Oracle

The integrity of the data is used to ensure that database data follows specific business rules. In an Oracle database, you can use constraints, triggers, and application code (procedures, functions) to achieve data integrity in 3 ways. Today we

1, Redo Log Buffer Redo Log Buffer is a cache of database modification information stored in the SGA. This information is stored in the Redo entry (Redo Entry). The redo entry contains the necessary information to rearrange or redo the database

1. Concept (1) User: User (account) is a name defined in the database. (2) Privileged User: A privileged user is a database user with special permissions (SYSDBA or Sysoper). SYSDBA automatically has all the privileges of the DBA role, while

----Query the physical file for offline Select Name, Bytes, status from v$datafile where status = ' OFFLINE '; ----Query failed objects SELECT owner, object_name, object_typeFrom Dba_objectsWHERE status = ' INVALID 'and owner not in (' SYS ', '

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

First download from the Internet: 　　[oracle@jumper]$ wget http://www.realvnc.com/dist/vnc-4.0-x86_linux.tar.gz --10:34:32--　http://www.realvnc.com/dist/vnc-4.0-x86_linux.tar.gz 　　　　　 => `vnc-4.0-x86_linux.tar.gz' Resolving www.realvnc.com... done.

Date data type This data type is so familiar that we think of date types when we need to represent dates and times. It can store months, years, days, centuries, hours, minutes, and seconds. It is typically used to indicate when something has

1, Table space: Table space is the logical division of the database, a table space belongs to only one database. Each table space consists of one or more data files. Data from other logical structures in the tablespace is stored in these data files.

Oracle Profiling Functions Overview Profiling functions in Oracle are similar to aggregate functions, but for each set of records, no matter how many rows, the aggregate function returns only one row of values, and the parse function returns a

The external table is the table structure that is stored in the data dictionary, and the table data is stored in the OS file's tables. By using an external table, you can not only query the data of the OS files in the database, but also use the

Objective: To clone the library with Rman on the same machine Environment: RedHat 4 + Oracle 10g Master Library Name: DB01 Clone Library Name: Clonedb 1, the main library db01, with Rman for backup (datafile, controlfile, Archivelog file) 08:49:

Rman Learning Summary as follows, has been tested run, no problem. 1. Set the database as the archive mode Check Archive mode Select Log_mode from V$database; If noarchivelog, it needs to be set to archive mode Shutdown immediate; Startup

Often have friends ask the row and column conversion problem, the message board also has such a question. In fact, the use of analytic functions to deal with is a good way to turn over Tom's book, one of the examples included here. For example, to

Oracle partitioning and indexing can be said to be its own bright spot, and you might say there are other databases, yes, but Oracle's kind of performance convenience can be said to be more humane, the following we through the experiment to

Oracle Data Import Export IMP/EXP is equivalent to Oracle data restore and backup. The EXP command can export data from a remote database server to a local DMP file, and IMP commands the DMP file to be imported locally into a distant database server.

In the installation directory, such as: E:\Oracle\Ora81\network\ADMIN under the use of WordPad or Notepad to open the Tnsname.ora file, the contents of the file may be as follows: TEST. softone.com = (DESCRIPTION = (Address_list = (address =

Objective The vast majority of Oracle database performance problems are caused by unreasonable database design, only a small number of problems rooted in db Buffer, Share Pool, Redo Log buffer and other memory module configuration unreasonable, I/O

Check a system, accidentally found the database v$session_longops time far more than the system time. The results of the query are as follows: [ORACLE@DATASD ~]$ Sqlplus/as SYSDBA Sql*plus:release10.2.0.3.0-production on Monday December 20 14:57:0

In the actual production environment we may need to quickly replicate the existing database, also hope that the new library and the original library is not the same name, or we need to replicate the production library to do research and development

Backup strategy for customer deployment, replacing important information related to customers Database backup Scenario Deployment process: Considering that the system is a high-availability system (7x24), it uses Rman to warm up the DB, and the