DBMS: Database Management Systems
Data is the cornerstone of any modern software application, and database are the most common way to store and manage data used by applications.
With the explosion of web and cloud technologies, databases have evolved from traditional relational databases to more advanced types of databases such as NoSQL, columnar, key-value, hierarchical, and distributed databases. Each type has the ability to handle structured, semi-structured, and even unstructured data.
On top of that, databases are continuously handling mission-critical and sensitive data. When this is coupled with compliance requirements and the distributed nature of most data sets, managing databases has become highly complex. As a result, organizations require robust, secure, and user-friendly tools to maintain these databases.
This is where database management systems come into play—by offering a platform to manage databases. Let’s take a look.
What is a database management system?
A database management system (DBMS) is a software tool that enables users to manage a database easily. It allows users to access and interact with the underlying data in the database. These actions can range from simply querying data to defining database schemas that fundamentally affect the database structure.
Furthermore, DBMS allow users to interact with a database securely and concurrently without interfering with each user and while maintaining data integrity.
Database tasks in a DBMS
The typical database administrative tasks that can be performed using a DBMS include:
- Configuring authentication and authorization. Easily configure user accounts, define access policies, modify restrictions, and access scopes. These operations allow administrators to limit access to underlying data, control user actions, and manage users in databases.
- Providing data backups and snapshots. DBMS can simplify the backup process of databases by providing a simpler and straightforward interface to manage backups and snapshots. They can even move these backups to third-party locations such as cloud storage for safekeeping.
- Performance tuning. DBMS can monitor the performance of databases using integrated tools and enable users to tune databases by creating optimized indexes. It reduces I/O usage to optimize SQL queries, enabling the best performance from the database.
- Data recovery. In a recovery operation, DBMS provides a recovery platform with the necessary tools to fully or partially restore databases to their previous state—effortlessly.
All these administrative tasks are facilitated using a single management interface. Most modern DBMS support handling multiple database workloads from a centralized DBMS software, even in a distributed database scenario. Furthermore, they allow organizations to have a governable top-down view of all the data, users, groups, locations, etc., in an organized manner.
Components of a database management system
All DBMS comes with various integrated components and tools necessary to carry out almost all database management tasks. Some DBMS software even provides the ability to extend beyond the core functionality by integrating with third-party tools and services, directly or via plugins.
In this section, we will look at the common components that are universal across all DBMS software, including:
- Storage engine
- Query language
- Query processor
- Optimization engine
- Metadata catalog
- Log manager
- Reporting and monitoring tools
- Data utilities
Storage engine
The storage engine is the core component of the DBMS that interacts with the file system at an OS level to store data. All SQL queries which interact with the underlying data go through the storage engine.
Query language
A database access language is essential for interacting with a database, enabling tasks ranging from creating databases to simply inserting or retrieving data. A proper DBMS must support one or multiple query languages and language dialects. Structured Query Language (SQL) and MongoDB Query Language (MQL) represent two query languages also utilized for interacting with databases.
In many query languages, the query language functionality can be further categorized according to specific tasks:
- Data Definition Language (DDL). This consists of commands that can be used to define database schemas or modify the structure of database objects.
- Data Manipulation Language (DML). Commands that directly deal with the data in the database. All CRUD operations come under DML.
- Data Control Language (DCL). This deals with the permissions and other access controls of the database.
- Transaction Control Language (TCL). Command which deals with internal database transactions.
Query processor
This serves as the intermediary between the user queries and the database. The query processor interprets the queries of users and consequently makes them actionable commands that can be understood by the database to perform the appropriate functionality.
Optimization engine
The optimization Engine allows the DBMS to provide insights into the performance of the database in terms of optimizing the database itself and queries. When coupled with database monitoring tools, it can provide a powerful toolset to gain the best performance out of the database.
Metadata catalog
This is the centralized catalog of all the objects within the database. When a user creates an object, the DBMS records that object along with relevant metadata in the metadata catalog. Then, this record can be used to:
- Verify user requests to the appropriate database objects
- Provide an overview of the complete database structure
Log manager
Additionally, this component will keep all the logs of the DBMS. These logs will encompass user logins and activity, database functions, backups and restore functions, etc. The log manager also ensures all these logs are properly recorded and easily accessible.
Reporting & monitoring tools
Reporting and monitoring tools are another standard component that comes with a DBMS. These tool will enable users to generate reports while monitoring tools enable monitoring the databases for resource consumption, user activity, etc.
Data utilities
In addition to all the above, most DBMS software comes with additional inbuilt utilities to provide functionality such as:
- Data integrity checks
- Backup and restore
- Simple database repair
- Data validations
- Etc.
