From a78d43478d924eab749b18c59437eb1dbd962032 Mon Sep 17 00:00:00 2001
From: Jared Hancock <jared@osticket.com>
Date: Thu, 17 Oct 2013 13:23:44 +0000
Subject: [PATCH] Reduce cost of deleting orphaned files
Previous explain included a nested sub-select, which exponentially increased
the count of the rows to be examined. This patch eliminates one layer of
nesting on the sub-select and dramatically increases the performance finding
orphaned files.
Fixes #773
References:
http://www.osticket.com/forums/forum/osticket-1-7-latest-release/troubleshooting-and-problems-aa/9446-version-1-7-much-slower-than-1-6
---
include/class.file.php | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/include/class.file.php b/include/class.file.php
index d53ff3d50..bc432b69b 100644
--- a/include/class.file.php
+++ b/include/class.file.php
@@ -328,15 +328,12 @@ class AttachmentFile {
/* static */ function deleteOrphans() {
$sql = 'DELETE FROM '.FILE_TABLE.' WHERE id NOT IN ('
- # DISTINCT implies sort and may not be necessary
- .'SELECT DISTINCT(file_id) FROM ('
- .'SELECT file_id FROM '.TICKET_ATTACHMENT_TABLE
- .' UNION ALL '
- .'SELECT file_id FROM '.CANNED_ATTACHMENT_TABLE
- .' UNION ALL '
- .'SELECT file_id FROM '.FAQ_ATTACHMENT_TABLE
- .') still_loved'
- .') AND `ft` = "T"';
+ .'SELECT file_id FROM '.TICKET_ATTACHMENT_TABLE
+ .' UNION '
+ .'SELECT file_id FROM '.CANNED_ATTACHMENT_TABLE
+ .' UNION '
+ .'SELECT file_id FROM '.FAQ_ATTACHMENT_TABLE
+ .") AND `ft` = 'T'";
db_query($sql);
--
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