Introduction to DB Flashcards
1
Q
What are three ways data can vary?
A
Scope, format, and access
2
Q
Describe scope
A
The amount of data produced and collected
3
Q
Describe format
A
Data may be produced as numbers, text, image, audio, or video
4
Q
Describe access
A
Some data sources are private while others are public
5
Q
What is a database?
A
a collection of data in a structured format
6
Q
What is a DBMS?
A
database management systems are software for reading and writing into databases
7
Q
- What is a query?
A
- A request to change or retrieve something in the database
8
Q
- What is a query language?
A
- A special programming language for managing database operations
9
Q
- What is a database application?
A
- Special software that helps business users intact with databases.
10
Q
- What is an information management system?
A
- Software that manages corporate database for specific business function. Usually includes DBMS, UI, logs, and interfaces to other systems.
11
Q
- What is a database administrator?
A
- Responsible for securing the database systems against unauthorized users
12
Q
- What does a database designer do?
A
- Makes decisions about the format of data, response times, and support for rules that govern data
13
Q
- What does a database programmer do?
A
- Integrates database languages and other languages into a program that accesses databases.
14
Q
- Describe a database user
A
- Accesses the data in a database
15
Q
- What are 5 special requirements for large databases to manage?
A
- Performance, authorization, security, rules, and recovery
16
Q
- Describe performance
A
- Manages response time by structuring data and processing queries correctly
17
Q
- Describe authorization
A
- Authorize individual users to access specific data
18
Q
- Describe security
A
- Authorized users only access permissible data
19
Q
- Describe rules
A
- Ensure data is consistent with structural and business rules
20
Q
- Describe recovery
A
- Database system must be able to recover from a failure without loss of data
21
Q
- What is a transaction?
A
a group of queries that must be accepted or rejected as a whole
22
Q
What are the three protocols for processing transactions?
A
- Ensure transactions are processed completely
- Prevent conflicts between concurrent transactions
- ensure transactions are logged and never lost.
23
Q
- Why is it important to ensure transactions are processed completely or not at all?
A
- Incomplete transactions may lead to errors. In a batch of transactions if one fails, all should fail to avoid this.
24
Q
- Describe database architecture
A
- Describes the internal components of a database and how they interface with one another
25
Q
- Describe the job of a query processor
A
- Intreprets queries, modifies database, or retrieves data, and returns results
26
Q
- Describe the job of a storage manager
A
- Translates the a query into low level file management commands and uses indexes to quickly move data.
27
Q
- Describe the job of a transaction manager
A
- Ensures transactions are properly executed by preventing conflicts between concurrent transactions. Can restore database to consistent state after system failure.
28
Q
- Describe the job of a log
A
- Documents all inserts, updates, and deletes
29
Q
- Describe the job of a catalog( or data dictionary)
A
- The directory of tables, columns, indexes, and other database objects. AKA metadata
30
Q
- Describe a relational database
A
- Database organized like a spreadsheet. All data is stored in the same format. Supported by SQL
31
Q
- What is SQL?
A
- Structured query language used for reading, writing, and updating relational databases
32
Q
- How did NoSQL come about? What does it stand for?
A
- Big data in the 2000s confusing relational databases. Not-only sql
33
Q
- What does CRUD stand for?
A
- Create, retrieve, update, delete
34
Q
- What is an SQL statement?
A
- a database command (like a query) that inserts, selects, updates or deletes data
35
Q
- What are four SQL statements?
A
- INSERT, SELECT, UPDATE, DELETE
36
Q
- What does the SQL statement CREATE TABLE do?
A
- Creates a new table
37
Q
- What are the three data types of relational databases?
A
- Numbers, textual, and complex
38
Q
- What are some examples of the data types in relational databases?
A
- INT stores and integer value, DECIMAL stores a fractional number value, VARCHAR stores a textual value, DATE stores year, month, and day
39
Q
- What does VARCHAR(10) indicate?
A
- That the data type will be textual with a length of 10 letters
40
Q
- What are the three phases of large database design?
A
- analysis, logical design, and physical design
41
Q
- What is an entity?
A
- person, place, activity, or thing
42
Q
- What is an attribute?
A
- a descriptive property of an entity
43
Q
- What is a relationship?
A
- link between entities
44
Q
- Describe the logical design phase of relational database design
A
- Implements database requirements. In relational databases, this means converting entities, relationships, and attributes into tables, keys, and columns.
45
Q
- Describe the analysis phase of relational database design
A
- specifies database requirements without regard to a specific system
46
Q
- Describe the physical design phase of database design
A
- Adds indexes and specifies how tables are organized on storage media. Will effect query efficiency but not result.
47
Q
- Describe “data independence”
A
- The principle that physical design never affects query results
48
Q
- What is an API?
A
- application programming interface. I library of procedures that links a host programming language to a database.
49
Q
- SQL is usually implemented alongside what?
A
- A programming language
