COMFUN MIDTERMS

Database

Is an organized collection of Information. The information is stored in a structured manner for easier access.

Creation

This step involves defining what information the database will store, where it will be hosted, and how it will be accessed by clients.

Import/Input

Once the database has been created, it must be populated with data records.

Storage (data persistence)

While an application processes variables and other temporary data internally, this information is lost when the application is terminated. A database represents a way for an application to store data persistently and securely.

Queries

This is used to extract information efficiently.

Reports

This is a means of formatting summarizing the records returned by a query so that the information is easy to read and interpret.

Excel

Enables you to store your information in sheets, which are broadly analogous to tables, with rows and columns of data.

Comma Separated Values (CSV)

This type of file uses commas to identify the end of a column and a line feed for each row.

Flat File System

This might be useful for tasks such as simple order or sales databases used by a single person or small workgroup.

Relational Database

This is a highly structured type of database, Information is organized in tables (Known as relations).

Structured Query Language (SQL)

This is typically used by Relational Database Management Systems (RDBMS) to maintain and query data in the database,

Microsoft SQL Server, Oracle Database, MySQL, Microsoft Office Access

Examples of Relational Database Management Systems.

Garbage in, Garbage out (GIGO)

One of the functions of an RDBMS is to address the concept of this.

Primary Key

This is an example of a constraint. The value entered or changed in this term's field in any given record must not be the same as any other existing record.

Unstructured Data

This provides no rigid formatting of the data. Images and text files, Word documents and PowerPoint presentations are examples of this.

Semi-Structured Data

Strictly speaking, the data lacks the structure of formal database architecture. But in addition to the raw unstructured data, there is associated information called metadata that helps identify the data

Document Database

This is an example of a semi-structured database. Rather than define tables and fields, the database grows by adding documents to it.

XML (Extensible Markup Language)

An example of a markup language that documents would very commonly use to provide structure.

Key/Value Pair Database

Is a means of storing the properties of objects without predetermining the fields used to define an object.

Non-Relational

Document Databases and Key/Value pair databases are _________ because there are no formal structures to link the different data objects and files.

Database Intefaces

These are the processes used to add/update information to and extract (or view) information from the database.

Data Definition Language (DDL)

These type of commands refer to SQL commands that add to or modify the structure of the database. Some examples of data definition commands are:

Create

This command can be used to add a new database on the DBMS server or add a new table within an existing database.

Alter Table

This allows you to add, remove (drop), and modify table columns (fields), change a primary key and/or foreign key, and configure other constraints.

Drop

This command is used to delete a table or database.

Create Index

Specifying that a column (or combination of columns) is indexed speeds up queries on that column. The tradeoff is that updates are slowed down slightly, or quite a lot if the column is not suitable for indexing.

Data Manipulation Language (DML)

These type of commands allow you to insert or update records and extract information from records or viewing.

Insert Into

This command adds a new row in a table in the database.

Update

This command changes the value of one or more table columns.

Delete From

This command deletes records from the table.

Select

This command enables you to define a query to retrieve data from a database.

Database Access Methods

These are the processes by which a user might run SQL commands on the database server or update or extract information using a form or application that encapsulates the SQL commands as graphical controls or tools

One-tier or standalone application architecture

If the application front-end and processing logic and database engine are all hosted on the same computer, the application architecture can be described as this.

Two-tier client-server application architecture

This separates the database engine, or back-end or data layer, from the presentation layer and the application layer, or business logic

Three-tier application architecture

The presentation and application layers are also split. The presentation layer provides the client front-end and user interface and runs on the client machine. The application layer runs on a server or server cluster that the client connects to.

N tier application architecture

This can be used to mean either a two-tier or three-tier application, but another use is an application with a more complex architecture still. For example, the application may use separate access control or monitoring services.

Universal Serial Bus (USB)

This has become the standard means of connecting peripheral devices to a computer.

Type-A

For connection to the host. The connector and port are shaped like flat rectangles.

Type B

For connection to a device. The connector and port are square, with a beveled top.

Type B Mini

A smaller connector for connection to a device. This type of connector was seen on early digital cameras but is no longer widely used.

Type B Micro

An updated connector for smaller devices, such as smartphones and tablets. The micro connector is distinctively flatter than the older mini type connector.

Type C

A new reversible connector type (can be inserted either way up).

12 Mbps

The data rate for USB 1.1

480 Mbps

The data rate for USB 2.0

USB 3.0

This introduces a SuperSpeed mode. SuperSpeed improves the bus bandwidth tenfold (to 5 Gbps or 5000 Mbps) and makes the link full duplex, so a device can send and receive at up to 5 Gbps simultaneously.

Firewire

This bus was based on the IEEE 1394 standard and the Small Computer System Interface (SCSI) communications protocol.

VGA (Video Graphics Array)

IBM created this as a standard for the resolution and color depth of computer displays. This specifies a resolution of 640x480 with 16 colors (4-bit color) at 60 Hz.

DisplayPort

This was developed by VESA, the organization largely representing PC graphics adapter and display technology companies. It is a royalty-free standard intended to "complement" HDMI.

High-Definition Multimedia Interface (HDMI)

This is the most widely used graphic device interface. It is ubiquitous on consumer electronics, such as televisions and Blu-Ray players, as well as computer equipment.

HDMI cabling

This is specified to different HDMI versions, the latest being 2.1. Newer versions support higher bandwidths and consequently better resolutions (4K UHD for instance).

Thunderbolt (TB)

This interface was developed by Intel and is primarily used on Apple workstations and laptops.

Digital Visual Interface (DVI)

This is a high-quality digital interface designed for flat-panel display equipment.

Human Interface Devices (HID)

These are peripherals that enable the user to enter data and select commands.

