Database Administrator

Use ctrl + c to exit the current status output mode. Run the following command: expdp userid/password attach = job_name to connect to the currently running import/export task. You can use job_name to specify the task name.1. add_file = test _ % U.

1. Understand When logws write redo logs into the redo log file in the redo log buffer to understand commit; Write when redo log buffer 1/3 is full Write at commit When a log switch occurs, write Write when the generated redo is 1 MB When DBWN

Recently, you need to manually refresh a materialized view after the documents are successfully submitted. The solution was to call dbms_refresh.refresh ('materialized view name') on the After Update trigger of the table. An error was reported

System and object permissions for Oracle databases: Alter any cluster: modify the permissions of any cluster Alter any index Alter any role Modify permissions of any role Alter any sequence Alter any snapshot Alter any table Alter any trigger Alter

In compiling PL/SQL, it may take several seconds to pause the program and continue execution. Check that dbms_lock.sleep (10) is provided in Oracle. However, you must install the dbms_lock package on your own, the demo is as follows: C: \

After compiling and installing MySQL, you can use gdb to track the execution of the mysql server. Gdb -- args/usr/local/mysql/libexec/mysqld (Gdb) B mysql_selectBreakpoint 1 at 0x8228b7d: file SQL _select.cc, line 2315.(Gdb) B my_net_readBreakpoint 2

Create TableMyinfo (myname varchar2 (10), passwdVarchar(10 )); Based on the above table myinfo PL/SQL (procedural language/SQL ):Oracle is an extension based on the standard SQL language. In PL/SQL, You can nest SQL statements, define variables,

1 move Experiment SQL> create table my_objects_move tablespace ASSM as select * from all_objects where rownum Table created   SQL> select value 2 from v $ mystat, v $ statname 3 where v $ mystat. statistic # = v $ statname. statistic # 4 and v $

1.1.Log & Checkpoint InnodbThe transaction log of isRedo log, AbbreviationLog,Save in Log FileIb_logfile *. Innodb also has another log Undo log, but the Undo log is stored in the shared tablespace (ibdata * file

This article analyzes the problem of slow MySQL database servers and proposes corresponding solutions. 1. Check the system status Check the status of the system by using some operating system tools, such as CPU, memory, swap, and disk utilization.

Recently, Oracle 11g exp command was used to back up the database and restore the database. It was found that the table that has never inserted data before the export was not exported. Similar problems have not been found before when I was using 9i

How To Connect C to the MySQL database in Linux: # IncludeStdlib. h> # IncludeStdio. h> # IncludeMysql. h> Int main (int argc, char * argv []) { MYSQL * conn_ptr; Conn_ptr=Mysql_init(NULL ); If (! Conn_ptr ){ Fprintf

1.Set the total number of lines displayed on the page   1)View the currentPagesize,The default value is14: SqlplusCode 1.Show pagesize;   2)SetPagesizeSet100,You can display more than enough rows at a time.: SqlplusCode 1.Set

1. Shrink Oracle10g Database files: 1.1 questions: A database contains millions of data records. After the Delete statement is used to Delete most of the data, the space occupied by the database files will not be reduced to free up extra space. For

Oracle in Linux is running after installation. Run ps-ef or top-u oracle. You can see the processes run as Oracle users. On the graphic interface, run $/usr/share/oracle/oracle11gR2/product/11.2.0/dbhome_1/sqldeveloper. sh to display the free Oracle

The Oracle password file is used to store the passwords of all users who connect to the database with the sysdba or sysoper permission. to remotely connect to the database with the sysdba permission, you must use the password file. Otherwise, you

Some time ago, when I encountered such a problem, one day I suddenly encountered #2013-Lost connection to MySQL server at 'reading initial communication packet 'during database backup ',System error: 0Pay attention to the red part. Different error

Creating tables in Oracle to hook the same or consistent tables can also be used in many cases. Convenient. For example, a department table exists as follows: SQL> select * from dept;       DEPTNO DNAME          LOC   ------ --------------

Oracle 11g Release 1: http://www.oracle.com/technology/software/products/database/index.html RHEL5 under the ASMLib2.0: http://www.oracle.com/groovy/global/cn/tech/linux/asmlib/index.htmlopen the page, will find a Red Hat Enterprise Linux 4 AS (x86)

Sys @ DEX>Select*FromV $ statnameWhere Name Like '% Sort %'; STATISTIC #NAMECLASS STAT_ID ---------------------------------------------------------------------- 565 sorts (memory) 64 2091983730 566 sorts (disk) 64 2533123502 567 sorts (Rows) 6