Which two statements correctly describe the relation between a data file and the logical database
structures? (Choose two.)
A.
An extent cannot spread across data files.
B.
A segment cannot spread across data files.
C.
A data file can belong to only one tablespace.
D.
A data file can have only one segment created in it.
E.
A data block can spread across multiple data files as it can consist of multiple operating system
(OS) blocks.
An extent is a logical unit of database storage space allocation made up of a number of contiguous data blocks. One or more extents in turn make up a segment. When the existing space in a segment is completely used, Oracle allocates a new extent for the segment.
Oracle looks for free space to allocate to a new extent. If that datafile does not have enough adjacent free space, then Oracle looks in another datafile.
A segment is a set of extents that contains all the data for a specific logical storage structure within a tablespace. For example, for each table, Oracle allocates one or more extents to form that table’s data segment, and for each index
A data block is the smallest unit of data used by a database. In contrast, at the physical, operating system level, all data is stored in bytes