程序代写代做代考 explain_plans
explain_plans
By creating index on id of table student , it is over 30 times faster.
The performance improves by using index.
Query 1
Query 2
The optimized one doesn’t join the table course , the usage of student_id_index and
Transcript_studId_index also improves the performance.
Query 3
The usage of Professor_name_index , Teaching_profId_index , and
Transcript_crsCode_index makes the execution much faster.
Query 4
The usage of course_deptId_index , Transcript_crsCode_index , and
Query 5
student_id_index improves the performance.
The usage of course_deptId_index , Transcript_crsCode_index , and
student_id_index improves the performance.
Query 6
