From f6ebe815382a61574df5f9452ee9a0ea4ae38f0c Mon Sep 17 00:00:00 2001 From: Brion Vibber Date: Sun, 21 Feb 2010 15:21:18 -0800 Subject: [PATCH] Performance fix for FriendFeed sup interface: MySQL query optimizer was doing a table scan on notice; explicit subquery makes it run much more efficiently, only scanning items within the period under consideration. Standard subquery should be PostgreSQL-compatible. --- actions/sup.php | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/actions/sup.php b/actions/sup.php index 5daf0a1c1d..4e428dfa58 100644 --- a/actions/sup.php +++ b/actions/sup.php @@ -66,10 +66,12 @@ class SupAction extends Action $divider = common_sql_date(time() - $seconds); $notice->query('SELECT profile_id, max(id) AS max_id ' . - 'FROM notice ' . + 'FROM ( ' . + 'SELECT profile_id, id FROM notice ' . ((common_config('db','type') == 'pgsql') ? 'WHERE extract(epoch from created) > (extract(epoch from now()) - ' . $seconds . ') ' : 'WHERE created > "'.$divider.'" ' ) . + ') AS latest ' . 'GROUP BY profile_id'); $updates = array();