csv upload performance
Reported by shawn (at vegantech) | March 14th, 2011 @ 06:28 AM | in Evaluate to see if applicable.
for example student groups
add mapped columns that are indexed integers and only do the
expensive join once.
insert into groups_students
(student_id,group_id)
select u.id , g.id from student_groups_1001893421_importer tug inner join
students u use index district_id on u.district_student_id = tug.district_student_id
inner join groups g
on tug.district_group_id = g.district_group_id
and u.district_id = 1001893421
where not exists (
select 1 from groups_students gs
where gs.group_id = g.id and gs.student_id = u.id)
group by u.id,g.id
Comments and changes to this ticket
-
-
shawn (at vegantech) March 28th, 2011 @ 03:40 PM
- Milestone changed from “For Jan 2011 DPI meeting” to “For Apr 2011 DPI Meeting”
- Milestone order changed from “69” to “0”
-
shawn (at vegantech) November 9th, 2012 @ 07:26 PM
- Milestone changed from “For Apr 2011 DPI Meeting” to “Evaluate to see if applicable.”
- Milestone order changed from “73” to “0”
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Student Intervention Monitoring System
shawn (at vegantech)