Homework C 15 Flashcards
XML
Extensible Markup Language
SQL
Structured Query Language
QBE
Query by Example
____ is information describing other information.
metadata
___ is a tagging scheme which has no standard tags.
XML
The first and thus fully enclosing tag in an XML document is called the ___.
Root element
The ___ rule says we should label data with tags consistently.
identification
The ___ rule says to enclose in a pair of tags all tagged data referring to the same entity.
affinity
The ___ rule says that when you have several instances of the same kind of data, enclose them in tags as well.
collection
An ___ is anything that can be identified by a fixed number of its characteristics or attributes.
entity
A(n) ____ database uses tables to organize information and describes relationships among the different kinds of data.
relational
In relational databases, a(n) ___ or field is a “column of a table.”
attribute
Attributes not only have a name but an associated ____ ____ (2 words) such as number, text or image.
data type
Another name for a database row is a record or a ____.
tuple
A(n) ___ is a collection of table definitions that give the name of the table, list of the attributes and their data types, and identifies the primary key.
schema
A(n) ___ is used to ensure that all entities in a database are unique.
Primary key
The ___ operation pulls rows of information that satisfy a particular test.
select
The ___ operation combines two tables which contain the same attributes.
union
The ___ operation pulls columns of information from a selected table.
project
The ___ operation combines two tables which contain different attributes except one and only combines those rows that have a common value is the shared attribute.
join
Using the Product operation on a table with 4 columns and 9 rows and a table with 7 columns and 6 rows will result in a table with ___ columns and ___ rows.
11, 54
The ___ database is designed by the database administrator so that the data is fast to access from the disk drive.
physical
The ___ database shows users the view of the information that they need and want.
logical
When we want to ask a question of the database, we make a ____ using the six database operations. The result is a new table.
query
Access and most modern database systems use a language called ___ as the standard database language.
SQL
IBM created a technique in the 1970s called ___ which makes creating queries much easier.
QBE
