英语翻译
As many commands as possible that could execute successfully
given there is a locked row in the table will be permitted.
Oracle will take a lock at the lowest level possible (i.e.,the least restrictive lock possible)
and convert that lock to a more restrictive level if necessary.For example,if you select a row
from a table with the FOR UPDATE clause,two locks will be created.One lock is placed on the
row(s) you selected (and this will be an exclusive lock; no one else can lock that specific row in
exclusive mode).The other lock,a ROW SHARE TABLE lock,is placed on the table itself.This will
prevent other sessions from placing an exclusive lock on the table and thus prevent them from
altering the structure of the table,for example.Another session can modify any other row in
this table without conflict.As many commands as possible that could execute successfully
given there is a locked row in the table will be permitted.