From 8a7690af5723ec22fccd450097cc8fb0e8216649 Mon Sep 17 00:00:00 2001
From: Dries Buytaert <dries@buytaert.net>
Date: Wed, 21 Jun 2000 11:03:54 +0000
Subject: [PATCH] Wheep! Wheep! Major performance optimization for index.php:
we reduced the number of SQL on the mainpage with factor 10 and shortened the
code with 4 lines. There is only *one* optimized SQL query left, being:
$result = db_query("SELECT stories.*, COUNT(comments.sid) AS comments FROM
stories LEFT JOIN comments ON stories.sid = comments.sid WHERE
stories.status = 1 AND stories.time <= $date GROUP BY stories.sid ORDER BY
stories.sid DESC LIMIT $number");
Note: we use a LEFT JOIN to retrieve the number of comments associated
with each story. By retrieving this data now, we elimate a *lot*
of individual queries that would otherwise be required inside the
while-loop. If there is no matching record for the right table in
the ON-part of the LEFT JOIN, a row with all columns set to NULL
is used for the right table. This is required, as not every story
has a counterpart in the comments table (at a given time).
---
index.php | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/index.php b/index.php
index 70b20ac89c61..ccabdf7d1d2d 100644
--- a/index.php
+++ b/index.php
@@ -10,10 +10,18 @@
$date = ($date) ? $date : time();
### Perform query:
-$result = db_query("SELECT * FROM stories WHERE status = 1 AND time <= $date ORDER BY sid DESC LIMIT $number");
+$result = db_query("SELECT stories.*, COUNT(comments.sid) AS comments FROM stories LEFT JOIN comments ON stories.sid = comments.sid WHERE stories.status = 1 AND stories.time <= $date GROUP BY stories.sid ORDER BY stories.sid DESC LIMIT $number");
+ // Note: we use a LEFT JOIN to retrieve the number of comments associated
+ // with each story. By retrieving this data now, we elimate a *lot*
+ // of individual queries that would otherwise be required inside the
+ // while-loop. If there is no matching record for the right table in
+ // the ON-part of the LEFT JOIN, a row with all columns set to NULL
+ // is used for the right table. This is required, as not every story
+ // has a counterpart in the comments table (at a given time).
### Display stories:
while ($story = db_fetch_object($result)) {
+
### Compose more-link:
$morelink = "[ ";
if ($story->article) {
@@ -23,13 +31,11 @@
$bytes = strlen($story->article);
$morelink .= "\"><FONT COLOR=\"$theme->hlcolor2\"><B>read more</B></FONT></A> | $bytes bytes in body | ";
}
- $query = db_query("SELECT sid FROM comments WHERE sid = $story->sid");
- if (!$query) { $count = 0; } else { $count = mysql_num_rows($query); }
$morelink .= "<A HREF=\"article.php?sid=$story->sid";
if (isset($user->umode)) { $morelink .= "&mode=$user->umode"; } else { $morelink .= "&mode=threaded"; }
if (isset($user->uorder)) { $morelink .= "&order=$user->uorder"; } else { $morelink .= "&order=0"; }
if (isset($user->thold)) { $morelink .= "&thold=$user->thold"; } else { $morelink .= "&thold=0"; }
- $morelink .= "\"><FONT COLOR=\"$theme->hlcolor2\">$count comments</FONT></A> ]";
+ $morelink .= "\"><FONT COLOR=\"$theme->hlcolor2\">$story->comments comments</FONT></A> ]";
### Display story:
$theme->abstract($story->aid, $story->informant, $story->time, stripslashes($story->subject), stripslashes($story->abstract), stripslashes($story->comments), $story->category, $story->department, $morelink);
--
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