Data Warehouse :: Data Warehousing Job Interview Questions and Answers

Data Warehousing Interview Questions and Answers will guide now that Data warehouse is a repository of an organizations electronically stored data. Data warehouses are especially designed to facilitate reporting and analysis about the data of any organization. So learn Data Warehousing concepts by Data Warehousing Interview Questions and Answers and get preparation of Data Warehousing Jobs Interview.

1 ► What is Meta data?
2 ► Briefly state different between data ware house & data mart?
3 ► What is galaxy schema?
4 ► Suppose you are filtering the rows using a filter transformation only the rows meet the condition pass to the target. Tell me where the rows will go that does not meet the condition.
5 ► After we create a SCD table, can we use that particular Dimension as a dimension table for Star Schema?
6 ► What is Core Dimension?
7 ► How much data hold in one universe.
8 ► Can any one explain about Core Dimension, Balanced Dimension, and Dirty Dimension?
9 ► Can any one explain the Hierarchies level Data warehousing.
10 ► What is data cleaning? How can we do that?
11 ► What is dimension modeling?
12 ► Where the cache files stored?
13 ► How can you import tables from a database?
14 ► What is drilling across?
15 ► How Many different schemas or DW Models can be used in Siebel Analytics. I know Only STAR and SNOW FLAKE and any other model that can be used?
16 ► What is an error log table in Informatica occurs and how to maintain it in mapping?
17 ► What is loop in Data warehousing?
18 ► How many clustered indexes can u create for a table in DWH? In case of truncate and delete command what happens to table, which has unique id.
19 ► What is hybrid slowly changing dimension?
20 ► Can a dimension table contain numeric values?
21 ► How do you create Surrogate Key using Ab Initio?
22 ► What is the difference between star and snowflake schemas?
23 ► What is a CUBE in data warehousing concept?
24 ► What is the difference between Snowflake and Star Schema? What are situations where Snowflake Schema is better than Star Schema when the opposite is true?
25 ► What is ER Diagram?
26 ► What is degenerate dimension table?
27 ► What is VLDB?
28 ► What is Dimensional Modeling?
29 ► What are the various ETL tools in the Market?
30 ► What are the possible data marts in Retail sales?
31 ► What is meant by metadata in context of a Data warehouse and how it is important?
32 ► What is a linked cube?
33 ► What is surrogate key? Where we use it? Explain with examples.
34 ► What are the data types present in BO? What happens if we implement view in the designer n report?
35 ► What are data validation strategies for data mart validation after loading process?
36 ► What is Data warehousing Hierarchy?
37 ► What is BUS Schema?
38 ► What are the methodologies of Data Warehousing?
39 ► What is conformed fact?
40 ► What is Difference between E-R Modeling and Dimensional Modeling?
41 ► Why fact table is in normal form?
42 ► What is junk dimension? What is the difference between junk dimension and degenerated dimension?
43 ► What is the main difference between Inmon and Kimball philosophies of data warehousing?
44 ► What is the difference between view and materialized view?
45 ► What is the advantages data mining over traditional approaches?
46 ► What are the steps to build the data warehouse?
47 ► What is the data type of the surrogate key?
48 ► What is a source qualifier?
49 ► What do you mean by static and local variable?
50 ► What are the different types of data warehousing?
51 ► What are Fact, Dimension, and Measure?
52 ► What is the data type of the surrogate key?
53 ► What are Data Marts?
54 ► What are the differences between star and snowflake schema?
55 ► What is a cube in data warehousing concept?
56 ► What are the difference between Snow flake and Star Schema? What are situations where Snow flake Schema is better than Star Schema to use and when the opposite is true?
57 ► What is Dimensional Modelling?
58 ► What is Log Switch?
59 ► What is On-line Redo Log?
60 ► Which parameter specified in the DEFAULT STORAGE clause of CREATE TABLESPACE cannot be altered after creating the table space?
61 ► What are the steps involved in Database Startup?
62 ► What are the steps involved in Instance Recovery?
63 ► Can Full Backup be performed when the database is open?
64 ► What are the different modes of mounting a Database with the Parallel Server?
65 ► What are the advantages of operating a database in ARCHIVELOG mode over operating it in NO ARCHIVELOG mode?
66 ► What are the steps involved in Database Shutdown?
67 ► What is Archived Redo Log?
68 ► What is Restricted Mode of Instance Startup?
69 ► What is Partial Backup?
70 ► What is Mirrored on-line Redo Log?
71 ► What is a full backup?
72 ► Can a View based on another View?
73 ► Can a Table space hold objects from different Schemes?
74 ► Can objects of the same Schema reside in different table spaces?
75 ► What is the use of Control File?
76 ► Do you View contain Data?
77 ► What are the Referential actions supported by FOREIGN KEY integrity constraint?
78 ► What are the types of Synonyms?
79 ► What is a Redo Log?
80 ► What is an Index Segment?
81 ► Explain the relationship among Database, Table space and Data file?
82 ► What are the different types of Segments?
83 ► What are Clusters?
84 ► What is an Integrity Constrains?
85 ► What is an Index?
86 ► What is an Extent?
87 ► What is a View?
88 ► What is Table?
89 ► What is schema?
90 ► Describe Referential Integrity?
91 ► What is a Hash Cluster?
92 ► What is a Private Synonyms?
93 ► What is Database Link?
94 ► What is a Table space?
95 ► What is Rollback Segment?
96 ► What are the Characteristics of Data Files?
97 ► How do you define Data Block size?
98 ► What does a Control file Contain?
99 ► What is the effect of setting the value "CHOOSE" for OPTIMIZER_GOAL, parameter of the ALTER SESSION Command?
100 ► What is the function of Optimizer?
101 ► What is Execution Plan?
102 ► What are the different approaches used by Optimizer in choosing an execution plan?
103 ► What is the difference between OLAP and OLTP?
104 ► What is the difference between aggregate table and materialized view?
105 ► "A dimension table is wide but the fact table is deep," Explain the statement in your own words.
106 ► What is a data profile?
107 ► Explain the advantages of RAID 1, 1/0, and 5. what type of RAID setup would you put your TX logs.
108 ► What is the difference between mapping parameter & mapping variable in data warehousing?
109 ► What is the difference between metadata and data dictionary?
110 ► What is Virtual Data Warehousing?
111 ► Which technology should be used for interactive data querying across multiple dimensions for a decision making for a DW?
112 ► What is the difference between dependent data warehouse and independent data warehouse?
113 ► What is the main difference between star and snowflake star schema? Which one is better and why?
114 ► What is critical column?
115 ► How can you implement many relations in star schema model?
116 ► Where the Data cube technology is used?
117 ► Can you pass sql queries in filter transformation?
118 ► After the complete generation of a report who will test the report and who will analyze it?
119 ► After the generation of a report to whom we have to deploy or what we do after the completion of a report?
120 ► What is "method/1"?
121 ► What are data modeling and data mining? Where it will be used?
122 ► What is data analysis? Where it will be used?
123 ► What is data warehouse architecture?
124 ► What is Informatica Architecture?
125 ► What is unit testing?
126 ► What is type 2 version dimension?
127 ► For faster process, what we will do with the Universe?
128 ► I have two Universes created by two difference database can we join them in Designer & Report level? How
129 ► What is difference between drill & scope of analysis?
130 ► What is a real-time data warehouse? How is it different from near to real-time data warehouse?
131 ► How can we run the graph? What is the procedure for that? How can we schedule the graph in UNIX?