reverted:
--- b/core/modules/dblog/dblog.install
+++ a/core/modules/dblog/dblog.install
@@ -52,10 +52,8 @@
         'description' => 'The severity level of the event; ranges from 0 (Emergency) to 7 (Debug)',
       ],
       'link' => [
+        'type' => 'text',
-        'type' => 'varchar',
-        'length' => 255,
         'not null' => FALSE,
-        'default' => '',
         'description' => 'Link to view the result of the event.',
       ],
       'location'  => [
reverted:
--- b/core/modules/dblog/src/Logger/DbLog.php
+++ a/core/modules/dblog/src/Logger/DbLog.php
@@ -70,7 +70,7 @@
           'message' => $message,
           'variables' => serialize($message_placeholders),
           'severity' => $level,
+          'link' => $context['link'],
-          'link' => substr($context['link'], 0, 255),
           'location' => $context['request_uri'],
           'referer' => $context['referer'],
           'hostname' => Unicode::substr($context['ip'], 0, 128),