Database Administrator

I. constraint operations1: Change the constraint name:Alter table TName rename constraint oldname TO newname;2: delete ConstraintsAlter table TName drop constraint cname3: Stop ConstraintsAlter table TName modify constraint cname DISABLE;4:

Password Complexity is an important aspect for IT auditors to check whether a system is secure.IT policies often point out that the password should have a minimum length and contain a mix of uppercase letters, lowercase letters, numbers, and special

Ln-s source dist is used to generate a connection (dist) to the source When modifying mysql, remember: 1: Stop the mysql service first (stop all services first and then modify them) Service mysql stop or stop mysql. server stop under mysql

DBAs do not have to back up files. Eygle is called the DBA's nightmare. So far! Although many people think that backup of parameter files is not important, you often suffer! Parameter file. For windows, spfile and pfile of Oracle are in the E: \

1. Install MySQL under FreeBSD Tar zxf mysql-5.0.41.tar.tar Cd mysql-5.0.41 . /Configure -- prefix =/home/happyiww/mysql-5.1.18-beta -- with-tcp-port = 7788 -- with-unix-socket-path =/tmp/happyiww. mysql. sock -- with_innodb --

The first upgrade is actually a bank production database, which is under heavy pressure and hard to work and has been prepared for a week. on that day, the Bank gave me five hours of time, which is really insufficient. no way, just stick your head

Solve the Problem of freezing mysql-query-browser After I upgrade my system to Ubuntu 8.04, mysql-query-browser will be frozen after I click the database. After searching for a method on the internet, you need to modify a file in the source code.

Pfile is used for Oracle8i and can also be used in oracle9i. It exists in text form and can be modified in vi editor. For oracle9i and later versions, oracle can use the server parameter file (spfile, system parameter file) to replace the

The little things found during program tuning today. In Windows, if the key value is default null and ''is inserted, an error occurs. If mysql is running in Linux, the value of 0 in the same table is as follows: The table creation statement is the

An error occurred while opening the database startup Oracle in Linux today: ORA-00600: internal error code, arguments: [keltnfy-ldmInit], [46], [1], [], [], [], [], [], [] Later, I checked the information and figured out that I changed the

The MySql4.1.7 password algorithm is different. You can make the following options: 1) Use PHP5 and php_mysqli.dll instead of the previous php_mysql.dll. 2) Change the MySql password to the original algorithm (this article introduces) I have been

A table is one of the most basic objects in an Oracle database. From the ground up, the base object is very important for databases. Whether the design is reasonable is directly related to the database performance. From the Oracle database cainiao

Although MySQL 5.1 has released GA after 5.1.30, it is clear that the development of MySQL 5.0 series has not been stopped officially, A new community stable version 5.0.75 has been released on the MySQL ftp server this morning. This is a bug fix

Today's optimization has been transformed to optimization wait (waits). In reality, the most fundamental appearance of performance optimization is also concentrated on IO, which is the most important aspect that affects performance, waiting in the

Purpose1. Table scanning before index creation1. Which data blocks are scanned?2. Relationship between data blocks3. Physical read4. Logical read5. Test the differences: full table scan and partial Table Record Scan6. Do I scan data blocks for

Today I also encountered a ORA-00257, although not exactly the same, but also almost, are flash_recovery_area is too small. The following is reproduced from the network. In the actual project encountered a ORA-00257 error (insufficient space error),

Today I tested how to recycle a large number of deleted space in MySQL (version 5.5.27 ).1. myisam table Optimize table tablename ;# Ii. innodb table (independent tablespace) -- innodb-file-per-table A. Method 1: optimize table m; Mysql> delete from

Compiler path configuration under Codeblocks: I feel that I can understand the compiler compilation and linking mechanism. I am not sure about it here. To put it simply, you need to add some options when compiling a program using the command line:

Let's talk about what they have in common: they are essentially an exclusive lock on resources, all caused by concurrency (if the database has only one session, it cannot be locked ). Next we will focus on their differences: First, they have

Pt-table-checksum installation: : Wget www.percona.com/downloads/percona-toolkit/2.2.2/percona-toolkit-2.2.2.tar.gz Tar xf percona-toolkit-{version}.tar.gz Cd percona-toolkit-{version} # enter the decompressed directory Vim README # view the