Logical structure of database

hi
i really appreciate the answer i got fro u guys about the table , iam clear now i have a question why do i need to have a logical structure over a physical structure called table, ultimately my data is in db blocks , so can we say that when i query a row in a emp table
dbms checks---- which tablespace the table belongs to
----which segment in that tablespace the table data is sitting and then it goes to extent and finally retrieves from the hard disk
so can we say the retrieval becomes easier
am i correct , pls give a simple explanation as to what is the benefit

It would be a very good idea to go through this book:
http://download-east.oracle.com/docs/cd/B10501_01/server.920/a96524/toc.htm
To get the correct and good undratanding of these concepts.

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    user13345475 wrote:
    as datafile is also a name given to memory area on disk driveNo it is not. There are no "+memory areas+" on disk. The closest to that will be a virtual memory page that has been written to disk (e.g. written to a raw swap device or to a swap file).
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    Hi,
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    http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/intro.htm#sthref53

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