forked from docs/doc-exports
Lu, Huayi
a24ca60074
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com> Co-authored-by: Lu, Huayi <luhuayi@huawei.com> Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
4.2 KiB
4.2 KiB
Case: Creating an Appropriate Index
Symptom
Query the information about all personnel in the sales department.
1 2 3 4 5 6 7 | SELECT staff_id,first_name,last_name,employment_id,state_name,city FROM staffs,sections,states,places WHERE sections.section_name='Sales' AND staffs.section_id = sections.section_id AND sections.place_id = places.place_id AND places.state_id = states.state_id ORDER BY staff_id; |
Optimization Analysis
The original execution plan is as follows before creating the places.place_id and states.state_id indexes:
The optimized execution plan is as follows (two indexes have been created on the places.place_id and states.state_id columns):
Parent topic: Optimization Cases