From f3f31eaa8e8a07adc0d6769f77f1ccfb129529de Mon Sep 17 00:00:00 2001
From: Sergei Golubchik <serg@mariadb.org>
Date: Fri, 24 Jan 2020 21:10:07 +0100
Subject: [PATCH] bugfix: in long uniques don't check for duplicates more than
 once

in particular, after checking for duplicates in a partitioned table,
do not re-check it for every partition individually
---
 sql/handler.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sql/handler.cc b/sql/handler.cc
index 806d91bdbc5..49a265a9f23 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -6647,7 +6647,7 @@ int handler::ha_write_row(const uchar *buf)
   mark_trx_read_write();
   increment_statistics(&SSV::ha_write_count);
 
-  if (table->s->long_unique_table)
+  if (table->s->long_unique_table && this == table->file)
   {
     if (this->inited == RND)
       table->clone_handler_for_update();