Class Notes (1,100,000)
CA (620,000)
York (40,000)
ESSE (70)
Sohn (10)
Lecture 10

ESSE 3600 Lecture Notes - Lecture 10: Third Normal Form, Unique Key, Master Boot Record


Earth, Space Science and Engineering
Course Code
ESSE 3600

This preview shows half of the first page. to view the full 2 pages of the document.
Lecture 10 Practise Questions
These questions are taken straight from the chapter textbook review.
34. Spatial databases provide structures for storage and analysis of spatial data, and are a type of
database. A database is a collection of files, whereas a DBMS is a software package for storage,
manipulation, and retrieval of data from a database. Spatial data is comprised of objects in multi-
dimensional space, and storing spatial data in a standard database would require excessive amounts of
space. Spatial database management is necessary for managing spatial databases. It cam work with an
underlying DBMS, supports spatial data models, spatial operations, and spatial indexing and query
optimization over large spatial datasets. Some examples are Oracle Spatial and ESRI.
35. Hierarchical databases, network databases, and relational databases are types of classical database
structures, which are methods of organizing data and its relationships inside a database. The hierarchical
database model was created by Rockwell & IBM in the 60s/early 70s, and it is a tree-like structure. A
child belongs only to one parent, but a parent can have several children. 1:M parent child relationship.
The tree has a root & levels, and a node is a record whereas a branch is a relationship.
A network model was created in order to cope with a scenario with a complex set of relations. The basic
structure of a set, an owner and a series of members. A member can belong to more than one owner, so
M:N relations can be established.
A relational model was designed to accommodate a growing demand for queries, and a growing
demand for data and structural independence. Codd's model could not be implemented in 1970 due to
a lack of computational power. The relational database describes relations between entities by using
tables. Each row in the table is a tuple, a record, and each column is a field. Several types of relations
can be described using several tables. Each table has a unique identifier and the tables are not
36. Think of an MS Access table. There are rows full of entities and columns full of attributes. The key
field is one whose values identify each row. keys connect tables together. There are different types of
keys, primary keys(identifies all other attribute values in a given row).
37. An ER diagram is a database schema that consists of entities and relationships. For queries, we need
to work with one or more tables. If the query involves many tables, we gotta develop operators in order
to manipulate relations efficiently.
38. Please refer to Lab 6 for more information. The challenge in RDBMS is to design a schema that will
eliminate redundancies, inconsistencies, and anomalies. For this purpose, a set of normalization rules
could help. 1NF, 2NF, and 3NF. In 1NF normalization there are no repeating attributes, and all attributes
must have a single value. In 2NF normalization, 1NF and all non-key attributes have gotta depend on the
primary key. In 3NF normalization, 2NF and all non key attributes have no transitive dependence of
attribute on the primary key.
You're Reading a Preview

Unlock to view full version