Data Abstraction

Data Abstraction-

Data abstraction means that hiding implementation   from user. User is the main part of DBMS ,because user use the all DBMS system. If user getting complexity at the time of application use the that DBMS not better for implementation. Data abstraction hides all operation from user which runs in DBMS system mainly. the lots of operation runs in DBMS system if the completing a user expected result and shows the user personally. Data abstraction working for that time and hides working of conceptual and physical level from user. the user only interact with DBMS system with use of views, application program or as a end user.

Their is 3 level of abstraction of data, that all is as fallows-

1.Physical Level-

That is the lowest level of abstraction. In that stage describe hows data was stored in to database mainly. That all process hiding from user.

2.Logical / Conceptual Level:-

That is the 2nd level of abstraction. In that stage describes mainly hows data was related with each other. All query execution task performs here. The DBA is totally responsible for that stage. But in data abstraction that all formation hides from user.

3.View Level:

That is the highest level of data abstraction mainly. In that only shows different angles of databases to user with user requirement,but all background knowledge hidden from user mainly.