Re: [sqlite] Query freezing on latest SQLite 3.30.1 build

2019-12-05 Thread David Raymond
The mailing list strips off all attachments, so you'll have to provide another 
place to get that.

Alternatively could you post the schema here as text, along with the explain 
query plan output from the slow version and from a fast version?

-Original Message-
From: sqlite-users  On Behalf Of 
Clovis Ribeiro,MyABCM
Sent: Thursday, December 5, 2019 2:04 PM
To: sqlite-users@mailinglists.sqlite.org
Subject: [sqlite] Query freezing on latest SQLite 3.30.1 build

Folks,

The following query, when executed against the attached database using SQLite 
3.30.1 (running on Windows OS) will take forever to execute. If we remove all 
columns from both tables that are not actually used in the query, it is 
executed in milliseconds.

SELECT COUNT(*) FROM
(SELECT
 src.member_id src_id,
 dst.member_id dst_id,
 asg.contribution_percentage
FROM
 mdl_assignments asg
INNER JOIN
 mdl_member_instances src ON asg.source_mbi_id = src.id
INNER JOIN
 mdl_member_instances dst ON asg.destination_mbi_id = dst.id
WHERE
 src.period_scenario_id = 1 AND dst.period_scenario_id = 1) T

When testing the same query with older versions of SQLite we used in the past 
(more than 6 years ago), the query also executed in milliseconds.

We have executed several different tests but could not figure out why this 
query hangs on the latest version of SQLite but runs fast in older versions or 
when we remove columns from the tables in the database.

Hope this can help you improve SQLite.

Thanks

Clovis Ribeiro
MyABCM

___
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
___
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users


[sqlite] Query freezing on latest SQLite 3.30.1 build

2019-12-05 Thread Clovis Ribeiro,MyABCM
Folks,

The following query, when executed against the attached database using SQLite 
3.30.1 (running on Windows OS) will take forever to execute. If we remove all 
columns from both tables that are not actually used in the query, it is 
executed in milliseconds.

SELECT COUNT(*) FROM
(SELECT
 src.member_id src_id,
 dst.member_id dst_id,
 asg.contribution_percentage
FROM
 mdl_assignments asg
INNER JOIN
 mdl_member_instances src ON asg.source_mbi_id = src.id
INNER JOIN
 mdl_member_instances dst ON asg.destination_mbi_id = dst.id
WHERE
 src.period_scenario_id = 1 AND dst.period_scenario_id = 1) T

When testing the same query with older versions of SQLite we used in the past 
(more than 6 years ago), the query also executed in milliseconds.

We have executed several different tests but could not figure out why this 
query hangs on the latest version of SQLite but runs fast in older versions or 
when we remove columns from the tables in the database.

Hope this can help you improve SQLite.

Thanks

Clovis Ribeiro
MyABCM

___
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users