Keyboard

This is the longest serving type of input device.

Mouse

This is the main type of input device for graphical software. It is an example of a class of input devices described as pointing devices.

Stylus Pen

These can be used with a compatible touch display or graphics tablet.

Radio Frequency ID (RFID)

Is a means of tagging and tracking objects using specially-encoded tags.

Near Field Communications (NFC)

This is a peer-to-peer version of RFID;

Network Interface Card (NIC)

Most computers have these already installed as part of the motherboard chipset.

Microphone

This allows for audio input and recording.

Headphones/Speakers

Devices that allows for audio output.

Headset

A device with both microphone and headphones.

Audio in (light blue)

Is a lowlevel (1V) stereo signal as supplied by most tape decks, video players, tuners, CD players, and so on.

Microphone input (pink)

This is generally a mono analog input.

Audio out (lime)

Is a lowlevel (1V) analog stereo signal suitable for feeding into an amplified speakers or headphones.

Audio out (black)

Signal for rear speakers in a surround sound system

Audio out (orange)

Signal for the subwoofer in a surround sound system.

Webcams

Record video images using a digital sensor and usually feature a microphone to record audio. They range in quality from models with low resolution and frame rates (25 fps [frames per second]) to models capable of High-Definition resolution at 60 fps.

System Memory

This is the main storage area for programs and data when the computer is running. This is is necessary because it is much faster than accessing data in a mass storage system, such as a hard disk..

Random Access Memory (RAM)

A type of volatile memory.

Dynamic RAM (DRAM)

This stores each data bit as an electrical charge within a single bit cell. The electrical charge gradually dissipates, causing the memory cell to lose its information. In order to preserve the information, dynamic memory has to be refreshed periodically by accessing each cell at regular intervals.

Synchronous DRAM (SDRAM)

Is synchronized to the system bus. It has a 64-bit data bus, meaning that in each clock cycle, 64 bits of information can be delivered to the CPU.

Hard Disk Drives (HDD)

These are one of the most widely used type of mass storage device. Data on this is encoded magnetically on specially coated glass or plastic platters accessed by drive heads. The platters are spun at very high speeds, giving rise to the term "spinning disk" drive.

Solid State Drives (SSD)

These are designed to replicate or supplement the function of the hard drive. This storage uses a type of non-volatile memory technology called flash memory.

Compact Discs (CDs), Digital Video Discs or Digital Versatile Discs (DVDs), and Blu-ray Discs (BDs)

These are storage formats for consumer multimedia, such as music and video. They are referred to as "optical" drives because a laser is used to read data from the discs.

Liquid Crystal Display (LCD)

Each picture element (pixel) in a this display type comprises cells (or subpixels) with filters to generate the three primary colors (red, green, and blue) and transistors to vary the intensity of each cell, so creating the gamut (range of colors) that the display can generate.

Touchscreen

Are used on handheld portable devices, but they are also useful in industrial environments or for public terminals, such as kiosks, where mice or keyboards could be damaged, stolen, or vandalized.

Printer Technology

This is the mechanism used to make images on the paper.

Inkjets

These type of printers are often used for good quality color output. These are typically cheap to buy but expensive to run, with high-cost consumables such as ink cartridges and high-grade paper. They are slower and noisier than laser printers.

Scanner

Is an imaging device, designed to create a digital file from a page of print, photo, or another object.

Flatbed Scanner

This works rather like a photocopier. The object to be scanned is placed on a glass faceplate and the cover closed to prevent ambient light affecting the image.

Multi-function Devices (MFD)

These may use a sheet-fed scanner rather than a flatbed one

Partitioning

The act of doing this to a hard disk is the act of dividing it into logically separate storage areas. This may be done to improve the performance of the disk, to install multiple operating systems, or to provide a logical separation of different data areas.

FAT (File Allocation Table)

This was used for older versions of Windows and is preserved under Windows for compatibility.

NTFS (New Technology File System)

As a 64-bit addressing scheme, this allows much larger partitions (up to 2 TB) than FAT.

Compression

The file system can automatically reduce the amount of disk space taken up by a file. The file system applies a non-lossy algorithm to the file to find ways to store the data in it more efficiently without discarding any information.

Encryption

The file system can automatically encrypt data in a file when it is saved.

Permissions

The file system maintains an Access Control List (ACL) for each file or folder object. The ACL records which user accounts are allowed to read, write, or control the object

Journaling

The file system tracks changes or intended changes in a log. This means that if there is a sudden power cut and a particular write operation was interrupted, this may be used to recover the data or at least restore the file system to good working order (consistent state).

File Explorer

This provides a visual means of navigating the file system. In the main pane, you can double-click a folder to open it. You can use the Navigation pane to expand and collapse objects or the Breadcrumb on the address bar and Back and Forward buttons on the toolbar.

Quick Access

Contains shortcuts to folders that are most useful. These can be modified by dragging and dropping.

OneDrive

If you sign into the computer with a Microsoft account, this shows the files and folders saved to your cloud storage service on the Internet. As you can see from the screenshot, other cloud service providers may add links here too.

User account

The folders belonging to your account profile.

This PC

Access to user-generated files in the user's profile plus the hard drives and removable storage drives available to the PC.

Libraries

These can be used to create views of folders and files stored in different locations and on different disks.

Network

Contains computers, shared folders, and shared printers available over the network.

Control Panel

Options for configuring legacy Windows features

Recycle Bin

Provides an option for recovering files and folders that have been recently deleted.

txt

A text-only file with no "binary" file information linking the file to a particular software application. Any application can open a text file, but this file type cannot store any information about formatting or layout.

rtf

This is an early "generic" file format for sharing documents between different word processing applications. It is capable of storing basic formatting information, such as font and paragraph formatting, and layout features, such as tables.