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One, what is a distributed database The Distributed Database System (ddbs:distributed) is developed on the basis of centralized database system. is a combination of database technology and network technology products. There are two kinds of

BFILE binary files, stored in an operating system file outside the database, read-only. Treat this file as binary. BLOB binary Large object. A large object stored in a database, usually a file such as an image sound. CLOB large-character object.

server| Data | database Lock is a very important concept in network database, it is mainly used to guarantee database integrality and consistency under multi-user environment. The basic theory of lock used in various large databases is consistent,

or refer to the previous example: Http://blog.csdn.net/kunshan_shenbin/archive/2008/09/02/2864883.aspx Modify the User.hbm.xml file as follows: "-//hibernate/hibernate Mapping DTD 3.0//en" "Http://hibernate.sourceforge.net/hibernate-mapping-3.

For the dbms_random described in the previous article. In the case of the value function, it is obvious that the call to the function occurred during the execution of the SQL statement. However, if you look at the processing of constants in SQL

Example Description: (1) Create 2 table spaces first. Create tablespace user01 datafile ' +dg1 ' size 1M; Create tablespace user02 datafile ' +dg1 ' size 1M; (2) Create a table on each table space. CREATE TABLE Scott.customers (cust_id

One, the spy of the binding variable (PEEK) 1, Oracle in the processing of SQL with binding variables, only in hard parsing will "pry" the value of the binding variable in SQL, and then based on the value of the detected to determine the entire SQL

Acronisdiskdirectorsuite is a powerful set of hard disk management tools that can be partitioned and used to repartition or tune existing hard disks without losing data, and to fix data in damaged or deleted partitions. In addition, the software is

Cookie management is an unavoidable problem in Android apps. I would like to make some humble remarks here. Let's look at where the cookie might be stored. 1.Httpclient stores the cookie content at the time of the request, where the storage

Js In any web-based application, the program logic requires the user to submit information that needs to be validated, and the creator of the application can detect the data in two ways. The first approach is to validate on the client, even before

From the composition of the SGA of Oracle, it is highly recommended to use parameter bindings. Using parameter bindings makes it possible to use the share Pool efficiently, which can significantly improve performance by not having to harden the

Start from a problem Recently, the bank of this matter more serious ah, many depositors of the money in the bank, it disappeared, and the bank does not ask, said the user's responsibility, litigation, users can also lose, this is "socialism." Let's

DBMS_STREAMS_ADM provides three procedures for creating a table space-level replication environment: Maintain_simple_tts: Replication of a single table space Maintain_tts: Replication of multiple table spaces Pre_instantiation_setup and

oracle| Tips Author: Liu Yingbo Collection and finishing Time: April 29, 2004 Reprint please indicate the source, thank you! 1. Find Useless index: DML performance is low, one of the most serious reasons is the existence of useless indexes. All

Use PHP to complete SVN operations, including copying, viewing lists, deleting, moving, creating catalogs, viewing diff, updating, merging, submitting, getting status, getting commit log, getting the current version number operation. Test passed in

Third, the existing O/R mapping product introduction O/R mapping has been a long time, a lot of products: Java has hibernate, JDO and so on. Net has objectspaces, grove.net, Ojb.net, Atomsframework, Objectz.net, OPF. NET and so on. 1, Hibernate

SVN installation The SVN server operates in 2 ways: Standalone servers and Apache. Svnserve is lightweight and simpler than Apache, and Svnserve is included in subversion, so as long as subversion is installed it's equivalent to installing a small

1, select the most applicable field properties MySQL can support a large amount of data access, but generally speaking, the smaller the table in the database, the faster the query executed on it. Therefore, in order to achieve better performance

Copying data from one table to another, inserting new data, or replacing old data is a problem that every Oracle DBA will frequently encounter. In the years before the oracle9i, we have to find out whether there is old data, if useful update

Database concurrent access, where two or more users access the same data at the same time, is the biggest problem for the database engine to design and implement a moderate response. A well-designed, performance-capable database engine can easily