Which are two strategies to maintain performance and improve a table segment’s compression ratio when you are using Advanced Row Compression on a table segment?
A.
Use smaller database block size.
B.
Use larger database block size.
C.
Use direct-path inserts wherepossible.
D.
IncreasePCTFREEon the table segment.
E.
Increase the size of the tablespace.
AE
BC
AE
BC
The greater duplication the greater the compression – Space usage reduction gives the best results where the most duplicate data is stored (low cardinality)
– Sorting data (on the columns with the most duplicates) may increase the compression ratio
– Larger block sizes may provide higher compression ratios – always test first
https://www.oracle.com/us/assets/lad-2015-ses16380-pedregal-2604876.pdf