From 2f5f1a4d641c5873c308d6ab58ae239f2758e1e4 Mon Sep 17 00:00:00 2001
From: zotlabs <mike@macgirvin.com>
Date: Tue, 14 Mar 2017 16:14:05 -0700
Subject: fix group by item query

---
 include/items.php | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/include/items.php b/include/items.php
index 58305aa63..1037f9814 100755
--- a/include/items.php
+++ b/include/items.php
@@ -3674,7 +3674,7 @@ function zot_feed($uid,$observer_hash,$arr) {
 	if(! is_sys_channel($uid))
 		$sql_extra = item_permissions_sql($uid,$observer_hash);
 
-	$limit = " LIMIT 100 ";
+	$limit = " LIMIT 5000 ";
 
 	if($mindate > NULL_DATE) {
 		$sql_extra .= " and ( created > '$mindate' or changed > '$mindate' ) ";
@@ -3686,15 +3686,7 @@ function zot_feed($uid,$observer_hash,$arr) {
 	}
 
 
-	$items = array();
-
-	/** @FIXME re-unite these SQL statements. There is no need for them to be separate. The mySQL is convoluted with misuse of group by. As it stands, there is a slight difference where the postgres version doesn't remove the duplicate parents up to 100. In practice this doesn't matter. It could be made to match behavior by adding "distinct on (parent) " to the front of the selection list, at a not-worth-it performance penalty (page temp results to disk). duplicates are still ignored in the in() clause, you just get less than 100 parents if there are many children. */
-
-	if(ACTIVE_DBTYPE == DBTYPE_POSTGRES) {
-		$groupby = '';
-	} else {
-		$groupby = 'GROUP BY parent';
-	}
+	$items = [];
 
 	$item_normal = item_normal();
 
@@ -3703,7 +3695,7 @@ function zot_feed($uid,$observer_hash,$arr) {
 			WHERE uid != %d
 			$item_normal
 			AND item_wall = 1
-			and item_private = 0 $sql_extra $groupby ORDER BY created ASC $limit",
+			and item_private = 0 $sql_extra ORDER BY created ASC $limit",
 			intval($uid)
 		);
 	}
@@ -3711,19 +3703,25 @@ function zot_feed($uid,$observer_hash,$arr) {
 		$r = q("SELECT parent, created, postopts from item
 			WHERE uid = %d $item_normal
 			AND item_wall = 1
-			$sql_extra $groupby ORDER BY created ASC $limit",
+			$sql_extra ORDER BY created ASC $limit",
 			intval($uid)
 		);
 	}
 
+	$parents = [];
+
 	if($r) {
-		for($x = 0; $x < count($r); $x ++) {
-			if(strpos($r[$x]['postopts'],'nodeliver') !== false) {
-				unset($r[$x]);
-			}
+		foreach($r as $rv) {
+			if(array_key_exists($rv['parent'],$parents))
+				continue;
+			if(strpos($rv['postopts'],'nodeliver') !== false)
+				continue;
+			$parents[$rv['parent']] = $rv;
+			if(count($parents) > 200)
+				break;
 		}
 
-		$parents_str = ids_to_querystr($r,'parent');
+		$parents_str = ids_to_querystr($parents,'parent');
 		$sys_query = ((is_sys_channel($uid)) ? $sql_extra : '');
 		$item_normal = item_normal();
 
-- 
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