It is common practice to allow columns for which the corresponding attribute value may sometimes not be available to contain a null. Null is not a value as such, but represents the absence of a value. Columns that may contain nulls are sometimes called nullable columns. Instead of allowing a col
Other News
Oracle Tip: Solving directed graph problems with SQL, part 2
Part one discussed using SQL to solve directed graph problems. Another kind of directed graph is a state machine. In a state machine, each node is called a state and represents the current status of a system, object, or variable. There are vectors between each state that represent a change in state
Using Service Data Objects with Enterprise Information Integration technology
(C.M.Saracco, Jacques Labrie and Stephen Brodsky) Combining Enterprise Information Integration (EII) technology with Service Data Objects (SDO) helps object-oriented programmers easily work with a wide variety of heterogeneous data sources and reduces the complexity of integrating disparate data.
The DTA: A Jack-of-All-Trades Hero
(Brian Moran) In the land of Not So Long Ago, the DBA was the hero of the IT shop. The DBA determined the content, internal structure, and access strategy for the IT shop’s database; defined security and integrity rules; and monitored performance. But in the land of Here and Now, the up-and-coming h
Diskeeper Can Boost Your SQL Server’s Performance
(Brad M. McGehee) One of the biggest hardware bottlenecks of any SQL Server is disk I/O. And anything that we, as DBAs, can do to reduce SQL Server’s use of disk I/O will help boost its performance. Some of the most common things DBAs do to reduce disk I/O bottlenecks include: –Tuning queries to
Trickledown Namespaces?
(John E. Simpson) Why aren’t my namespaces being inherited? Some time ago I read something about namespace declarations which said, “The namespace declaration given for the current element is also valid for all its children and descendants.”
SQL Server 2000 Cluster Does Not Install on Windows Server 2003-Based Computers Where Terminal Services Is Installed
You cannot install SQL Server 2000 on a computer that runs Microsoft Windows Server 2003 and that has Terminal Server installed on a server cluster. After you provide all the correct information to SQL Server 2000 Setup (and provide the VirtualServer name, IP address and licensing information), you
Populate Table Control dynamically from DataReader according to format given in an XML file
(Muhammad Musa Ali) I have to use a datareader which will be passed to my method by some other method. It contains the records that a certain search brought. I have to display the results of that search into a given asp:Table control. I do not know anything about the fields of the records contained
Working XML: UML, XMI, and code generation, Part 3
The third article on UML modeling and XML further refines the conversion stylesheet with the introduction of stereotypes and tags. These are extension mechanisms for UML that are used to store implementation information in the model. The last two installments of the Working XML column have explo
Don’t Let Referential Integrity Degrade Your Database Performance
(Boris Milrud) Oracle databases provide a powerful mechanism for enforcing business rules, called referential integrity (RI), which is implemented either via a declaration of foreign key (FK) constraints ("declarative RI") or via triggers. It is almost impossible to find an Oracle database with no d