Storage manager: program module that provides interface between the low- level data stored in the database and the application programs that submit queries to the system.

The storage manager is responsible for the following tasks:

• Interaction with the file manager (OS)
• efficient storage, retrieval and updating of data

Components:

• authorization/integrity manager: perform authorization and . enforce integrity constraints.

• transaction manager - make sure each transaction is Atomic, meaning either happening completely or not at all.

• file manager - keeps track of logical mapping between data and files.

• buffer manager - us buffering policies, to speed up data access.

• Stores

  • data (relations)

  • data dictionary (sometimes called catalog or metadata)

  • indexes