Data Flashcards

1
Q

What are 4 of the most common database models?

A
  1. Flat-file
  2. Relational
  3. Hierarchical
  4. Object-oriented
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2
Q

What are the two major layers of a database application?

A
  1. Application layer
  2. Database management layer
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3
Q

What is a flat-file database?

Info stored?

Info separated

Limitation

A

Stores data in a plain text file.

Each line of the text holds one record.

Fields are separated by delimiters like spaces or comas.

Cannot contain multiple tables

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4
Q

What kinds of operations can be performed on a flat-file database? (4)

A
  1. Creating
  2. Deleting
  3. Updating
  4. Searching
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5
Q

What is a hierarchical Database?

A

One of the oldest database models organized in a tree structure like an organizational chart.

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6
Q

What is a relational database?

A

Contain tables that can be joined together in logical ways.

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7
Q

What does SQL do?

A

Includes queries to identify what data should be retrieved or how the data should be manipulated.

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8
Q

What does the selection operation do?

A

Takes rows from one table and creates a new table.

User specifies the table the rows are taken from and tests selection criterion. Selection is tested against each row and when a condition is met, that row is included in result table.

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9
Q

Select does what in SQL?

A

Identifies records being requested

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10
Q

(*) means what in SQL

A

Everything form the selected table

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11
Q

From in SQL

A

Identifies the table name

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12
Q

Where does what in SQL

A

Identifies the condition the query is requesting

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13
Q

What is Union Operation?

A

Combines distinct fields from multiple tables that have the same set of attributes and data types.

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14
Q

What is product operation?

A

Creates a result table that includes all the attributes from the two tables.

Each row of the second table is added to each row of the first table.

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15
Q

What is a join operation/What does it do?

A

Combines two tables but records are only appended when a matching criterion is met.

Resulting table includes a row with the attributes of both tables only when attributes from the first database table match related attributes from the second database table

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16
Q

What is an object oriented database?

What are the two components of OO

A

Stores complex data and relationships between data directly without using inner-table relations.

A collection of objects, each with two components
1. the data and
2. instructions (or software programs called methods)

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17
Q

Key-Value databases do what?

A

Store each item as an attribute name (key) together with its value

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18
Q

Graph stores do what?

A

Store information about networks of data such as social connections

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19
Q

Wide-column stores do what

A

Optimized for queries on large data sets and store columns of data together instead of rows.

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20
Q

Document-format databases do what?

A

Pairs each key with a complex data structure known as a document. Documents can contain many different key-value pairs

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21
Q

NoSQL does what?

A

Can accommodate a wide variety of data models including key value, document, columnar, and graph formats.

An alternative to traditional relational databases in which data is placed in tables that are carefully designed before the database is built.

22
Q

What kind of data are NoSQL databases especially useful for?

A

Large sets of distributed data.

23
Q

JSON is what?

A

A way of encoding information (a format) used in document databases

24
Q

What are two common uses of document databases?

A
  1. Content management
  2. Monitoring web and mobile applications
25
Q

Couchbase Server is an example of what kind of database?

A

Document

26
Q

CouchDB is an example of what kind of database?

A

Document

27
Q

MarkLogic is an example of what kind of database?

A

Document

28
Q

MongoDB is an example of what kind of database?

A

Document

29
Q

What are two common uses of graph databases?

A
  1. Recommendation engines
  2. Geospatial applications
30
Q

AllegroGraph is an example of what kind of database?

A

Graph

31
Q

Amazon Neptune is an example of what kind of database?

A

Graph

32
Q

ArangoDB is an example of what kind of database?

A

Graph

33
Q

IBM Db2 Graph is an example of what kind of database?

A

Graph

34
Q

Neo4j is an example of what kind of database?

A

Graph

35
Q

What are two common uses of key-value stores (DB)

A
  1. Storing clickstream data
  2. Application logs
36
Q

Aerospike is an example of what kind of database?

A

Key-Value

37
Q

Amazon DynamoDB is an example of what kind of database?

A

Key-Value

38
Q

Azure Table Storage is an example of what kind of database?

A

Key-Value

39
Q

Reidis is an example of what kind of database?

A

Key-Value

40
Q

Riak is an example of what kind of database?

A

Key-Value

41
Q

What are 2 common uses of wide-column stores (DB)?

A
  1. Internet Search
  2. Other large-Scale Web applications
42
Q

Accumulo is an example of what kind of database?

A

Wide-Column

43
Q

Cassandra is an example of what kind of database?

A

Wide-Column

44
Q

Google Cloud Bigtable is an example of what kind of database?

A

Wide-Column

45
Q

HBase is an example of what kind of database?

A

Wide-Column

46
Q

ScyllaDB is an example of what kind of database?

A

Wide-Column stores

47
Q

What are Cloud Databases?

A

Optimized to work in cloud environments.

48
Q

What are 3 practical benefits of Cloud Databases

A
  1. Ability to increase resources to accommodate for demands on the system
  2. To be highly available even in the case of local or regional outages
  3. To support SaaS cloud deployments
49
Q

What are Data Lakes?

A

A system of data stored in raw format. Usually a single store of all enterprise data as well as information derived from data during reporting, transactions, and other activities.

50
Q

What is a distributed Database?

A

Consists of data residing on different machines.