1. Why did you change the code on how to achieve sub-query table after table 2. points table
We first need to research
For example, the amount of data that in the end to what extent, then you need to import the amount of data
Then our SQL how to write, to verify specific performance is not enough to see
If the query time is longer, to justify points table
Then watch how specific sub-points, need to go through the discussion
After completion points table, write SQL to verify whether looking to meet
After doing these things to come to the table what conclusions should be divided into