andmebaasihaldussüsteemide

andmebaasihaldussüsteem (ABHS) are software systems that store, manipulate, and retrieve data for applications and users. They provide interfaces for data definition, access, integrity, and security, allowing multiple users and processes to share data concurrently. An ABHS typically includes a data definition language, a query language, and transaction processing capabilities that support atomicity, consistency, isolation, and durability (ACID). The database engine handles storage, indexing, and caching, while the query optimizer translates user requests into efficient execution plans.

ABHS are classified mainly into relational, object‑oriented, document, column‑store, graph, and key‑value models. Relational databases dominate enterprise environments; their schema‑driven design relies on structured tables and declarative SQL queries. Document stores such as MongoDB handle semi‑structured JSON documents, suitable for web applications, whereas graph databases like Neo4j excel at relationships and network analysis. Column‑store systems such as Apache Parquet are used for analytical workloads, and key‑value stores like Redis provide fast, in‑memory access for caching or session management.

Common examples include Oracle, Microsoft SQL Server, PostgreSQL, MySQL, SQLite, and IBM Db2 for relational installations; MongoDB, Cassandra, and Couchbase for NoSQL options; and ElasticSearch for full‑text search. Open‑source implementations allow lower costs and community support, while commercial vendors provide advanced features, scalability, and managed services. Overall, an ABHS plays a central role in modern software architecture, enabling reliable, concurrent, and secure data management across diverse applications.