Details
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Bug
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Status: Open (View Workflow)
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Major
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Resolution: Unresolved
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13.2
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None
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Unexpected results
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Q4/2026 Server Maintenance
Description
Issue:
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After MDEV-41340 fix , stmt isn't pushed down to remote server but explain output still shows "PUSHED"
Issue details:
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Create view with LIMIT : Multi update succeeds i.e. there is No pushdown --But explain shows pushed derived ,bug ??
Query:
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create view v1 as select * from s1 limit 1;
UPDATE s1 JOIN v1 SET s1.a = 1 where v1.a <3; //Note: s1 is table
General log:
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4 Query UPDATE `s1` SET `a` = 1 WHERE `a` = 2 LIMIT 1
4 Query UPDATE `s1` SET `a` = 1 WHERE `a` = 3 LIMIT 1
Series of update..LIMIT1 stmt , so it's confirmed ,stmt isn't pushed down to remote server.
MariaDB [m8]> explain UPDATE s1 JOIN v1 SET s1.a = 1 where v1.a <3; |
+------+----------------+------------+------+---------------+------+---------+------+------+-------------+ |
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | |
+------+----------------+------------+------+---------------+------+---------+------+------+-------------+ |
| 1 | PRIMARY | <derived2> | ALL | NULL | NULL | NULL | NULL | 2 | Using where | |
| 1 | PRIMARY | s1 | ALL | NULL | NULL | NULL | NULL | 3 | | |
| 2 | PUSHED DERIVED | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | |
+------+----------------+------------+------+---------------+------+---------+------+------+-------------+ |
Version used:
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Branch : 13.2-MDEV-39226-direct-multi_table-update-delete
commit: 2db22df80520f0196b0c518e6bb146b07739ff3f
Version : 13.1.0
How to repeat:
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Slave:
create table s1( a int); |
Master: Start server with federated engine enabled
create table s1(a int) ENGINE="FEDERATED" CONNECTION='mysql://u3:pass1@127.0.0.1:3306/m8/s1'; |
insert into s1 values (1),(2),(3); |
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set global federated_pushdown=ON; |
drop view if exists v1; |
create view v1 as select * from s1 limit 1; |
explain UPDATE s1 JOIN v1 SET s1.a = 1 where v1.a <3; //Notice: Explain output shows pushed derived. |
Attachments
Issue Links
- is caused by
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MDEV-39226 Direct multi-table update/delete interface and FederatedX implementation
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- In Testing
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