sql> select x.ksppinm name, y.ksppstvl value, x.ksppdesc describ
2 from sys.x$ksppi x, sys.x$ksppcv y
3 where x.inst_id = userenv ('instance')
4 and y.inst_id = userenv ('instance')
5 and x.indx = y.indx
6 and x.ksppinm like '%&par%'
7 /
enter value for par: blocks
old 6: and x.ksppinm like '%&par%'
new 6: and x.ksppinm like '%blocks%'

name value describ
------------------------------ 
_log_blocks_during_backup true log 
block images when changed during backup