如何开启/关闭oracle的归档
如果是OPS/RAC环境,需要先把parallel_server = true注释掉,然后执行如下步骤,最后用这个参数重新启动
1、开启归档
a. 关闭shutdown immediate
b. startup mount
c. alter database archivelog
d. alter database opne
2、禁止归档
a. 关闭数据库shutdown immediate
b. startup mount
c. alter database noarchivelog
d. alter database open
归档信息可以通过如下语句查看
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination E:oracleora92databasearchive
Oldest online log sequence 131
Next log sequence to archive 133
Current log sequence 133

TodropaviewinMySQL,use"DROPVIEWIFEXISTSview_name;"andtomodifyaview,use"CREATEORREPLACEVIEWview_nameASSELECT...".Whendroppingaview,considerdependenciesanduse"SHOWCREATEVIEWview_name;"tounderstanditsstructure.Whenmodifying

MySQLViewscaneffectivelyutilizedesignpatternslikeAdapter,Decorator,Factory,andObserver.1)AdapterPatternadaptsdatafromdifferenttablesintoaunifiedview.2)DecoratorPatternenhancesdatawithcalculatedfields.3)FactoryPatterncreatesviewsthatproducedifferentda

ViewsinMySQLarebeneficialforsimplifyingcomplexqueries,enhancingsecurity,ensuringdataconsistency,andoptimizingperformance.1)Theysimplifycomplexqueriesbyencapsulatingthemintoreusableviews.2)Viewsenhancesecuritybycontrollingdataaccess.3)Theyensuredataco

TocreateasimpleviewinMySQL,usetheCREATEVIEWstatement.1)DefinetheviewwithCREATEVIEWview_nameAS.2)SpecifytheSELECTstatementtoretrievedesireddata.3)Usetheviewlikeatableforqueries.Viewssimplifydataaccessandenhancesecurity,butconsiderperformance,updatabil

TocreateusersinMySQL,usetheCREATEUSERstatement.1)Foralocaluser:CREATEUSER'localuser'@'localhost'IDENTIFIEDBY'securepassword';2)Foraremoteuser:CREATEUSER'remoteuser'@'%'IDENTIFIEDBY'strongpassword';3)Forauserwithaspecifichost:CREATEUSER'specificuser'@

MySQLviewshavelimitations:1)Theydon'tsupportallSQLoperations,restrictingdatamanipulationthroughviewswithjoinsorsubqueries.2)Theycanimpactperformance,especiallywithcomplexqueriesorlargedatasets.3)Viewsdon'tstoredata,potentiallyleadingtooutdatedinforma

ProperusermanagementinMySQLiscrucialforenhancingsecurityandensuringefficientdatabaseoperation.1)UseCREATEUSERtoaddusers,specifyingconnectionsourcewith@'localhost'or@'%'.2)GrantspecificprivilegeswithGRANT,usingleastprivilegeprincipletominimizerisks.3)

MySQLdoesn'timposeahardlimitontriggers,butpracticalfactorsdeterminetheireffectiveuse:1)Serverconfigurationimpactstriggermanagement;2)Complextriggersincreasesystemload;3)Largertablesslowtriggerperformance;4)Highconcurrencycancausetriggercontention;5)M


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Zend Studio 13.0.1
Powerful PHP integrated development environment

WebStorm Mac version
Useful JavaScript development tools

SublimeText3 English version
Recommended: Win version, supports code prompts!

SublimeText3 Chinese version
Chinese version, very easy to use

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool
