Logical , Internal Or Physical level ~ AWK KHAN Computer Technology

Logical or conceptual Level
This is the middle level view in three level architecture. The logical or conceptual
level describes the data stored in database. It contains the definition of the data to be stored
in the database. It also contains the rules and information about the structure and type of
data. It is the complete description of data stored in database. That is why it is also known as a community view of the database.This level contains the logical structure of entire database as seen. It hides the details of physical storage instruction physical Storage structure

The conceptual level supports each external view. It means that any data require by
any user must be available from conceptual view. The conceptual model is comparatively
constant. Dba designs a conceptual mode to fulfill the present and future requirements of
the organization. If there is any charge in external model, The conceptual model should
be able to accomodate that change. It is important because any changes in the conceptual
models requires a lot of effort. It also effects other views or levels of the database. the conceptual level is described in conceptual schema. There is only one schema for one database.

Internal Or Physical level

Internal level is responsible to store data on storage media. It describe the physical
representation of database on computer. It describes how the data is stored in database . It
covers the data structures and file organization used to store data on storage devices.
Internal and physical levels are normally considered to be same. But there is a slight method
is implemented by operating systems. DBMS partially decides the way data is stored on the Disk. The binary storage This decisions is based in the specifications of DBA. Additionally
DBMS adds information to the data to be stored For example it selects a specific files
organization for storing data on the disk. It also applies different data encryption
algorithms to implement security on the data.

It performs a storage space utilization to consume minimum space for storing data
The data compressions can be performed for this purpose. It also applies
different data encryption algorithms to implement security on the data.

The records at internal level are presented according to the format of schema difinition
but the data is not in the record format at physical level. It is in character format. The rules
specified by the schema of record are not enforced at physical level. Data is managed
by operating system at physical level. Tweet