Introduction - If you have any usage issues, please Google them yourself
In this paper, on the one hand, to produce the form of examples of the types of data on the situation of the blockade, on the other hand, the theoretical point of view from the database to be analyzed in order to make the reader not only know-and know所以然, so that readers can be more in-depth understanding of Oracle data blockade mechanism, rather than simply to remember some of the conclusions.