From 32c3d775e98696ace49fb34e434ca5963179b37e Mon Sep 17 00:00:00 2001
From: Sergei Golubchik <serg@mariadb.org>
Date: Tue, 31 May 2022 22:06:27 +0200
Subject: [PATCH] Online alter: set read_set early, before row reads

also

* don't modify write_set
* backup/restore rpl_write_set
---
 sql/handler.cc |  9 ++++++---
 sql/table.cc   | 24 +++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/sql/handler.cc b/sql/handler.cc
index 33b9d693894..be3816b7b60 100644
--- a/sql/handler.cc
+++ b/sql/handler.cc
@@ -7272,14 +7272,17 @@ static int binlog_log_row_online_alter(TABLE* table,
       trans_register_ha(thd, true, binlog_hton, 0);
   }
 
-  // We need to log all columns for the case if alter table changes primary key.
-  table->use_all_columns();
-  bitmap_set_all(table->rpl_write_set);
+  // We need to log all columns for the case if alter table changes primary key
+  DBUG_ASSERT(!before_record || bitmap_is_set_all(table->read_set));
+  MY_BITMAP *old_rpl_write_set= table->rpl_write_set;
+  table->rpl_write_set= &table->s->all_set;
 
   int error= (*log_func)(thd, table, table->s->online_alter_binlog,
                          table->online_alter_cache, has_trans,
                          before_record, after_record);
 
+  table->rpl_write_set= old_rpl_write_set;
+
   return unlikely(error) ? HA_ERR_RBR_LOGGING_FAILED : 0;
 }
 #endif // HAVE_REPLICATION
diff --git a/sql/table.cc b/sql/table.cc
index 33d38041f5f..2078470e65c 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -7681,6 +7681,17 @@ void TABLE::mark_columns_needed_for_delete()
     bitmap_set_bit(write_set, s->vers.end_fieldno);
     need_signal= true;
   }
+#ifdef HAVE_REPLICATION
+  if (s->online_alter_binlog)
+  {
+    /*
+      For online alter we have to read all columns, because we need PK columns
+      in the row event, and we don't know what columns will be in PK after ALTER
+    */
+    bitmap_set_all(read_set);
+    need_signal= true;
+  }
+#endif
 
   if (need_signal)
     file->column_bitmaps_signal();
@@ -7767,9 +7778,20 @@ void TABLE::mark_columns_needed_for_update()
       For System Versioning we have to read all columns since we store
       a copy of previous row with modified row_end back to a table.
     */
-    bitmap_union(read_set, &s->all_set);
+    bitmap_set_all(read_set);
     need_signal= true;
   }
+#ifdef HAVE_REPLICATION
+  if (s->online_alter_binlog)
+  {
+    /*
+      For online alter we have to read all columns, because we need PK columns
+      in the row event, and we don't know what columns will be in PK after ALTER
+    */
+    bitmap_set_all(read_set);
+    need_signal= true;
+  }
+#endif
   if (check_constraints)
   {
     mark_check_constraint_columns_for_read();