Oracle

Buffer Cache is an area of the SGA area that is specifically used to store copies of blocks of data that are read from the data file. If the Oracle process finds that a block of data that needs to be accessed is already in the buffer cache, it reads

Under what circumstances is a clustered table used? Do you want to compare the performance of the overly-area and clustered tables? 1, the so-called clustering refers to a column as a benchmark, the same cluster key values of all the rows are

This article refers to the different versions of the information on the web, and then their own in the cent0s6.3 x86 and x64 two virtual environments are completed, the installation is the corresponding system of Oracle 11gx86 and x64 two versions,

Flashback Data Archive (Flash back archive)The rollback information for the Undo table space Record, although it can provide a back-flash query, but for a long time, this information will be overwritten, in fact, as long as the transaction is

Oracle temporary table feature Description: Temporary tables in Oracle are global and need to be created at database design time, not when the program is used. Each login user uses the same temporary table, but does not see each other's data, which

Summary: This article begins with a detailed introduction to the concept of shared pool in Oracle and the memory structure included. It then provides an in-depth overview of Oracle's management mechanisms for shared pool. Finally, the paper

What is an Oracle character setAn 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 use

Under Linux, kernel may also be installed without changing the same procedure as SolarisBut the kernel parameters must be changed under Solaris, and my next lesson is for Solaris Sparc/intel 'In/etc/system finally joined these:Set

oracle| Function | speed When data is stored in a normal table, the records are physically saved to the allocated block in the order they were inserted into the database. For example, if you have a table for storing employee information, the

oracle| Page | data | database | Display again is to organize the data to be placed in Oracle database $serial =md5 (rand ()) (uniqid); $ref = ""; $id = $PHP _auth_user; $ip = $REMOTE _addr; $msg =base64_encode ($msg); $flag = "1"; $query = "INSERT

Mysql|oracle| Program Author: Yu Feng There are many applications, just started with the MySQL database can basically achieve a variety of functional requirements, with the increase in the number of users, data, MySQL gradually become overwhelmed

oracle| Recovery | control | data --------------------------------------------- Experimental platform: Windows + Oracle 10.1.0.2.0 Author:ningoo 2005-03-26 -------------------------------------------- After the control file is backed

oracle| Quick Start Preface This article mainly introduces the common methods of Rman, including some of the author's own experience, the experiment is basically all in the win 2K and Oracle 8.1.6 Environment Test success (because this environment

Oracle   Virtual field 133. 　 Currval and Nextval Create a sequence created SEQUENCE empseq for the table ...; 　 SELECT Empseq.currval from DUAL; Inserts the numeric values of the sequence into the EMP values (empseq.nextval, ' LEWIS ', ' clerk ', 79

And_equal is a specific operation supported by Oracle that can combine multiple Single-column indexes (index merge) to output query results. At the same time and_equal can be enforced by hints, with a minimum of two indexes specified, up to 5. The

Oracle provides ref CURSOR, which enables the ability to pass result sets between programs, and can also implement bulk SQL using ref CURSOR to improve SQL performance. Use the Scott User's EMP table to implement the following test cases: Sql>

In the previous article, I introduced how to use Oracle 10g's Virtual Private database feature (VPD) to hide a column of data TechRepublic members Brooklynpennypincher suggested that I write a comparison article about VPD and relational views. The

Oracle databases have always had the ability to audit operation types against the database and to keep audit trails in a system table. This table is named Sys.aud$ and is located in the data directory. In some operating systems, you can also write

The trial found that Oracle does not support full outer join query rewriting, even if materialized views and query statements match exactly. In the 10g test found that for all outer joins, the creation of a statement-consistent materialized view

A The base of RMAN restoration and recovery In the use of Rman, restore and restore are two different concepts. Restore: Refers to accessing a previously generated backup, getting one or more objects, and then restoring those objects somewhere on