[MDEV-19518] Introduce an optimizer_switch flag for EARLY NULL FILTERING with ranges Created: 2019-05-17  Updated: 2023-10-12

Status: Open
Project: MariaDB Server
Component/s: Optimizer
Fix Version/s: None

Type: Task Priority: Major
Reporter: Varun Gupta (Inactive) Assignee: Igor Babaev
Resolution: Unresolved Votes: 0
Labels: None

Issue Links:
Relates
relates to MDEV-15777 Use inferred IS NOT NULL predicates i... Closed

 Description   

Introduce an optimizer_switch flag named not_null_range_scan, which by default would be set to off for 10.3.
This is in relation with MDEV-15777

Make sure that this gets documented too

 Comments   
Comment by Sergei Golubchik [ 2019-05-21 ]

Why? Are there cases when it makes queries slower?

Comment by Varun Gupta (Inactive) [ 2019-05-21 ]

serg they are cases in which the queries becomes slower, in the code we try to force usage of index instead of table scan, so now we would have a range access instead of table scan
And the range scan actually scans the entire table
range scan is on a condition t1.a IS NOT NULL.
Also the patch for MDEV-15777 would go to 10.3, so we just wanted to have a switch for it and enable it in 10.5

Comment by Ralf Gebhardt [ 2023-10-12 ]

I have removed the fixVersion for this task as it is one of 5.5, 10.1, 10.2, 10.3, which are EOLed.

Please add a new fixVersion if you plan to work on this task for a not EOLed versions.

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