Empty resultset when joining OQGRAPH tables
Bug #837496 reported by
Stephane VAROQUI
This bug affects 2 people
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| MariaDB |
New
|
Undecided
|
Unassigned | ||
| OQGRAPH |
New
|
Undecided
|
Antony T Curtis | ||
Bug Description
tested on mariadb 5.2.8
Issue SELECT with JOIN OR SUBQUERIES
SELECT * FROM t_oqg WHERE t_oqg.origid IN (1,2,3) AND latch =1;
works fine
SELECT * FROM t_oqg INNER JON t1 ON t1.id = t_oqg.origid WHERE t1.id IN (1,2,3) AND t_oqg.latch =1;
empty result
SELECT * FROM t_oqg WHERE t_oqg.origid IN (SELECT t1.id FROM t1 WHERE t1.id IN (1,2,3)) AND t_oqg.latch =1;
empty result
| affects: | oqgraph → maria |
Revision history for this message
| Arjen Lentz (arjen-lentz) wrote | #1 |
| Changed in oqgraph: | |
| assignee: | nobody → Antony T Curtis (atcurtis) |
Revision history for this message
| Steven Peckins (sep16) wrote | #2 |
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Interesting, Stephane. I haven't seen a join fail like this before.
One issue might be the join-order that the optimiser works out for your join, likely it'll do t1 first and that might create a problem, as looking up origid makes no sense, it should be "stuffed in to" the engine so it can do its calculations. The subquery does something similar.
Do you have EXPLAIN output for this, and possibly a debug log so we can see what the optimiser is thinking?
thanks