Database Administrator

1. If the AUTO_INCREMENT field exists in the mysql table, the AUTO_INCREMENT field will not be automatically initialized to 0 after the data is cleared (delete from), but will still start auto-increment after the records are cleared, manual

All characters with n are unicode encoded, and letters and Chinese characters are in 2 bytes. Char fixed length. The varchar length is not fixed. Differences between char and varchar: The char type in the database is used to store fixed-length

1. Check the oracle instance status: selectinstance_name, version, status, database_statusfromv $ instance; 2. Check the oracle listening process: $ lsnrctlstatus 3. $ ps-ef | grep "ora _" | grep-vgrep Oracle Data File writing process, the output is:

Today, I suddenly found that the mysql database is down. InnoDB database problems, but cannot determine which database the problem is. Later, according to The searched content, rename ibdata1 under/var/lib/mysql to ibdata to solve the problem. 03:59

Chapter 2: using data processing functionsLike almost any other computer language, SQL supports the use of functionsTo manipulate data. Functions are operations usually saved med on data, usuallyTo facilitate conversion and manipulation.Like most

Pasted online 1. connect by prior recursive algorithm in oracleSelect... from tablename start with condition 1 Connect by condition 2 Where Condition 3; Example: Select * from table Start with org_id = 'hbh1_wgwpy' Connect by prior org_id

-- ===================================================== ============== -- LOGGING mode (LOGGING, force logging, NOLOGGING) -- ===================================================== ============== 1. LOGGING modes (LOGGING, force logging, and

Environment: centos 5.6 oracle 11g r2 Primary: 192.168.8.132 str1.example.com str1 master database sid primary Standby: 192.168.8.131 str2.example.com str2 standby database sid standby Oracle 11g software installation

Centos 5.6 x86_64 First, you need to install the required package: Yum install gcc-c + + gcc-g77 autoconf automake zlib * fiex * libxml * ncurses-devel libmcrypt * libtool-ltdl-devel * make cmake-y Then add the user: # Groupadd mysql #

1) Start When you enable the system by enabling the power switch or using the reboot and shutdown commands, the following events may occur before the system is available: 1, ROS kernel initialization stage The ROS kernel resides in the

Database backup and recovery:Note:For oracle databases installed on windows, when using the exp BACKUP command, enter the bin directory in dos.For oracle databases installed on linux, after environment variables are configured, they can be directly

1. First introduce what is HBA. The HBA mentioned here is the full name of fc hba, that is, the Fiber Channel Host Bus Adapter. In an FC network, a host, such as a server, needs to use an interface card to connect to an FC network or a FC storage

AIX: 1. Obtain the Optical Fiber Device connected to the AIX Host: # Lsdev-Cc adapter-S a | grep fcs Fcs0 Available 09-08 FC Adapter Fcs1 Available 09-09 FC Adapter Two Optical Fiber cards are displayed. Fcs0 and fcs1 2. view the WWN Number of the

Http://boylook.itpub.net/post/43144/520539;Well, since the last experience, we have to pull rowid in Table creation during the experiment to eliminate interference:SQL> create table t2 (ctn varchar2 (10), num number, r rowid );Table created.SQL>

1. Mount the Linux system CD Mount/dev/cdrom/media 2 switch to/etc/yum. repos. d/ Cd/etc/yum. repos. d/ 3. modify the configuration file Cprel. debuginfo. repoyum. repo. bak (Backup) Cpyum. repo. bakyum. repo rename) Vimyum. repo

Two hosts Hostname: linux-web ip: 10.5.5.23 Hostname: linux-mysql ip: 10.5.5.27 Host1: linux-web Vim/etc/my. cnf Server-id = 1 Log-bin = master-bin Master-host = 10.5.5.27 # hostname linux-mysql Master-user = slave # The

================================= Database-related concepts ====================== ==================== Database development stage:1. In the manual management phase, data is managed by writing on text or 10 tapes.Disadvantage: it is not conducive to

Struggling with elementary Web development, both hibernate and basic jdbc involve a coding problem. After all, this set of programming was invented by the foreign bank of lunjia. I had to bow my head in the Greater China Program, few gossip.

Environment: Sys @ ORCL> select * from v $ version; BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.1.0-Prod Sys @ ORCL>! Uname Linux (1) modify the Control File

E @ host10g ~] $ Netca OracleNetServicesConfiguration:Xlib: connectionto ": 0.0" refusedbyserverXlib: Noprotocolspecified Java. lang. NullPointerExceptionAtoracle. ewt. lwAWT. BufferedApplet. (UnknownSource)Atoracle.net. ca. NetCA. (UnknownSource)