HQL/MySQL for listing distincts and duplicates - mysql

Question

I have list of 20.000+ objects. These objects have a fk to a table called title. Two tipps are considered duplicate if they are linked to the same title, and they belong to the same package(tipp_pkg_fk, this is a parameter).
I need a list of all objects, with the duplicates listed together. For example:
tippA.title.name = "One"
tippB.title.name = "Two"
tippC.title.name = "Two"
Ideally from the above I will get a list result like this: [[tippA],[tippB,tippC]]
I am not sure how to do this, I have made an attempt (first in Mysql so I can test it, then ill change it to HQL):
select tipp.tipp_id, 1 as sortOrder
from (select distinct a.tipp_id as id
from title_instance_package_platform a, title_instance_package_platform b
where a.tipp_pkg_fk= 1 and b.tipp_pkg_fk = 1 and a.tipp_ti_fk = b.tipp_ti_fk) duplicates,
title_instance_package_platform tipp
where tipp.tipp_id != duplicates.id
union all
select duplicates.id, 2 as sortOrder
from (select distinct a.tipp_id as id
from title_instance_package_platform a , title_instance_package_platform b
where a.tipp_pkg_fk = 1 and b.tipp_pkg_fk=1 and a.tipp_ti_fk = b.tipp_ti_fk) duplicates
order by sortOrder, id;
This executed for 330 seconds, then I got the message fetching in MySQL workbench, and computer started dying at that point. So the idea is that first I select all the IDs that are not duplicate, then I select all the IDS that are duplicate, and then I merge them and order them so that they appear together. I am looking for the most efficient way to do this, as I will be executing this query several times during an overnight job.
For my TIPP model, the following are part of the mapping:
static mapping = {
pkg column:'tipp_pkg_fk', index: 'tipp_idx'
title column:'tipp_ti_fk', index: 'tipp_idx'
}
+-----------------------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------------------+--------------+------+-----+---------+----------------+
| tipp_id | bigint(20) | NO | PRI | NULL | auto_increment |
| tipp_version | bigint(20) | NO | | NULL | |
| tipp_pkg_fk | bigint(20) | NO | MUL | NULL | |
| tipp_plat_fk | bigint(20) | NO | MUL | NULL | |
| tipp_ti_fk | bigint(20) | NO | MUL | NULL | |
| date_created | datetime | NO | | NULL | |
| last_updated | datetime | NO | | NULL | |
+-----------------+---------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+---------------+------+-----+---------+----------------+
| ti_id | bigint(20) | NO | PRI | NULL | auto_increment |
| ti_version | bigint(20) | NO | | NULL | |
| date_created | datetime | NO | | NULL | |
| ti_imp_id | varchar(255) | NO | MUL | NULL | |
| last_updated | datetime | NO | | NULL | |
| ti_title | varchar(1024) | YES | | NULL | |
| ti_key_title | varchar(1024) | YES | | NULL | |
| ti_norm_title | varchar(1024) | YES | | NULL | |
| sort_title | varchar(1024) | YES | | NULL | |
+-----------------+---------------+------+-----+---------+----------------+
Update
After some changes it is working:
select tipp.tipp_id as id, 1 as sortOrder
from
title_instance_package_platform tipp
where tipp.tipp_id not in (select distinct a.tipp_id as id
from title_instance_package_platform a, title_instance_package_platform b
where a.tipp_pkg_fk= 1 and b.tipp_pkg_fk = 1 and a.tipp_ti_fk = b.tipp_ti_fk)
union all
select duplicates.id as id, 2 as sortOrder
from (select distinct a.tipp_id as id
from title_instance_package_platform a , title_instance_package_platform b
where a.tipp_pkg_fk = 1 and b.tipp_pkg_fk=1 and a.tipp_ti_fk = b.tipp_ti_fk) duplicates
order by sortOrder, id;
I still haven't got the duplicates grouped together though, instead everything comes as a list, which means I still need to group them.

Answer 1

Can you do your select from the other side?
select all titles and packages and list all tipps to these, only if a tipp exists (count > 0) and bundle these together to get the array you showed?

Answer 2

Seems like you could compute both the dups and the non-dups at the same time. Something like
SELECT ( a.tipp_ti_fk = b.tipp_ti_fk ) AS sortOrder,
a.tipp_id as id
from title_instance_package_platform a ,
title_instance_package_platform b
where a.tipp_pkg_fk = 1
and b.tipp_pkg_fk = 1
You might need a DISTINCT.
This composite index would help:
INDEX(tipp_pkg_fk, tipp_ti_fk, tipp_id)