Glossary of Common Database Terms
- ACID. Atomicity: Each database transaction must follow an all-or-nothing rule, meaning that if any part of the...
- Attribute. A database attribute is a characteristic of a database entity. An attribute is a column in a database table,...
- Authentication. Databases use authentication to ensure that only authorized users can access the...
Full Answer
What are the key terms associated with a database?
- A table or file refers to a list of data.
- A database is either a single table or a collection of related tables. ...
- A column or field defines the data that a table can hold. ...
- A row or record represents a single instance of whatever the table keeps track of. ...
- A key is the field used to relate tables in a database. ...
Is database one or two words?
There was a huge debate at the time if database was two words or one word. I put my foot down that it was one word. Unfortunately, the dictionary didn't back up my position. I gave up, the RFP went out with over 20 references to "data base".
What is a database term?
A database is an organized collection of data, generally stored and accessed electronically from a computer system. Where databases are more complex they are often developed using formal design and modeling techniques.
What is a relation in database terminology?
- The selection, or restriction, operation retrieves tuples from a relation, limiting the results to only those that meet a specific criterion, i.e. ...
- The projection operation extracts only the specified attributes from a tuple or set of tuples.
- The join operation defined for relational databases is often referred to as a natural join. ...
What are the terminologies of database management system?
A database management system is a software system which facilitates the organization of housed data into a particular database architecture, be it relational (Relational Database Management System, or RDBMS), document store, key-value store, column-oriented, graph, or other.
What are the 4 types of database?
Four types of database management systemshierarchical database systems.network database systems.object-oriented database systems.
What are the 5 components of a database system?
The five major components of a database are hardware, software, data, procedure, and database access language.
What is terminology in SQL?
In the relational model of data, all data is perceived as existing in tables. Db2® for i objects are created and maintained as system objects. The following table shows the relationship between system terms and SQL relational database terms.
What are the 5 types of database?
What are the types of databases?Relational databases. Relational databases have been around since the 1970s. ... NoSQL databases. ... Cloud databases. ... Columnar databases. ... Wide column databases. ... Object-oriented databases. ... Key-value databases. ... Hierarchical databases.More items...•
What are the 5 data models?
Types of database modelsHierarchical database model.Relational model.Network model.Object-oriented database model.Entity-relationship model.Document model.Entity-attribute-value model.Star schema.More items...
What are main components of database?
Components of a database management systemStorage engine.Query language.Query processor.Optimization engine.Metadata catalog.Log manager.Reporting and monitoring tools.Data utilities.
What are different types of database?
Types of databasesCentralised database.Distributed database.Personal database.End-user database.Commercial database.NoSQL database.Operational database.Relational database.More items...•
Why is SQL used?
SQL is used to communicate with a database. According to ANSI (American National Standards Institute), it is the standard language for relational database management systems. SQL statements are used to perform tasks such as update data on a database, or retrieve data from a database.
What is DBMS and its types?
There are three main types of DBMS data models: relational, network, and hierarchical. Relational data model: Data is organized as logically independent tables. Network data model: All entities are organized in graphical representations. Hierarchical data model: Data is organized into a tree-like structure.
What is the base model?
The BASE model has been developed as an alternative to the ACID model to serve the needs of noSQL databases in which the data is not structured in the same way required by relational databases. Its primary tenets are:
What is a database query?
A database query is usually written in SQL and can be either a select query or an action query. A select query requests data from a database; an action query changes, updates, or adds data. Some databases provide drag-and-drop forms that hide the semantics of the query, helping people to request information without having to write valid SQL.
What is consistency in database?
Consistency: Each database transaction must follow all the database's defined rules; any transaction that would violate these rules is not allowed. Isolation: Each database transaction will occur independently of any other transaction. For example, if multiple transactions are submitted concurrently, the database will prevent any interference ...
What are the rules of ACID?
The ACID model of database design enforces data integrity through: 1 Atomicity: Each database transaction must follow an all-or-nothing rule, meaning that if any part of the transaction fails, the entire transaction fails. 2 Consistency: Each database transaction must follow all the database's defined rules; any transaction that would violate these rules is not allowed. 3 Isolation: Each database transaction will occur independently of any other transaction. For example, if multiple transactions are submitted concurrently, the database will prevent any interference between them. 4 Durability: Each database transaction will permanently exist despite any database failure, through backups or other means.
What is the most commonly used language to access data from a database?
Structured Query Language, or SQL, is the most commonly used language to access data from a database. SQL branches into two types of syntax. The Data Manipulation Language contains the subset of SQL commands used most frequently and includes SELECT, INSERT, UPDATE and DELETE.
