Database Administrator

1. Oracle CREATE OR REPLACE FUNCTIONSETSTATE (OLDVALUE VARCHAR2, pos number, SVALUE VARCHAR2) RETURNVARCHAR2 IS RETURN_VALUE VARCHAR2 (20 ); Len number (8 ); I NUMBER (8 ); TEMP_VALUE VARCHAR2 (1 ); BEGIN LEN: = LENGTH (OLDVALUE ); If pos>

Add recordInsert into Table Name (field name, field name) VALUES (value, value );Delete recordDelete from table name WHERE condition (distinct Al can be left blank)Modify recordUPDATE table name SET field = value, field = value WHERE ConditionQuery

I learned a few commands when I got in touch with Oracle and changed the password of the system user. After a few days, I forgot + _ + .. The following describes how to unlock the system user and restore the password. 1. First, use the sys user to

Modify the corresponding Kernel Parameters Kernel. sem = 250 32000 100 128Kernel. shmmax = 2147483648Kernel. shmall = 4194304Kernel. sem = 250 32000 100 128Net. ipv4.tcp _ rmem = 4096 4194304 4194304Net. ipv4.tcp _ wmem = 98304 4194304 4194304Net.

When I got off work, the company's database was suddenly blocked. A buf table could not extract more than 20 million data and changed the program. The effect was not obvious. Since Oracle was restarted once before, I still want to restart oracle

Oracle 10g r2 rac database modification archive to ASM1. Create related space directories on asmExport ORACLE_SID = + ASM1AsmcmdMkdir arch1 arch2ASMCMD> pwd+ DATA/RACDB/archiveASMCMD> lsArch1/Arch2/ASMCMD>2. modify a node in the mount status[Oracle @

Recently, the company is making a NoSQL model selection, and has made the following Rough Analysis and Comparison on several common NoSQL databases over a week. Glossary: Distributed Storage Unit: in distributed storage, large data files are usually

In applications, a table's primary key is often paid with an automatically increasing number, for example, the sequence of Oracle, and the expected primary key value after insertion. The following describes the related methods. 1. Use the returning

1 table_exists_action parameter description When using imp for data import, if the table already exists, drop the table before importing. When you use impdp to import a database, if the table already exists, there are four processing methods: 1)

In the previous test environment, the device symbols were directly used to map the binding method. In this case, the hard disk was added due to insufficient space, as a result, the new hard disk occupies the original ocr/dev/sdb, which will cause

The old system has been operating normally and suddenly the database cannot be accessed, as shown below: Aix5.3 system with Oracle9i installed Log on to the aix system and find that the listener has been interrupted. Prepare to restart the database.

NoSQL has many advantages, Just 1. store any objects, images, files, and so on. 2. The same object storage is not restricted. That's enough for me to hug. So, go to ruby and check that there is a feeling that the consumer ID will gradually replace

Symptom: mysql crashes when mysqldump exports data or accesses a table or data.The log is as follows:InnoDB: Database page upload uption on disk or a failedInnoDB: file read of page 26400.InnoDB: You may have to recover from a backup.120217 15:45:53

1. Create the same directory as the 9i data file, control file, and redo file on the target server where Oracle 10g software is installed (the data files of the two databases must be in the same location) 2. Shut down the 9i source database, copy

Oracle 11g creates a function to obtain the current trace file Create or replace function current_trace return varchar2 Is V_file varchar2 (100 ); Begin Select par. value | '/' | ins. instance_name | '_ ora _' | pro. spid | '. trc' into v_file

I. Installation1. Download The mysql-5.1.54.tar.gz and unzip it to/root/mysql/mysql-5.1.54 directory2. Download The ahiguti-HandlerSocket-Plugin-for-MySQL-1.0.6-94-g98b14c3.tar.gz and unzip it to the/root/mysql/ahiguti-HandlerSocket-Plugin-for-MySQL-

Oracle dynamic SQL DBMS_ SQL built-in package Native Dynamic SQL Three common functions of Native Dynamic SQL Execute dynamic DDL or DML statements that do not contain Bound variables. Execute dynamic DDL or DML containing Bound variables

Quick MySQL installation and client Access authorization in Linux: Yum install mysql-server // install mysql server /Etc/init. d/mysqld start // start the mysql server --------------------------------- Client Access Authorization -----------------

The database cannot use the archive logs of Oracle when the set limit value is reached. The error message is: ORA-00257: archiver error. Connect internal only, until freed At this time, you can choose to move its log file to another place, and

At present, all major portal websites tend to use MySQL to a certain extent. In addition to the I/O/E campaign advocated by the Alibaba system, we must correct the earlier view that we have always despised MySQL, as a database practitioner, we must