MDEV-24564 Statistics are lost after ALTER TABLEbb-10.5-MDEV-24564

Ever since commit 007f68c37f6b77588866a04d7515aca084ab950d,
ALTER TABLE no longer invokes handler::open() after
handler::commit_inplace_alter_table().

ha_innobase::reload_statistics(): Reload or recompute statistics
after ALTER TABLE.

innodb_notify_tabledef_changed(): A new function to invoke
ha_innobase::reload_statistics().

handlerton::notify_tabledef_changed(): Add the parameter handler*
so that ha_innobase::reload_statistics() can be invoked.

ha_partition::notify_tabledef_changed(),
partition_notify_tabledef_changed(): Pass through the call
to any partitions or subpartitions.

This is based on code that was supplied by Monty.

1 files changed, 8 insertions, 7 deletions

diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 6825fbc8e24..116bfa7fd1c 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -1,6 +1,6 @@
 /*
    Copyright (c) 2000, 2019, Oracle and/or its affiliates.
-   Copyright (c) 2010, 2020, MariaDB
+   Copyright (c) 2010, 2021, MariaDB
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -7934,7 +7934,6 @@ static bool mysql_inplace_alter_table(THD *thd,
   Alter_info *alter_info= ha_alter_info->alter_info;
   bool reopen_tables= false;
   bool res;
-  handlerton *hton;
 
   const enum_alter_inplace_result inplace_supported=
     ha_alter_info->inplace_supported;
@@ -8145,20 +8144,22 @@ static bool mysql_inplace_alter_table(THD *thd,
 
   /* Notify the engine that the table definition has changed */
 
-  hton= table->file->partition_ht();
-  if (hton->notify_tabledef_changed)
+  if (table->file->partition_ht()->notify_tabledef_changed)
   {
     char db_buff[FN_REFLEN], table_buff[FN_REFLEN];
+    handlerton *hton= table->file->ht;
     LEX_CSTRING tmp_db, tmp_table;
-    tmp_db.str=    db_buff;
-    tmp_table.str= table_buff;
+
+    tmp_db.str=       db_buff;
+    tmp_table.str=    table_buff;
     tmp_db.length=    tablename_to_filename(table_list->db.str,
                                          db_buff, sizeof(db_buff));
     tmp_table.length= tablename_to_filename(table_list->table_name.str,
                                             table_buff, sizeof(table_buff));
     if ((hton->notify_tabledef_changed)(hton, &tmp_db, &tmp_table,
                                         table->s->frm_image,
-                                        &table->s->tabledef_version))
+                                        &table->s->tabledef_version,
+                                        table->file))
     {
       my_error(HA_ERR_INCOMPATIBLE_DEFINITION, MYF(0));
       DBUG_RETURN(true);