list down any four ways to identify the session in World Wide Web? (2)
1. Using Time-contiguous Log Entries 2. Using Transient Cookies 3. Using HTTP's secure sockets layer (SSL) 4. Using session ID Ping-pong 5. Using Persistent Cooki
What is Web Data Warehouse? (2)
Web Warehousing can be used to mine the huge web content for searching information of interest. It’s like searching the golden needle from the haystack. Second reason of Web warehousing is to analyze the huge web traffic. This can be of interest to Web Site owners, for e-commerce, for eadvertisement and so on. Last but not least reason of Web warehousing is to archive the huge web content because of its dynamic nature.
How time contiguous log entries and HTTP secure socket layer are used for user session identification? What are the limitations of these techniques? (3)
A session can be consolidated by collecting time-contiguous log entries from the same host
(Internet Protocol, or IP, address). In many cases, the individual hits comprising a session can be consolidated by collating time-contiguous log entries from the same host (Internet Protocol, or IP, address). If the log contains a number of entries with the same host ID in a short period of time (for example, one hour), one can reasonably assume that the entries are for the same session.Limitations•This method breaks down for visitors from large ISPs because different visitors may reuse dynamically assigned IP addresses over a brief time period.•Different IP addresses may be used within the same session for the same visitor. •This approach also presents problems when dealing with browsers that are behind some firewalls.
Nested loop efficient way of accessing the inner table? (3)
Answer: Typically used in OLTP environment. Limited application for DSS and VLDB In DSS environment we deal with VLDB and large sets of data. Traditionally Nested-Loop join has been and is used in OLTP environments, but for many reasons, such a join mechanism is not suitable for VLDB and DSS environments. Nested loop joins are useful when small subsets of data are joined and if the join condition is an efficient way to access inner table
Two tables were given one was employee table and other exception table with attribute IsAgeValid. Sql query was required to find the outliers not having age between 26 and 75 and set the dirtyBit in exception table to 0?5 marks Answer:Select * From (Select * From Employee Where DirtyBit= 0)IsAgeValid Where (Age <26 And >75))
Why students allowed by company to visit company data warehouse? (5)