Oracle

The former is easy to locate. All operating systems allow us to look at CPU-intensive tasks. These tasks can be traced back to a specific user, a specific application module. CPU-intensive modules are generally caused by poor code and/or structure,

This article mainly introduces the Oracle database startup and shutdown methods, the need for friends can refer to the next First, start data$sqlplus "Sys/pass as SYSDBA"Sql>startup Second, start the listenerafter the database is started, if the

Data Guard offers two main services:1 Redo Transport service: The Primay end of the redo log transmission to one or more standby destinations.2 Redo Application Service: The redo log which is transmitted from the Primay end is applied to the standby

Oracle does not have such features as the self-adding fields, but it can be implemented by triggers (trigger) and sequences (sequence). First build a test table: CREATE TABLE Userlogin( ID Number (6) is not NULL, Name VARCHAR2 NOT NULL primary

Distinct this keyword to filter out the extra duplicate records only one, but often use it only to return the number of records not duplicates, rather than using it to return all the values not to be recorded. The reason is that distinct only use

1, the use of Oracle user login, connect the database [Oracle@wuzj ~]$ Sqlplus/nolog Sql*plus:release 10.2.0.1.0-production on Thu Feb 26 12:06:29 2009 Copyright (c) 1982, +, Oracle. All rights reserved. Sql> Conn/as SYSDBA Connected. View

When diagnosing a problem with a lock, check with the holder, the person who is blocked. Often is very troublesome, if you do not accumulate the script, rely on Manual Check to check a lot of tables, such as V$lock,v$process p, v$session s,

Recently saw a lot of people talk about TNS or database can not log in and so on, simply summed up the following dongdong. First of all, Oracle's network structure, to complex to say can add encryption, LDAP and so on. There is no discussion here,

This article is a detailed analysis of the implementation of the Oracle Query and deletion job SQL, the need for a friend under the reference Query and delete duplicate records of SQL statements 1, find redundant records in a table, duplicate

Oracle Database backup: --Keep the backup record of the most recent week; = = = Text: = = Start ============== Echo Set backup file Folder ... Set "Tbuf=e:cwaybackup" echo Sets the backup file name (named after the day of the week, that is,

1, must set the undo retention time is large enough to be able to reconstruct the required flash back data The ALTER SYSTEM SET undo_retention= seconds value is the number of seconds that the UNDO data is persisted. Flashback view is

What is an Oracle character set An Oracle character set is a collection of symbols that are interpreted by a byte of data, having a size and a mutual containment relationship. Oracle's support for the national language architecture allows you to

Comments: Oracle Table Space Recovery scheme includes user table space, temporary table space, system table space, rollback table space, control files and other recovery schemes, in which user table space and rollback table space, control file

Oracle database Export and re-import one, export database? 1 2 3 4 5 6 1, the database TEST completely exported, user name Scott password Tiger, exported to d:testdb.dmp: [plain] exp scott/tiger@test file=d:testdb.dmp full=y 2, To

Oracle Data Guard Create a physical standby database Create a physical repository Machine name A1 A2 ip:192.168.1.10 192.168.1.20 Net_name A1 A2 SID A1 A2 Db_unique_name A1 A2 Note: Create the database A1 on the master node, install only

This article mainly introduces TM lock in Oracle, understand that when we access the same table object in the database through SQL statements, if more than one user operates on the same table object, it may result in inconsistent data and data

1. To optimize the query, avoid full-table scanning as far as possible, and first consider establishing an index on the columns involved in the Where and order by.2. Avoid null-valued fields in the WHERE clause, which will cause the engine to

Tag:com    change    int    rollback    idle    Disk     server     own    serial    -1. --System parameter configuration connect Sys/[email protected]_link as SYSDBA select * from Dba_profiles where resource_name like ' failed_l　　Ogin_attempts% ';　　

After executing an SQL statement for the first time in Oracle, the SQL statement is parsed hard, and the execution plan and parse tree are cached in the shared pool. It is convenient to perform this SQL statement again without having to do hard

In the oracle10g and 11g versions, the ORACLE default log archive path is the Flashback recovery area ($ORACLE _base/flash_recovery_area). For this path, Oracle has a limitation, that is, the default is only 2G of space, and not just the default