[MDEV-6995] EXPLAIN JSON and ORDER BY, GROUP BY, etc - Jira

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Type: Task
Status: Open (View Workflow)
Priority: Major
Resolution: Unresolved
Fix Version/s: None
Component/s: None
Labels:
- explain_json

Description

We need to support ORDER/GROUP BY in EXPLAIN JSON.

MySQL's way of doing it has some good ideas: ordering_operation and grouping_operation are two different ops that one can see. But it has issues, too:

ordering_operation is present even when no ordering takes place http://bugs.mysql.com/bug.php?id=74462
they show "using_temporary_table": true for both duplicates_removal and "ordering_operation" http://bugs.mysql.com/bug.php?id=74661 when execution only uses one temp.table
they ignore LIMIT.
ordering_operation is present even when there is no "operation". Is simply using the appropriate index an "ordering operation"?
duplicate_removal may be shown when no duplicate removal takes place: http://bugs.mysql.com/bug.php?id=74744

Attachments

Issue Links

relates to

MDEV-6109 EXPLAIN JSON

Closed

MDEV-7248 EXPLAIN FORMAT=JSON: Better output

Open

MDEV-7836 ANALYZE FORMAT=JSON should provide info about GROUP BY

Stalled

MDEV-7854 ANALYZE FORMAT=JSON should provide info about used tmp.tables

Open

Activity

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Assignee:: Sergei Petrunia

Reporter:: Sergei Petrunia

Votes:: 0 Vote for this issue

Watchers:: 2 Start watching this issue

Dates

Created:: 2014-11-01 03:00

Updated:: 2015-10-30 13:05

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