTS anddatafiles;3 4 2. Deleting

--Declaring a function--replace Replace put back--sal: Monthly SalaryCreate or Replace function Fn_get_avg_sal (DNO number)Return number is avgsal emp.sal%type; --Returns and numbers called Avgsal are the types of Sal fields in the EMP employee

The way to use bulk binding (bulk binding). When looping through SQL statements that execute a bound variable, a large number of context switches occur in PL/SQL and in the engines (switches). With bulk binding, data can be batched from the Plsql

The child node is traced to the root node.SELECT * from persons.dept start with deptid=76 connect by prior Paredeptid=deptidTraverse the child nodes (without the root node) through the root node.SELECT * from persons.dept start with Paredeptid=0

Modify Host Name:Under the root user,Hostname node1.test.comVi/etc/sysconfig/networkVi/etc/hostsVI ~oracle/.bash_profile$ NETCA Monitoring$ LSNRCTL Status Listening state$ NETSTAT-TLNP | grep 152115$ dbcaGeneral or transactional processing:SYS

It is best not to do other unrelated actions after deleting data① determining when to delete data② This statement to find the deleted data: SELECT * from table name as of timestamp to_timestamp (' delete point ', ' yyyy-mm-dd hh24:mi:ss ')③ deleted

Grammar:SELECT ... From + table name START With + condition 1CONNECT  by PRIOR + conditions 2WHERE + condition 3DescriptionThis method is used to query the data of the tree structure. For example, we have a structure like thisThen build a table

Basic use of SELECT statementsYou can query the required columns, rows, multi-link tables, connection queries.Select E.*, e.sal/ from P_emp EThe select is followed by the result to be displayed, which can be a pseudo-column derived from an operation

Use of Oracle KeywordsUse Insert to add data: INSERT into table name VALUES (add corresponding number); COMMIT;INSERT into P_empVALUES (' TOM2 ', ' clerk ', 7902, Sysdate,, NULL, 30);COMMIT;Try delete Delete a data: Delete table name WHERE condition;

A project requires a view to build a primary key, here is a sampleCREATE or replace VIEW sme_v_a .... (Agentid,agentname,busynum,restnum,resttime,devicenonum,devicenosum,CONSTRAINT agentstatic_pk PRIMARY KEY (agentid) RELY DISABLE

The deadlock is due to the fact that two objects request another resource with one resource,Another resource happens to be holding the two objects, causing the two objects to be unable to complete the operation, and the resources held cannot be

1. CREATE TABLE Space Data_basic(1) Orale User Login System(2) Sqlplus/as sysdba; DBA User Login database;Execution: Create tablespace tab_sts_basic datafile '/oracle/app/uboss/oradata/uboss/datafile/uboss_def01.dbf' Size 512M; --The path should be