<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (September 2014) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (September 2014) (Learn how and when to remove this template message) </Td> </Tr> <P> A database abstraction layer (DBAL) is an application programming interface which unifies the communication between a computer application and databases such as SQL Server, DB2, MySQL, PostgreSQL, Oracle or SQLite . Traditionally, all database vendors provide their own interface tailored to their products, which leaves it to the application programmer to implement code for all database interfaces he or she would like to support . Database abstraction layers reduce the amount of work by providing a consistent API to the developer and hide the database specifics behind this interface as much as possible . There exist many abstraction layers with different interfaces in numerous programming languages . If an application has such a layer built in, it is called database - agnostic . </P> <P> The lowest level connects to the database and performs the actual operations required by the users . At this level the conceptual instruction has been translated into multiple instructions that the database understands . Executing the instructions in the correct order allows the DAL to perform the conceptual instruction . </P>

What do you mean by data abstraction in dbms