Types of Databases

In this course, we will study different types of databases - distributed, deductive, real-time, centralized, parallel and decentralized databases.

What are the types of databases?

There are various kinds of databases depending upon the usage requirements. These are the types of databases available in the market:

Types of Databases

Deductive database

This is a database system that can make judgments about its data based on a set of well-defined rules and facts.
This type of database was developed to combine logic programming with relational DBMS.

Why the deductive database?

Declarative: clear understanding of what a database represents.
Expressiveness: there are queries that cannot be formulated using relational algebra can be easily expressed by datalog rules.

Real-time database

☆ These are the databases used in real-time applications.
☆ Real-time systems include acid properties and time constraints.
☆ There are two types of real-time applications- soft real-time and hard real-time.
☆ The soft real-time systems if we are not able to meet the time constraints then no serious damage occurs but in case of a hard real-time system the damage is serious and causes various problems.

Why real-time databases?

☆ Boosts up the productivitybr
☆ Saves money
☆ Accuracy is increased
☆ Saves time
☆ Decision making and crisis management is improved

Centralized database

In these databases, the information is stored at a centralized location and it can be accessed by users from a different location.

The database contains various application procedures that help the users in accessing the data even from a remote location.

There are various kinds of authentication procedures that are applied for verification and validation purposes, likewise, a registration id number is provided by the application procedures which helps in keeping the track and record of data usage. It is handled by the local area office.

In these databases, the chances of failure are more as the system is centralized.
Security issues are more

Why a centralized database?

☆ Easier to set up
☆ Affordable to maintain
☆ Simple development

Distributed database

☆ In these types of databases, a single logical database is spread physically across computers that are at multiple locations.
☆ The computers are connected via a communication link.
☆ The distributed database and decentralized database are not the same.
☆ The maintenance cost is high.
☆ The system is safe from the independent failure of components.

Why a distributed database?

☆ Business unit autonomy and distribution
☆ Data sharing
☆ Data communication costs
☆ Data communication reliability and costs
☆ Multiple application vendors
☆ Database recovery
☆ Fault tolerance
☆ Transaction and analytic processing

Parallel database

☆ This database seeks to improve the performance with the help of parallelism.
☆ The processing and input/output speeds are improved as compared to other databases.
☆ Types of parallelism used are- independent parallelism, pipelined parallelism, interoperation parallelism, interquery parallelism.

Why a parallel databases?

☆ Improved performance
☆ Improved availability of data
☆ Distributed access of data is provided
☆ Improved reliability

Decentralized database

☆ In this database, the information is not stored at a centralized location but is distributed among various computers at different locations.
☆ All the computers are connected with each other.
☆ It is different from the distributed database.
☆ In this type of database, there are multiple central owners.
☆ This database is more secure as compared to centralized.
☆ In the case of system failure, the centralized will crash immediately but in the case of decentralization, the system will work even if only one server is active.
☆ This database system is more expensive than a centralized system.
☆ It has more privacy risks to users.

Why a decentralized system?

☆ Less likely to fail
☆ Better performance
☆ More diverse and flexible system