如果你不小心覆盖了之前的存储过程,那得赶紧闪回,时长越长闪回的可能性越小,下面为大家介绍下恢复原理 如果你不小心覆盖了之前的存储过程,那得赶紧闪回,时长越长闪回的可能性越
如果你不小心覆盖了之前的存储过程,那得赶紧闪回,时长越长闪回的可能性越小,下面为大家介绍下恢复原理
如果你不小心覆盖了之前的存储过程,那得赶紧闪回,时长越长闪回的可能性越小。原理很简单,存储过程的定义就是数据字典,,修改数据字典跟修改普通表的数据没有区别,此时会把修改前的内容放到undo中,我们可以根据这一点来进行闪回,所以我说要尽快,要不然找不回来了。下面我们来做一个实验:
1.在用户TEST下14:31下建立存储过程
代码如下:
create or replace procedure GG_TEST
as l_cnt number;
begin
for i in 1 .. 10000
loop
execute immediate 'select count(*) from t where x = ' || i into l_cnt;
end loop;
end;
2.在用户TEST下在14:33下删除存储过程
代码如下:
drop procedure GG_TEST;
3.登录到sys账户下
复制代码 代码如下:
create table p_temp as
select *
from dba_source as of timestamp TO_TIMESTAMP('2014-05-04 14:33:00', 'YYYY-MM-DD HH24:MI:SS')
where TYPE = 'PROCEDURE'
And owner = 'TEST'
And Name = 'GG_TEST';
select text
from p_temp
where name like upper('%GG_TEST%')
and owner = 'TEST'
order by line;
TEXT
---------------------------------------------------------------------------
procedure GG_TEST
as l_cnt number;
begin
for i in 1 .. 10000
loop
execute immediate 'select count(*) from t where x = ' || i into l_cnt;
end loop;
end;

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

Yes,it'ssafetostoreBLOBdatainMySQL,butconsiderthesefactors:1)StorageSpace:BLOBscanconsumesignificantspace,potentiallyincreasingcostsandslowingperformance.2)Performance:LargerrowsizesduetoBLOBsmayslowdownqueries.3)BackupandRecovery:Theseprocessescanbe

Adding MySQL users through the PHP web interface can use MySQLi extensions. The steps are as follows: 1. Connect to the MySQL database and use the MySQLi extension. 2. Create a user, use the CREATEUSER statement, and use the PASSWORD() function to encrypt the password. 3. Prevent SQL injection and use the mysqli_real_escape_string() function to process user input. 4. Assign permissions to new users and use the GRANT statement.

MySQL'sBLOBissuitableforstoringbinarydatawithinarelationaldatabase,whileNoSQLoptionslikeMongoDB,Redis,andCassandraofferflexible,scalablesolutionsforunstructureddata.BLOBissimplerbutcanslowdownperformancewithlargedata;NoSQLprovidesbetterscalabilityand

ToaddauserinMySQL,use:CREATEUSER'username'@'host'IDENTIFIEDBY'password';Here'showtodoitsecurely:1)Choosethehostcarefullytocontrolaccess.2)SetresourcelimitswithoptionslikeMAX_QUERIES_PER_HOUR.3)Usestrong,uniquepasswords.4)EnforceSSL/TLSconnectionswith

ToavoidcommonmistakeswithstringdatatypesinMySQL,understandstringtypenuances,choosetherighttype,andmanageencodingandcollationsettingseffectively.1)UseCHARforfixed-lengthstrings,VARCHARforvariable-length,andTEXT/BLOBforlargerdata.2)Setcorrectcharacters


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

SublimeText3 Linux new version
SublimeText3 Linux latest version

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

Notepad++7.3.1
Easy-to-use and free code editor
