Data warehousing is the technological act of storing massive amounts of data for use in running reports. Many different industries utilize this technology and warehouses are often set up similarly. Because warehousing is similar across the board, data warehouse interview questions are very direct. Interviewees can expect to be quizzed about a general understanding of data warehousing, level of expertise, understanding of various processes, and questions that unveil the interviewee's personality.
Attaining a better understanding of an interviewee's general warehousing knowledge is a big portion of data warehouse interview questions. These questions will involve general terms and practices to ensure the person being interviewed has the appropriate level of experience to handle the job. Interviewers often ask what the difference is between online analytical processing (OLAP) and online transaction processing (OLTP); these two processes are key elements of warehousing data. Another general knowledge question is to ask what a lookup table is used for or what an operational database store (ODS) does.
Data warehousing is a complex process; data warehouse interview questions frequently probe the interviewee to determine what level of complexity they understand. A question asking why data and dimensional modeling are important is common because these processes are essential to proper informational storage. Asking why an OLTP database design is not a good idea is another complicated question designed to test the interviewee's knowledge of the entire process.
Since data mining is a major part of warehousing, an interviewee should expect to be asked many data warehouse interview questions on this process. Asking about the advantages of data mining over more traditional methods is one likely question. Interviewers are also frequently curious about specific processes involving data mining. A prospective job candidate might have to give an example of when data mining was used in a work situation and the result of the project. Interview questions can also be turned around; instead of asking for a positive experience, a candidate might be asked what her or she dislikes about mining and how it could be changed.
Personal information is another likely topic of data warehouse interview questions. In most situations, these will not involve questions about work and family life, but rather how an interviewee's personality fits with the team. Questions such how the individual handles stress and pressure are common and usually require examples. Asking the interviewee to list strong skills and weaknesses is another common personality related question.