What are the different models used in cluster analysis?

Correct Answer: Cluster analysis is used to define the object without giving the class label It analyzes all the data that is present in the data warehouse and compare the cluster with the cluster that is already running It performs the task of assigning some set of objects into the groups are also known as clusters It is used to perform the data mining job using the technique like statistical data analysis It includes all the information and knowledge around many fields like machine learning, pattern recognition, image analysis and bio-informatics Cluster analysis performs the iterative process of knowledge discovery and includes trials and failures It is used with the pre-processing and other parameters as a result to achieve the properties that are desired to be used

Correct Answer: Bitmap indexes make use of bit arrays (bitmaps) to answer queries by performing bitwise logical operations Bitmap indexes are useful in the data warehousing applications Bitmap indexes have a significant space and performance advantage over other structures for such data Tables that have less number of insert or update operations can be good candidates The advantages of Bitmap indexes are: - They have a highly compressed structure, making them fast to read - Their structure makes it possible for the system to combine multiple indexes together so that they can access the underlying table faster The Disadvantage of Bitmap indexes is: - The overhead on maintaining them is enormous

Correct Answer: Data cleaning is also known as data scrubbing Data cleaning is a process which ensures the set of data is correct and accurate Data accuracy and consistency, data integration is checked during data cleaning Data cleaning can be applied for a set of records or multiple sets of data which need to be merged Data cleaning is performed by reading all records in a set and verifying their accuracy Typos and spelling errors are rectified Mislabeled data if available is labeled and filed Incomplete or missing entries are completed Unrecoverable records are purged, for not to take space and inefficient operations

Correct Answer: At the time of updating the data warehouse, a lookup table is used When placed on the fact table or warehouse based upon the primary key of the target, the update is takes place only by allowing new records or updated records depending upon the condition of lookup The materialized views are aggregate tables It contains summarized data For example, to generate sales reports on weekly or monthly or yearly basis instead of daily basis of an application, the date values are aggregated into week values, week values are aggregated into month values and month values into year values To perform this process aggregate function is used

Correct Answer: Data Mart is a data repository which is served to a community of people who works on knowledge (also known as knowledge workers) The data resource can be from enterprise resources or from a data warehouse

Correct Answer: Cascade: - Cascade process involves taking values from various other prompts - The result is a single report - The result is used when a criteria is to be implemented Drill Through: - Drill Through process is implemented when navigation from summary to detailed information - Drill Through has a parent and a child report - Data of another report can be seen based on the current details of data

Correct Answer: NO_CACHE ? It is used for not caching values PRE_LOAD_CACHE ? Result column preloads and compares the column into the memory, prior to executing the lookup PRE_LOAD_CACHE is used when the table can exactly fit in the memory space DEMAND_LOAD_CACHE ? Result column loads and compares the column into the memory when a function performs the execution DEMAND_LOAD_CACHE is suitable while looking up the highly repetitive values with small subset of data

Correct Answer: - Scheduling and executing the batch jobs - Configuring, starting and stopping the real-time services - Adapters configuration and managing them - Repository usage, Job Server configuration - Access Server configuration - Batch job publishing - Real-time services publishing through web services

Correct Answer: - The process of combining data from different resources - The combined data is provided to the users with unified view - Information from different enterprise domains are integrated ? known as Enterprise Information Integration - Useful for merging information from different technologies among enterprises - The sub areas of data integration are 1 Data Warehousing 2 Data Migration 3 Master Data Management

Correct Answer: Following are the benefits of data integration: - Makes reporting, monitoring, placing customer information across the enterprise flexible and convenient - Data usage is efficient - Cost Effective - Risk adjusted profitability management as it allows accurate data extraction - Allows timely and reliable reporting, as data quality is the prime technology for business challenges