Which two statements are true about the logical storage structure of an Oracle database?
A.
An extent contains data blocks that are always physically contiguous on disk.
B.
An extent can span multiple segments,
C.
Each data block always corresponds to one operating system block.
D.
It is possible to have tablespaces of different block sizes.
E.
A data block is the smallest unit of I/O in data files.
DE
It should be D and E.
A segment can span multiple extents.
BD
BD
Segments. The level of logical database storage above an extent is called a segment.
A segment is a set of extents that have been allocated for a specific type of data structure, and that all are stored in the same tablespace.
Oracle allocates space for segments in extents.
i do not understand
sorry, it is DE