Presentation is loading. Please wait.

Presentation is loading. Please wait.

Data Bits Many to Many Subkeys JoinsQueries Attributes $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 Final DataBit.

Similar presentations


Presentation on theme: "Data Bits Many to Many Subkeys JoinsQueries Attributes $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 Final DataBit."— Presentation transcript:

1

2

3 Data Bits Many to Many Subkeys JoinsQueries Attributes $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 Final DataBit

4

5 $100 Answer from Many-to- Many This represents a specific modeling situation that you might encounter frequently in database design..

6 $100 Question from Many-to- Many What is a design pattern?

7 $200 Answer from Many-to- Many This class contains attributes which are the properties of an association.

8 $200 Question from Many-to- Many What is an association class?

9 $300 Answer from Many-to- Many This association has a maximum multiplicity of "*" on both sides.

10 $300 Question from Many-to- Many What is a many-to-many association?

11 $400 Answer from Many-to- Many This attribute can be computed from data stored elsewhere in the database; it is shown in UML but not in the relation scheme.

12 $400 Question from Many-to- Many What is a derived attribute?

13 $500 Answer from Many-to- Many This table is created to hold the linking attributes (FKs) from both sides of a many-to-many association, whether or not there is an association class.

14 $500 Question from Many-to- Many What is a junction table?

15 $100 Answer from Subkeys This is the formal definition of the super key property; if I know the value of set "X" of attributes in a relation, I can uniquely determine the value of set "Y" (as well as X).

16 $100 Question from Subkeys What is a functional dependency?

17 $200 Answer from Subkeys This set of attributes is a super key for some, but not all, of the attributes in a relation.

18 $200 Question from Subkeys What is a subkey?

19 $300 Answer from Subkeys This decomposition of a relation scheme eliminates a subkey and lets us recreate the original scheme’s information with the join in a query.

20 $300 Question from Subkeys What is lossless join decomposition?

21 $400 Answer from Subkeys Following this set of rules insures that a database is well designed.

22 $400 Question from Subkeys What is normalization?

23 $500 Answer from Subkeys A database with no subkey in any relation (with rare exceptions) is said to be in this form.

24 $500 Question from Subkeys What is third normal form?

25 $100 Answer from Joins Join of two tables with the intersection of their schemes used as join attributes.

26 $100 Question from Joins What is a natural join?

27 $200 Answer from Joins Join of two tables with join attributes specified by the programmer.

28 $200 Question from Joins What is an inner join?

29 $300 Answer from Joins Join of two tables that retains unmatched join attributes from one or both sides.

30 $300 Question from Joins What is an outer join?

31 $400 Answer from Joins Paste of every pair of tuples from each relation, disregarding join attributes. Also know as a Cartesian product.

32 $400 Question from Joins What is a cross join?

33 $500 Answer from Joins An alternate, short name for a table in the FROM clause of a SELECT statement.

34 $500 Question from Joins What is an alias?

35 $100 Answer from Queries This language is used to build and manipulate relational databases. It is declarative, rather than procedural.

36 $100 Question from Queries What is the Structured Query Language (SQL)?

37 $200 Answer from Queries Statements to create and modify tables and other database objects.

38 $200 Question from Queries What is Data Definition Language (DDL)?

39 $300 Answer from Queries Statements to work with data in a table.

40 $300 Question from Queries What is Data Manipulation Language (DML)?

41 $400 Answer from Queries Clause used when you combine single columns with an aggregate function.

42 $400 Question from Queries What is a Group By Clause?

43 $500 Answer from Queries Function that operates on a group of rows, for example, SUM.

44 $500 Question from Queries What is an Aggregate Function?

45 $100 Answer from Attribute Attribute This is considered a class within a class.

46 $100 Question from Attribute Attribute What is a weak entity?

47 $200 Answer from Attribute Attribute There are many distinct values entered for this in the same column of the table.

48 $200 Question from Attribute Attribute What is a multi-valued attribute?

49 $300 Answer from Attribute Attribute This causes a large number of null values in a table row.

50 $300 Question from Attribute Attribute What is a repeated attribute?

51 $400 Answer from Attribute Attribute [0..*]

52 $400 Question from Attribute Attribute What is the UML notation to show a repeating or multi-valued attribute?

53 $500 Answer from Attribute Attribute You would only do this when the repeated attribute has several attributes of its own You would only do this when the repeated attribute has several attributes of its own.

54 $500 Question from Attribute Attribute What is show the repeating attribute in its own class?

55 Final DataBit Keys An outside agency such as a standards body or a government agency has developed this so that we can use it as if it were a descriptive attribute.

56 Final DataBit What is an external (surrogate) key?


Download ppt "Data Bits Many to Many Subkeys JoinsQueries Attributes $100 $200 $300 $400 $500 $100 $200 $300 $400 $500 Final DataBit."

Similar presentations


Ads by Google