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Maniphest T146483

Add SHOW EXPLAIN support to Quarry
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Description

It would be nice if Quarry users could find out what plan the database server is using to execute their queries. This should be possible with the [[http://s.petrunia.net/blog/?p=89|SHOW EXPLAIN]] functionality in MariaDB. SHOW EXPLAIN works by describing the plan of an actively executing query, so it can describe plans that traverse views.

The ideal implementation would probably be to automatically run SHOW EXPLAIN on all queries and store the result in parallel with the query output so that the user doesn't have to hit an "explain" button at just the right time to get results. An alternative solution would be to add a checkbox for "explain" near the "submit query" button.

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SubjectRepoBranchLines +/-
Add explain button, and store the connection ID when runninganalytics/quarry/webmaster+111 -35
Customize query in gerrit

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Event Timeline

bd808 created this task.Sep 23 2016, 4:15 PM
Restricted Application added a subscriber: Aklapper. · View Herald TranscriptSep 23 2016, 4:15 PM
zhuyifei1999 added a subscriber: zhuyifei1999.Nov 19 2016, 7:40 AM
Krinkle awarded a token.Jan 9 2017, 9:59 PM
leila added a subscriber: leila.Jan 9 2017, 9:59 PM
zhuyifei1999 moved this task from Backlog to Planning on the Quarry board.Jul 31 2017, 12:38 AM
zhuyifei1999 claimed this task.Jul 31 2017, 1:43 PM

I'll try the button implementation, and show the button when the status is "running", and not store the results. Sometimes when you show explain too early the query plans of subqueries are not ready, so hitting the button just the right time can be harder for quarry itself than for human users.

Anyhow, explaining is for optimizing queries. If the query runs too fast for the user to hit the button, it doesn't really need optimizing :)

gerritbot added a subscriber: gerritbot.Jul 31 2017, 3:23 PM

Change 368805 had a related patch set uploaded (by Zhuyifei1999; owner: Zhuyifei1999):
[analytics/quarry/web@master] Add explain button, and store the connection ID when running

https://gerrit.wikimedia.org/r/368805

gerritbot added a project: Patch-For-Review.Jul 31 2017, 3:23 PM
gerritbot added a comment.Jul 31 2017, 4:12 PM

Change 368805 merged by jenkins-bot:
[analytics/quarry/web@master] Add explain button, and store the connection ID when running

https://gerrit.wikimedia.org/r/368805

Stashbot added a subscriber: Stashbot.Jul 31 2017, 4:22 PM

Mentioned in SAL (#wikimedia-cloud) [2017-07-31T16:22:08Z] <zhuyifei1999_> zhuyifei1999@quarry-runner-01:/srv/quarry$ sudo git fetch; sudo git checkout 6447943 T146483

Stashbot added a comment.Jul 31 2017, 4:28 PM

Mentioned in SAL (#wikimedia-cloud) [2017-07-31T16:28:54Z] <zhuyifei1999_> Restarted celery-quarry-worker on quarry-runner-01 T146483

Stashbot added a comment.Jul 31 2017, 4:31 PM

Mentioned in SAL (#wikimedia-cloud) [2017-07-31T16:31:34Z] <zhuyifei1999_> Repeated for quarry-main-01, but restarted uwsgi T146483

zhuyifei1999 closed this task as Resolved.Jul 31 2017, 4:35 PM

Should be fixed. After cleaning up browser cache there should be an "Explain" button just after "This query is currently executing...".

zhuyifei1999 mentioned this in T195836: Cannot reliably get the EXPLAIN for a query on analytics wiki replica cluster.May 29 2018, 12:58 PM
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