From: GregThib <GregThib@users.noreply.github.com>
Date: Mon, 13 Jul 2015 10:03:50 +0000 (+0200)
Subject: Performance breakthrough
X-Git-Tag: 16.3~220^2
X-Git-Url: https://git.wh0rd.org/?a=commitdiff_plain;h=c2916856541ed82b2f11b5f3ff29b1e4f5cd6b3e;p=tt-rss.git

Performance breakthrough

Improvement in the Purge method for huge performance increase.
"WHERE ref_id IS NOT NULL" is needed by pgsql, not necessarily by mysql.
This is a more standard way to make deletions based on propagation (from ttrss_user_entries) with 1-to-N relations.
---

diff --git a/include/functions.php b/include/functions.php
index 22179e1a..a57c0947 100644
--- a/include/functions.php
+++ b/include/functions.php
@@ -320,8 +320,7 @@
 
 		// purge orphaned posts in main content table
 		$result = db_query("DELETE FROM ttrss_entries WHERE
-			(SELECT COUNT(int_id) FROM ttrss_user_entries WHERE ref_id = id) = 0");
-
+			id NOT IN (SELECT ref_id FROM ttrss_user_entries WHERE ref_id IS NOT NULL)");
 		if ($do_output) {
 			$rows = db_affected_rows($result);
 			_debug("Purged $rows orphaned posts.");