Data mining is the process of finding useful new correlations, patterns, and trends by transferring through a high amount of data saved in repositories, using pattern recognition technologies including statistical and mathematical techniques. It is the analysis of factual datasets to discover unsuspected relationships and to summarize the records in novel methods that are both logical and helpful to the data owner.There are various transformations of data mining which are as follows −Flag normal, abnormal, out of bounds, or impossible facts − Marking measured facts with special flags can be completely beneficial. Some measured facts may be correct but highly ... Read More

Fact tables involve a composite primary key, which includes multiple foreign keys (one for each dimension table) and a column for each measure that uses these dimensions.Every data staging process must include a step for replacing the production IDs in the incoming fact table record with the data warehouse surrogate keys, for each dimension in the fact table. Other processing, computation, and restructuring may also be necessary.In the warehouse, Referential integrity (RI) defines that for each foreign key in the fact table, an entry continues in the equivalent dimension table. If you have a sale in the fact table for ... Read More

Data Warehousing is a technique that is mainly used to collect and manage data from various sources to give the business a meaningful business insight. A data warehouse is specifically designed to support management decisions.In simple terms, a data warehouse defines a database that is maintained independently from an organization’s operational databases. Data warehouse systems enable the integration of multiple application systems. They support data processing by providing a strong platform of consolidated, historical data for analysis.Data warehouses generalize and centralize data in multidimensional space. The construction of data warehouses contains data cleaning, data integration, and data transformation and can ... Read More

The simplest form of encryption is symmetric key encryption. This kind of encryption is also called private key encryption. With symmetric-key encryption, a single secret key can both lock the information and unlock the information.Symmetric key encryption is mainly interesting in two situations −Private encryption of data − The user encrypts data with a private key that the user does not reveal to anyone else. If the key is a good one, no one else can decrypt the data.Private encryption of data can have several uses in the data warehouse. Any data that is especially sensitive could be so encrypted. ... Read More

The directory server is a type of data warehouse of resources accessible on the related network. Resources such as database devices, individual databases, file repositories, transaction systems, file storage areas, printers, and people.The people descriptions include names and addresses, organization roles, e-mail addresses, and more. The directory server reveals selected items of information to legitimate, authenticated requesters. It is meant to be a useful, centralized, controlling resource for finding out how to communicate on the associated network.Many vendors have agreed on the LDAP standard for communicating with a directory server, and, thus, implicitly for implementing a directory server. The term ... Read More

The size of the desktop machine is based on the characteristics of the user and the related tool requirements. A casual user whose data required are met by HTML document through a Web browser needs only as much power as it takes to run the internet browser.On the other hand, a power user who develops complex queries and analyses from scratch will possibly need a more dynamic machine. There are some desktop related challenges which are as follows −Cross-Platform Support − Some organizations have Macintosh hold-outs in the marketing organization, and some organizations need UNIX stores in engineering and manufacturing. ... Read More

There are three basic parallel processing hardware architectures in the server market such as symmetric multiprocessing (SMP), massively parallel processing (MPP), and non-uniform memory architecture (NUMA).Symmetric Multiprocessing (SMP)The SMP architecture is an individual device with multiple processors, all managed by one operating system and all accessing the similar disk and memory area. An SMP machine with 8 to 32 processors, a parallel database, large memory (two or more gigabytes), good disk, and a good design should perform well with a medium-sized warehouse.The database needs to be able to run its processes in parallel, and the data warehouse processes need to ... Read More

There are various categories for hardware and operating system platforms which are as follows −Mainframes − The data warehouse is probably the one application to which this does not apply. Especially, the mainframe is not the first-choice platform for data warehousing.There are some successful mainframe-based data warehouses, most of them have been on the mainframe for various years and will be costly to move, or they are taking benefit of excess capacity, so the marginal cost is relatively low.The mainframe is not necessarily cost-effective for data warehousing. Administrative, hardware and programming costs are generally larger than on open system platforms, ... Read More

There are the following requirements for the server platform are as follows −Volatility − Volatility computes the dynamic characteristics of the database. It includes areas like how often the database will be updated, how much data changes or is replaced each time, and how long the load window is. Daily data is more volatile than weekly or monthly data.Customer churn rates can tell you how much your customer dimension will change over time. The interpretations to these questions have a direct force on the size and speed of the hardware platform. Data warehouses carry the complete brunt of both the ... Read More

There are various features of Query Formulation which are as follows −Multipass SQL − It can be used to evaluate comparisons or to correctly compute nonadditive measures in report break rows, the query tool should divide the report down into multiple queries that are processed independently by the DBMS.The query tool automatically combines the results of the separate queries intelligently. Multipass SQL also enables drilling across to multiple fact tables in several conformed data marts, possibly in different databases.For instance, sales and costs might be in multiple databases, but considering they share equal dimensions, such as Organization and Period, it ... Read More