Unwatched fix #7548
Unwatched fix #7548
Conversation
Signed by Shawn Bulen, bulens@pacbell.net
|
Tested the fix on my forum and this solves the problem I have been having. |
| @@ -911,6 +912,7 @@ function UnreadTopics() | |||
| AND t.id_last_msg >= {int:min_message} | |||
| AND COALESCE(lt.id_msg, lmr.id_msg, 0) < t.id_last_msg' . ($modSettings['postmod_active'] ? ' | |||
| AND ms.approved = {int:is_approved}' : '') . ' | |||
| AND COALESCE(lt.unwatched, 0) != 1 | |||
There was a problem hiding this comment.
possible performance degradation,
someone with a big dataset/setup should test this coalesce approache.
There was a problem hiding this comment.
Why? Concerned that it won't use the index?
There was a problem hiding this comment.
this concerns didn't exists,
since the awnser is known -> it can't use a index.
the question is,
do it matter that no index can be used.
There was a problem hiding this comment.
There was never an index on this column to begin with.
There was a problem hiding this comment.
yea i know, but still someone had to test if the new filter had somekind of negativ impact,
in this cases where filter didn't happen before.
|
Thanks @live627 ! This fix was tested on two pretty large forums - one with ~245K messages and one with ~300K messages. No performance issues. I think we're good. I do think it's possible to get a performance hit, but only under unusual circumstances, e.g., a user with 100K+ unread messages and thousands of watched/unwatched topics. But that would be a real edge condition, and even then I suspect the hit would be minor. |
|
instead of using: AND COALESCE(lt.unwatched, 0) != 1to use: AND (lt.unwatched != 1 or lt.unwatched is null)would allow the database to had a better understand what you request and could better optimize the query when needed. |
This extends pr #6908 logic to the temp table (log_topics_unread) used during "ALL UNREAD TOPICS" processing as well. #6908 fixed "Recent Unread Topics", but not "All Unread Topics".
This addresses the issue from the forum: https://www.simplemachines.org/community/index.php?topic=582135.0
The bottom line is that when determining if something is unwatched, you have to have the unwatched field accessible to the query... It's a little counterintuitive here, though, since the table is normally telling you what you are watching. BUT... That same table also tells you when you are explicitly not watching something also...
Note that the temp table log_topics_unread is only used when doing an "ALL UNREAD TOPICS", not when doing an "RECENT UNREAD TOPICS"... For the issue to be visible, you need to click on "Unread Posts" then subsequently click on the "ALL UNREAD TOPICS" button.
Initial testing looks good.
@live627 , I'd appreciate your input.
Also... Fixes #7402