DataBase. 7. 5. 2. 6. 8. Contents. 1. Database Definition. Data Management System. 3. 2. Components of DBMS. 4. RDBMS components. Relational Database. Model. Storage structures. Indexing. Database Types. Database Definition.
1-Interface drivers - A user or application program initiates either schema modification or content modification. These drivers[which?] are built on top of SQL. They provide methods to prepare statements, execute statements, fetch results, etc. Examples include DDL, DCL, DML, ODBC, and JDBC. Some vendors provide language-specific proprietary interfaces. For example MySQL provides drivers for PHP, Python, etc.
2-SQL engine - This component interprets and executes the SQL query. It comprises three major components (compiler, optimizer, and execution engine).
3-Transaction engine - Transactions are sequences of operations that read or write database elements, which are grouped together.
4- Relational engine - Relational objects such as Table, Index, and Referential integrity constraints are implemented in this component.
5- Storage engine - This component stores and retrieves data records. It also provides a mechanism to store metadata and control information such as undo logs, redo logs, lock tables, etc.
1- Language drivers - A user or application program initiates either schema modification or content modification via the chosen programming language. The drivers then provide the mechanism to manage object lifecycle coupling of the application memory space with the underlying persistent storage. Examples include C++, Java, .NET, and Ruby.
2- Query engine - This component is responsible for interpreting and executing language-specific query commands in the form of OQL, LINQ, JDOQL, JPAQL, others. The query engine returns language specific collections of objects which satisfy a query predicate expressed as logical operators e.g. >, <, >=, <=, AND, OR, NOT, GroupBY, etc.
3- Transaction engine - Transactions are sequences of operations that read or write database elements, which are grouped together. The transaction engine is concerned with such things as data isolation and consistency in the driver cache and data volumes by coordinating with the storage engine.
4- Storage engine - This component stores and retrieves objects in an arbitrarily complex model. It also provides a mechanism to manage and store metadata and control information such as undo logs, redo logs, lock graphs, etc.
1- Customer databases
2- Personal databases
3- Inventory databases