Database Programming

Relevant information ensures that it is useful and applicable to the situation at hand, enabling better decision-making and problem-solving. It helps to avoid confusion, saves time, and allows individuals to focus on what is important.

The SAM database is the Security Accounts Manager database, used by Windows (and possibly other OS's) that manages user accounts and other things. It is implemented as a registry file that is locked for exclusive use while the OS is running. Even if its contents were discovered by some subterfuge, the keys are encrypted with a one-way hash, making it difficult to break. Also, some versions have a secondary key, making the encryption specific to that copy of the OS.

I would assume it was a relational database.. I also assume you mean the fingerprint database that is used by the police forces. as far as i am aware it is a relational database. I think because you could query either a name or a fingerprint reading and then get the information relating to it..

Example: If you were looking for the name to a set of fingerprints, you would enter the finger print into your query, and then you might get a name if it is in the database, and if you were looking for the fingerprints to a guy, you would enter a name and you might get the fingerprints for him if you have the right name and it is contained within the database.

Data can be stored in various ways, such as on physical storage devices like hard drives and flash drives, or in cloud storage services. Data can also be stored in databases, which are organized collections of data that can be easily accessed, managed, and updated. Additionally, data can be stored in memory, such as RAM, for faster access by computers and other devices.

The SQL command that can be used to retrieve all data from a table is the SELECT

Ex:

Let us say we have a table called employee_master which contains 3 columns emp_name, emp_number, date_of_joining you can retrieve all the data by using the below command

SELECT * FROM employee_master

or

SELECT emp_name, emp_number, date_of_joining FROM employee_master

Confidentiality of data refers to the practice of ensuring that sensitive information is accessible only to authorized individuals or systems. This includes protecting data from unauthorized access, disclosure, or alteration. Measures such as encryption, access controls, and data classification are typically used to maintain confidentiality.

A database is a structured collection of data organized for efficient retrieval and updating. A datastore is a repository for storing and managing data, which can include databases as well as other types of data storage systems such as key-value stores or document stores. Essentially, a database is a type of datastore, but not all datastores are databases.

Data manipulation is the process of changing or transforming data to make it more organized, accessible, or useful for analysis, reporting, or other purposes. This can involve tasks such as filtering, sorting, summarizing, merging, or transforming data in various ways using tools like spreadsheets, databases, or programming languages.

Data mining involves using techniques to find underlying structure and relationships in large amounts of data. The term data mining originated from database marketing industry. Data mining products tend to fall into five categories: neural networks, knowledge discovery, data visualization, fuzzy query analysis and case-based reasoning. Some uses of data mining include cross-selling (analyzing patterns of products frequently purchased together), response modeling (predicting which customers are likely to purchase based on purchase history), and segmentation and profiling (understanding customer segments by profiling archetypal customers). Common applications include mass mailing/telemarketing, medical diagnosis, credit card fraud and computer intrusion detection.

Web mining involves the analysis of Web server logs of a Web site. The Web server logs contain the entire collection of requests made by a potential or current customer through their browser and responses by the Web server. The information in the logs varies depending on the log file format and option selected on the Web server. Analysis of the Web logs can be insightful for managing the corporate e- business on a short-term basis; the real value of this knowledge is obtained through integration of this resource with other customer touchpoint information. Common applications include Web site usability, path to purchase, dynamic content marketing, user profiling through behavior analysis and product affinities.

To identify stored data in code, one typically uses variable names or keys within data structures like arrays, objects, or databases. By referencing these identifiers in the code, you can retrieve and manipulate the stored data as needed.

A primary key uniquely identifies each record in a table and ensures data integrity. A foreign key establishes a relationship between two tables, referencing the primary key of another table to enforce referential integrity.

Data storage on the internet is typically managed by data centers or cloud service providers. These entities are responsible for maintaining servers and infrastructure to store vast amounts of data securely and make it accessible to users worldwide. Organizations and individuals can store their data on these platforms by subscribing to their services.

A data model is a collection of concepts that can be used to describe the structure of a database.

Data models can be broadly distinguished into 3 main categories-

1)high-level or conceptual data models (based on entities & relationships)

It provides concepts that are close to the way many users perceive data.

2)lowlevel or physical data models

It provides concepts that describe the details of how data is stored in the computer.

These concepts are meant for computer specialist, not for typical end users.

3)representational or implementation data models (record-based,object-oriented)

It provide concepts that can be understood by end users. These hide some details of data storage but can be implemented on a computer system directly.

In simple terms, you can look at the database as being the files or tables with the data. A database system includes the other elements like queries, reports, forms, programs and other elements that manipulate and support the data in the database.

Data redundancy refers to repetitive data in the database. In a system with redundant data it is difficult to manage the relationships. Data redundancy is the result of poorly designed database. By implying proper constraints on the data it can be prevented.

