From 94c43fcc33fc53a10bf9453133fc6c581a6a0556 Mon Sep 17 00:00:00 2001
From: Oliver Gorwits <oliver@cpan.org>
Date: Wed, 3 Aug 2022 15:04:12 +0100
Subject: [PATCH] #906 snmp browser is very slow sometimes

---
 .../Netdisco/DB/Result/Virtual/OidChildren.pm | 13 ++------
 lib/App/Netdisco/Web/Plugin/Device/SNMP.pm    | 33 +++++++++++++------
 2 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/lib/App/Netdisco/DB/Result/Virtual/OidChildren.pm b/lib/App/Netdisco/DB/Result/Virtual/OidChildren.pm
index 4d380efa..97575393 100644
--- a/lib/App/Netdisco/DB/Result/Virtual/OidChildren.pm
+++ b/lib/App/Netdisco/DB/Result/Virtual/OidChildren.pm
@@ -11,20 +11,11 @@ __PACKAGE__->table_class('DBIx::Class::ResultSource::View');
 __PACKAGE__->table("oid_children");
 __PACKAGE__->result_source_instance->is_virtual(1);
 __PACKAGE__->result_source_instance->view_definition(<<ENDSQL
-
-    SELECT DISTINCT(db.oid_parts[?]) AS part, count(distinct(db2.oid_parts[?])) as children
+    SELECT DISTINCT(db.oid_parts[?]) AS part, count(distinct(db.oid_parts[?])) as children
       FROM device_browser db
-
-      LEFT JOIN device_browser db2
-      ON (db2.oid LIKE ? || '.%'
-          AND db2.oid_parts[?] = db.oid_parts[?]
-          AND db2.ip = db.ip)
-
       WHERE db.ip = ?
             AND db.oid LIKE ? || '.%'
-
-      GROUP BY db.oid_parts
-
+      GROUP BY db.oid_parts[?], db.oid_parts
 ENDSQL
 );
 
diff --git a/lib/App/Netdisco/Web/Plugin/Device/SNMP.pm b/lib/App/Netdisco/Web/Plugin/Device/SNMP.pm
index 83af45f4..a65e1bc3 100644
--- a/lib/App/Netdisco/Web/Plugin/Device/SNMP.pm
+++ b/lib/App/Netdisco/Web/Plugin/Device/SNMP.pm
@@ -123,17 +123,30 @@ sub _get_snmp_data {
     my @parts = grep {length} split m/\./, $base;
     ++$recurse;
 
+    # psql cannot cope with bind params and group by array element
+    # so we build a static query instead.
+
+    my $next_part  = (scalar @parts + 1);
+    my $child_part = (scalar @parts + 2);
+    my $query = <<QUERY;
+  SELECT db.oid_parts[$next_part] AS part,
+         count(distinct(db.oid_parts[$child_part])) as children
+    FROM device_browser db
+    WHERE db.ip = ?
+          AND db.oid LIKE ? || '.%'
+    GROUP BY db.oid_parts[$next_part]
+QUERY
+    my $rs = schema('netdisco')->resultset('Virtual::GenericReport')->result_source;
+    $rs->view_definition($query);
+    $rs->remove_columns($rs->columns);
+    $rs->add_columns(qw/part children/);
+
     my %kids = map { ($base .'.'. $_->{part}) => $_ }
-               schema('netdisco')->resultset('Virtual::OidChildren')
-                                 ->search({}, { bind => [
-                                     (scalar @parts + 1),
-                                     (scalar @parts + 2),
-                                     $base,
-                                     (scalar @parts + 1),
-                                     (scalar @parts + 1),
-                                     $ip,
-                                     $base,
-                                 ] })->hri->all;
+                   schema('netdisco')->resultset('Virtual::GenericReport')
+                   ->search(undef, {
+                     result_class => 'DBIx::Class::ResultClass::HashRefInflator',
+                     bind => [$ip, $base],
+                   })->hri->all;
 
     return [{
       text => 'No SNMP data for this device.',