Why do we use authentication in databases?
Authentication. Databases use authentication to ensure that only authorized users can access the database or certain aspects of the database. For example, administrators might be authorized to insert or edit data, while regular employees might be able to only view data.
What happens when multiple transactions are submitted concurrently?
For example, if multiple transactions are submitted concurrently, the database will prevent any interference between them. Durability: Each database transaction will permanently exist despite any database failure, through backups or other means.
What is database in 2021?
April 8, 2021. A database is a structure that organizes and stores data electronically. The data is stored using a database management system (DBMS) such as Microsoft Access, MySQL or Microsoft SQL Server. Data is organized into rows, columns, and tables, so that it can be easily accessed, managed and updated.
What is table data?
A table is a set of data represented by columns and rows. A column is referred to as a field and a row is a combination of column values and is referred to as a record. Tables contain a unique set of characteristics and they store data of the same type in each row.
What is data field?
A data field which is one piece of information you track in your database. Each data field in the table can define the characteristics of its data as a string value, numeric value, date and/or time values.
How many primary keys are there in a table?
The Primary key should always be the first field in each table, followed by any foreign key (s). There is only one Primary Key per table. Primary keys should never be actual data – not even something unique like a Social Security number or Student ID.
Can a foreign key be null?
Each value is unique to the table and cannot be null. Foreign Key: A field in a related table pointing back to the Primary Key in another table. For auto-numbered fields it is defined as a number value. The Primary key should always be the first field in each table, followed by any foreign key (s).
What is a DDL query?
Terms such as ''create'', ''alter'', and ''drop'' are considered DDL, or database definition language, because they can either create, modify, or remove entire tables within a database. A query containing the word ''select'' that simply displays data to the user is commonly referred to as a select statement.
What is database in computer science?
Understanding databases has to start at the surface. A database is simply a structured collection of data. The data is typically ordered into tables similar to a table you may see in Microsoft Excel - only much larger! Each table has columns and rows and a piece of data housed in a specific column. A row is referred to as a record. Each piece of data has a data type, such as an integer, date, or time, that helps the computer ''expect'' and define what type of data is allowed in that column. The data doesn't just sit there in cyberspace somewhere, though; the tables and data housed in a database can have a number of different uses and relationships.
What is SQL in SQL?
SQL, or structured query language, is the programming language that's standard for querying a database.
What is a junction table?
A junction table holds information from both tables and has a primary key that is a combination of the foreign keys from both tables that it is relating to.
What is the primary key in a database?
A table has what's called a primary key that helps relate it to other tables. A primary key is usually a critical and identifying piece of data .
How many types of relationships are there in a database?
Tables within a database can have three different types of relationships: one-to-one, one-to-many, and many-to-many. Understanding each of these relationships can really help a database to feel less foreign because it maps tables to one another and shows how the data is all interconnected.
Why is the column containing the name the primary key?
For instance, in a table of customer names, addresses, and phone numbers, the column containing the name would most likely be the primary key because it holds the most significance. A foreign key works in conjunction with a primary key. A foreign key tells two tables that they are housing similar columns.
What are some examples of RDBMS?
Oracle, MySql, SQL Server are some of the example of RDBMS database. Non-Relational Database: A non-relational database is a database that does not incorporate the table/key model that relational database management systems promote. MangoDB and NoSQL are some of the examples of non-relational database.
What is a row in a database called?
A row is also called a record or a tuple. View: A view is the result set of a stored query on the data which the database users can query just as they would in a database. Synonym : A database object which provide an alternative name for an object.
What is a hot backup?
Hot Backup: A Hot backup is the backing up process which is done while the database is online. This is also called online backups. Hot backup is performed on databases that are processing transactions 24 by 7.
What is the difference between a table and a database?
Table: A table is a collection of related data held in a structured format within a database that consist of columns and rows.
What is a function in SQL?
Function: A Function is a routine that accepts parameter (s), performs an action, such as a complex calculation, and return the result of that action as a value. The return value can either be a single scalar value or a result set.
Database Designer
She will be in charge of deciding how to organize the data into tables and how to set up the relations between these tables. This step is crucial. If the database design is not perfect from the beginning, your system will be difficult to work with and wouldn’t facilitate your business needs; you will have to start over again.
Relational Schema
Another form of representation of a database is the relational schema. This is an existing idea of how the database must be organized. It is useful when you are certain of the structure and organization of the database you would like to create.
Database Management
You will often hear the term database management. It comprises all these steps a business undertakes to design, create, and manipulate its databases successfully.