File System vs Data base Management System :-

1. Files act locally where as DBMS saves directly in a database

2. Saves in temporary locations where as DBMS in well arranged and permanent data base locations

3. In File System., transactions are not possible where as various transactions like insert, delete, view, updating etc are possible in DBMS

4. Data will be accessed through single or various files where as in DBMS, tables (schema) is used to access data.

5. A "File manager" is used to store all relationships in directories in File Systems where as a data base manager (administrator) stores the relationship in form of structural tables

6. Last.... but not the least.... Data in data bases are more secure compared to data in files!!

One benefit of NIMS (National Incident Management System) is that it provides a standardized approach to incident management, enabling better coordination and communication between different agencies and organizations during emergencies.

"A data model is a collection of concepts that can be used to describe the structure of a database."

Data models can be broadly distinguished into 3 main categories-

1)high-level or conceptual data models (based on entities & relationships) - It provides concepts that are close to the way many users perceive data.

2)lowlevel or physical data models - It provides concepts that describe the

details of how data is stored in the computer.These concepts are meant for

computer specialist, not for typical end users.

3)representational or implementation data models (record-based,object-

0riented) - It provide concepts that can be understood by end users. These

hide some details of data storage but can be implemented on a computer

system directly.

Some of the disadvantages of dependency theory include oversimplification of complex economic relationships, neglect of internal factors contributing to underdevelopment, and criticism for offering limited solutions to address global inequality and poverty. Additionally, it has been criticized for its focus on historical colonial relationships at the expense of other critical factors influencing development.

1. Structured organization of data: Data is stored in tables with defined relationships.
2. Data integrity: Database systems enforce rules to maintain accuracy and consistency of data.
3. Query processing: Allows users to retrieve and manipulate data using SQL queries.
4. Concurrency control: Manages access to data to prevent conflicts in multi-user environments.

System data duplication, or denormalization, causes excess use of redundant storage, excess time processing queries, and possible inconsistency when de-normalized data is changed in one place but not the other. (Any one else have examples? Please enhance this answer. Thank you.)

Object Oriented Databases

Object oriented databases are also called Object Database Management Systems(ODBMS). Object databases store objects rather than data such as integers, strings or real numbers. Objects are used in object oriented languages such as Smalltalk, C++, Java, and others. Objects basically consist of the following:

Attributes - Attributes are data which defines the characteristics of an object. This data may be simple such as integers, strings, and real numbers or it may be a reference to a complex object.

Methods - Methods define the behavior of an object and are what was formally called procedures or functions.

Therefore objects contain both executable code and data. There are other characteristics of objects such as whether methods or data can be accessed from outside the object. We don't consider this here, to keep the definition simple and to apply it to what an object database is. One other term worth mentioning is classes. Classes are used in object oriented programming to define the data and methods the object will contain. The class is like a template to the object. The class does not itself contain data or methods but defines the data and methods contained in the object. The class is used to create (instantiate) the object. Classes may be used in object databases to recreate parts of the object that may not actually be stored in the database. Methods may not be stored in the database and may be recreated by using a class.

Comparison to Relational Databases

Relational databases store data in tables that are two dimensional. The tables have rows and columns. Relational database tables are "normalized" so data is not repeated more often than necessary. All table columns depend on a primary key (a unique value in the column) to identify the column. Once the specific column is identified, data from one or more rows associated with that column may be obtained or changed.

To put objects into relational databases, they must be described in terms of simple string, integer, or real number data. For instance in the case of an airplane. The wing may be placed in one table with rows and columns describing its dimensions and characteristics. The fusalage may be in another table, the propeller in another table, tires, and so on.

Breaking complex information out into simple data takes time and is labor intensive. Code must be written to accomplish this task.

Object Persistence

With traditional databases, data manipulated by the application is transient and data in the database is persisted (Stored on a permanent storage device). In object databases, the application can manipulate both transient and persisted data.

When to Use Object Databases

Object databases should be used when there is complex data and/or complex data relationships. This includes a many to many object relationship. Object databases should not be used when there would be few join tables and there are large volumes of simple transactional data.

Object databases work well with:

CAS Applications (CASE-computer aided software engineering, CAD-computer aided design, CAM-computer aided manufacture)

Multimedia Applications

Object projects that change over time.

Commerce

Object Database Advantages over RDBMS

Objects don't require assembly and disassembly saving coding time and execution time to assemble or disassemble objects.

Reduced paging

Easier navigation

Better concurrency control - A hierarchy of objects may be locked.

Data model is based on the real world.

Works well for distributed architectures.

Less code required when applications are object oriented.

Object Database Disadvantages compared to RDBMS

Lower efficiency when data is simple and relationships are simple.

Relational tables are simpler.

Late binding may slow access speed.

More user tools exist for RDBMS.

Standards for RDBMS are more stable.

Support for RDBMS is more certain and change is less likely to be required.

ODBMS Standards

Object Data Management Group

Object Database Standard ODM6.2.0

Object Query Language

OQL support of SQL92

How Data is Stored

Two basic methods are used to store objects by different database vendors.

Each object has a unique ID and is defined as a subclass of a base class, using inheritance to determine attributes.

Virtual memory mapping is used for object storage and management.

Data transfers are either done on a per object basis or on a per page (normally 4K) basis.

A database is made up of related Schemas and Tables. A single database can have multiple schemas and each schema can have multiple tables inside it. All of these can be related to one another using referential constraints like foreign keys.