This semester is finally over. After several tough final exams, I can have a rest and make some conclusions of this semester. I have to say that the database course is the most impressive course in this semester and I learned a lot in this course other than the knowledge itself.

First of all, database course shows us a new way of learning. Instead of the teacher-student mode, we learn knowledge by a book-student-student mode. From my stand point, this study mode has both its advantage…

Preparing for the final presentation

Time flies, It’s the time for our final presentation of our project. Though I feel like I was still enjoying the life in toyhouse, we have already finished our project and it’s the time to show it. Our group has struggled a lot in this project and most of us has learned a lot through it. Fortunately, or someone says unfortunately, we are the last group to show our project. I think it is a good choice for us to show our project in the last. At that…

Thank you.

After we learned ordered, hash, clustery methodology, let’s get back to SQL optimizer and see what a SQL engine do when you enter a SQL query.

First of all, what is SQL optimizer and why should we use that? As what is introduced by FuXiao, SQL optimizer is used to reduce the total calculation and input and output for a certain SQL query. As what is stated in the table, for this SQL query, without an optimizer, 220000 I/O should be done while only 3000 I/O…

What I learned this week(week 11)

This week, I learned something about SQL optimizer.

First of all, what is SQL optimizer and why should we use that? As what is introduced by FuXiao, SQL optimizer is used to reduce the total calculation and input and output for a certain SQL query. As what is stated in the table, for this SQL query, without an optimizer, 220000 I/O should be done while only 3000 I/O are needed after it is optimized by an SQL optimizer.

However, SQL…