Components of database manager

The above functions are reached by the database manager. The major elements of a database manager are:

• Authorisation control: This module checks in which the user has required authorisation to carry out the essential function.
• Command Processor: Once the system has checked in which the user has influence to carry out the operation, control is passed to the command processor, that changes commands to a logical series of steps.
• Integrity checker: For an operation in which vary the database, the integrity checker checks in which the requested operation satisfies all nessesary integrity constraints like as key constraints.
• Query Optimiser: This module displays an optimal strategy for the query implementation.
• Transaction Manager: This module performs the essential processing of operations of various transactions. The transaction manager remains the tables of authorisation Concurrency. The DBMS might use authorisation tables to permit the transaction manager to make sure in which the user has permission to implement the desired operation on the database. The authorisation tables could only be modified through properly authorised user commands, that are themselves checked besides the authorisation tables.

Components of Database Manager

• Scheduler: This module is liable for ensuring in which transactions or concurrent operations on the database proceed without conflicting along with one another. It manages the associative order in that transaction operations are implemented. A database may also support concurrency control tables to prevent conflicts while concurrent, conflicting commands are implemented. The DBMS checks the concurrency control tables before implementing an operation to make sure that the data used through it is not locked by another statement.

• Recovery Manager: This module makes sure which the database remains in a constant state in the presence of failures. It is responsible for abort or transaction commit in which is failure or success of transaction.

• Buffer Manager: This module is responsible for the transmission of data between major memory and secondary storage, such as tape and disk. The buffer manager and the recovery manager are sometimes collectively referred to as data manager. The buffer manager is sometimes called as cache manager.