961789 - large dependency trees with lots of resolved bugs are very slow to load

Status: RESOLVED FIXED

(Bugzilla :: Dependency Views, defect)

Description

[:glob ✱]

loading the dependency tree on bug 455553 is very slow, even when hide_resolved is enabled.

this is because we currently create objects for every possible bug, then filter on the bug's open state before passing to the template.

by moving the is_open filtering to the db query, i was able to decrease the load time of the default view from 65 seconds down to 900 ms.

Comment 1

[:glob ✱]

Attachment: 961789_1.patch

Comment 2

[:glob ✱]

Attachment: 961789_2.patch

use selectcol_arrayref instead of bind_col.

Comment 3

[:glob ✱]

Attachment: 961789_3.patch

move is_open check into EmitDependList

Comment 4

[Frédéric Buclin]

Comment on attachment 8362610 [details] [diff] [review]
961789_3.patch

>=== modified file 'Bugzilla/Bug.pm'

>+    $cache->{"dependson_sth_$exclude_resolved"} ||= $dbh->prepare(
>+    $cache->{"blocked_sth_$exclude_resolved"} ||= $dbh->prepare(

It doesn't make sense to prepare both statements at once; there is no perf win in doing so. First of all, you duplicate most of the SQL query, and $my_field is no longer used. Simply generate and cache the SQL statement you need.

Comment 5

[:glob ✱]

Attachment: 961789_4.patch

Comment 6

[:glob ✱]

note- this also fixes an issue where an incorrect bug count is shown on the page.

Comment 7

[Frédéric Buclin]

Comment on attachment 8366682 [details] [diff] [review]
961789_4.patch

>=== modified file 'Bugzilla/Bug.pm'

>-          "SELECT $targetfield
>+          "SELECT $target_field AS bug_id

Why appending "AS bug_id"? We call selectcol_arrayref() so the alias has no effect (it's only useful with selectall_hashref()).



>=== modified file 'showdependencytree.cgi'

>         # remove bugs according to visiblity and filters

Remove "and filters" as the single remaining check is the call to can_see_bug().


r=LpSolit with these fixes on checkin.

Comment 8

[:glob ✱]

Committing to: bzr+ssh://[e-mail]/bugzilla/trunk/
modified showdependencytree.cgi
modified Bugzilla/Bug.pm
Committed revision 8910.

Committing to: bzr+ssh://[e-mail]/bugzilla/4.4/
modified showdependencytree.cgi
modified Bugzilla/Bug.pm
Committed revision 8656.