fix: Split query to fetch board ids to avoid slow query join

[juliushaertl]

Summary

Some over optimization for query count caused this slow query, which does seem to do a full table scan on the boards table (left part of the join):

SELECT DISTINCT b.id FROM oc_deck_boards b 
	LEFT JOIN oc_deck_board_acl acl ON b.id = acl.board_id 
	WHERE (owner = 'user1')
	OR ((acl.participant = 'user1') AND (acl.type = 0)) 
	OR ((acl.participant IN ('group', 'group1')) AND (acl.type = 1));

Doing two queries instead still seems more reasonable as I also couldn't think of a more performant option.

[cypress]

Passing run #1147 ↗︎

0

15

0

0

0

Details:

Merge fe319c8 into 554efab...
Project: Deck	Commit: 8b5edfcc5b ℹ️
Status: Passed	Duration: 02:33 💡
Started: Jul 21, 2023 1:16 PM	Ended: Jul 21, 2023 1:19 PM

_{This comment has been generated by cypress-bot as a result of this project's GitHub integration settings.}

[mejo-]

To be honest I don't understand the change. If I read the code changes correctly, one SQL query is split into two now, but the second new query looks exactly like the old one to me.

The first new query doesn't have the "Shared to [user/groups/circles]" condition, so it returns only the owned boards. But the second still has both conditions: owned boards and shared boards.

Maybe you meant to remove the "Owned by the user" condition from the second query? 🤔

It's well possible that I just don't understand the code. DB queries are certainly not my field of expertise 😬

[mejo-]

Code changes look good to me now 😊

[juliushaertl]

/backport to stable27

[juliushaertl]

/backport to stable26

[backportbot-nextcloud]

The backport to stable27 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable27
git pull origin stable27

# Create the new backport branch
git checkout -b fix/foo-stable27

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable27

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport

[backportbot-nextcloud]

The backport to stable26 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable26
git pull origin stable26

# Create the new backport branch
git checkout -b fix/foo-stable26

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable26

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport