MDEV-17124: mariadb 10.1.34, views and prepared statements: ERROR 1615 (HY000): Prepared statement needs to be re-prepared

The problem is that if table definition cache (TDC) is full of real tables
which are in tables cache, view definition can not stay there so will be
removed by its own underlying tables.
In situation above old mechanism of detection matching definition in PS
and current version always require reprepare and so prevent executing
the PS.

One work around is to increase TDC, other - improve version check for
views/triggers (which is done here). Now in suspicious cases we check:
 - timestamp (microseconds) of the view to be sure that version really
   have changed;
 - time (microseconds) of creation of a trigger related to time
   (microseconds) of statement preparation.

11 files changed, 235 insertions, 63 deletions

diff --git a/sql/parse_file.cc b/sql/parse_file.cc
index 59b4027a352..18fffb2445d 100644
--- a/sql/parse_file.cc
+++ b/sql/parse_file.cc
@@ -173,11 +173,12 @@ write_parameter(IO_CACHE *file, const uchar* base, File_option *parameter)
   {
     /* string have to be allocated already */
     LEX_STRING *val_s= (LEX_STRING *)(base + parameter->offset);
-    time_t tm= my_time(0);
-
-    get_date(val_s->str, GETDATE_DATE_TIME|GETDATE_GMT|GETDATE_FIXEDLENGTH,
-	     tm);
-    val_s->length= PARSE_FILE_TIMESTAMPLENGTH;
+    // number of microseconds since Epoch, timezone-independent
+    my_hrtime_t tm= my_hrtime();
+    // Paded to 19 characters for compatibility
+    val_s->length= snprintf(val_s->str, MICROSECOND_TIMESTAMP_BUFFER_SIZE,
+                            "%019lld", tm.val);
+    DBUG_ASSERT(val_s->length == MICROSECOND_TIMESTAMP_BUFFER_SIZE-1);
     if (my_b_write(file, (const uchar *)val_s->str,
                     PARSE_FILE_TIMESTAMPLENGTH))
       DBUG_RETURN(TRUE);
@@ -833,16 +834,16 @@ File_parser::parse(uchar* base, MEM_ROOT *mem_root,
 	{
 	  /* string have to be allocated already */
 	  LEX_STRING *val= (LEX_STRING *)(base + parameter->offset);
-	  /* yyyy-mm-dd HH:MM:SS = 19(PARSE_FILE_TIMESTAMPLENGTH) characters */
-	  if (ptr[PARSE_FILE_TIMESTAMPLENGTH] != '\n')
+	  /* 19 characters of timestamp */
+	  if (ptr[MICROSECOND_TIMESTAMP_BUFFER_SIZE-1] != '\n')
 	  {
 	    my_error(ER_FPARSER_ERROR_IN_PARAMETER, MYF(0),
                      parameter->name.str, line);
 	    DBUG_RETURN(TRUE);
 	  }
-	  memcpy(val->str, ptr, PARSE_FILE_TIMESTAMPLENGTH);
-	  val->str[val->length= PARSE_FILE_TIMESTAMPLENGTH]= '\0';
-	  ptr+= (PARSE_FILE_TIMESTAMPLENGTH+1);
+	  memcpy(val->str, ptr, MICROSECOND_TIMESTAMP_BUFFER_SIZE-1);
+	  val->str[val->length= MICROSECOND_TIMESTAMP_BUFFER_SIZE-1]= '\0';
+	  ptr+= MICROSECOND_TIMESTAMP_BUFFER_SIZE;
 	  break;
 	}
 	case FILE_OPTIONS_STRLIST:
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 614d6d58c0b..385040b1e03 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -1906,6 +1906,11 @@ retry_share:
                table_list->alias.str);
       goto err_lock;
     }
+
+    /* Open view */
+    if (mysql_make_view(thd, share, table_list, false))
+      goto err_lock;
+
     /*
       This table is a view. Validate its metadata version: in particular,
       that it was a view when the statement was prepared.
@@ -1913,10 +1918,6 @@ retry_share:
     if (check_and_update_table_version(thd, table_list, share))
       goto err_lock;
 
-    /* Open view */
-    if (mysql_make_view(thd, share, table_list, false))
-      goto err_lock;
-
 
     /* TODO: Don't free this */
     tdc_release_share(share);
@@ -2721,7 +2722,7 @@ static bool inject_reprepare(THD *thd)
 
   @sa Execute_observer
   @sa check_prepared_statement() to see cases when an observer is installed
-  @sa TABLE_LIST::is_table_ref_id_equal()
+  @sa TABLE_LIST::is_the_same_definition()
   @sa TABLE_SHARE::get_table_ref_id()
 
   @param[in]      thd         used to report errors
@@ -2738,7 +2739,7 @@ static bool
 check_and_update_table_version(THD *thd,
                                TABLE_LIST *tables, TABLE_SHARE *table_share)
 {
-  if (! tables->is_table_ref_id_equal(table_share))
+  if (! tables->is_the_same_definition(thd, table_share))
   {
     if (thd->m_reprepare_observer &&
         thd->m_reprepare_observer->report_error(thd))
@@ -2844,7 +2845,9 @@ bool tdc_open_view(THD *thd, TABLE_LIST *table_list, uint flags)
 
   DBUG_ASSERT(share->is_view);
 
-  if (flags & CHECK_METADATA_VERSION)
+  err= mysql_make_view(thd, share, table_list, (flags & OPEN_VIEW_NO_PARSE));
+
+  if (!err && (flags & CHECK_METADATA_VERSION))
   {
     /*
       Check TABLE_SHARE-version of view only if we have been instructed to do
@@ -2859,7 +2862,6 @@ bool tdc_open_view(THD *thd, TABLE_LIST *table_list, uint flags)
       goto ret;
   }
 
-  err= mysql_make_view(thd, share, table_list, (flags & OPEN_VIEW_NO_PARSE));
 ret:
   tdc_release_share(share);
 
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 733f399a32c..043fb6f24d8 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -3879,6 +3879,7 @@ Statement::Statement(LEX *lex_arg, MEM_ROOT *mem_root_arg,
   id(id_arg),
   column_usage(MARK_COLUMNS_READ),
   lex(lex_arg),
+  hr_prepare_time({0}),
   db(null_clex_str)
 {
   name= null_clex_str;
@@ -3897,6 +3898,7 @@ void Statement::set_statement(Statement *stmt)
   column_usage=   stmt->column_usage;
   lex=            stmt->lex;
   query_string=   stmt->query_string;
+  hr_prepare_time=    stmt->hr_prepare_time;
 }
 
 
diff --git a/sql/sql_class.h b/sql/sql_class.h
index d3e2b72b12d..7ef5e19a45d 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -1122,6 +1122,7 @@ public:
 
   LEX_CSTRING name; /* name for named prepared statements */
   LEX *lex;                                     // parse tree descriptor
+  my_hrtime_t hr_prepare_time; // time of preparation in microseconds
   /*
     Points to the query associated with this statement. It's const, but
     we need to declare it char * because all table handlers are written
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 71dc85c3100..47024e7c219 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -4311,6 +4311,8 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len)
     if (thd->spcont == NULL)
       general_log_write(thd, COM_STMT_PREPARE, query(), query_length());
   }
+  // The same format as for triggers to compare
+  hr_prepare_time= my_hrtime();
   DBUG_RETURN(error);
 }
 
@@ -4404,8 +4406,8 @@ Prepared_statement::execute_loop(String *expanded_query,
                                  uchar *packet_end)
 {
   Reprepare_observer reprepare_observer;
-  bool error;
   int reprepare_attempt= 0;
+  bool error;
   iterations= FALSE;
 
   /*
diff --git a/sql/sql_show.cc b/sql/sql_show.cc
index eaed36a3506..bae712a407d 100644
--- a/sql/sql_show.cc
+++ b/sql/sql_show.cc
@@ -7117,13 +7117,15 @@ static bool store_trigger(THD *thd, Trigger *trigger,
   table->field[14]->store(STRING_WITH_LEN("OLD"), cs);
   table->field[15]->store(STRING_WITH_LEN("NEW"), cs);
 
-  if (trigger->create_time)
+  if (trigger->hr_create_time.val)
   {
+    /* timestamp is in microseconds */
     table->field[16]->set_notnull();
-    thd->variables.time_zone->gmt_sec_to_TIME(&timestamp,
-                                              (my_time_t)(trigger->create_time/100));
-    /* timestamp is with 6 digits */
-    timestamp.second_part= (trigger->create_time % 100) * 10000;
+    thd->variables.time_zone->
+      gmt_sec_to_TIME(&timestamp,
+                      (my_time_t)
+                      hrtime_to_time(trigger->hr_create_time));
+    timestamp.second_part= hrtime_sec_part(trigger->hr_create_time);
     ((Field_temporal_with_date*) table->field[16])->store_time_dec(&timestamp,
                                                                    2);
   }
@@ -10294,12 +10296,14 @@ static bool show_create_trigger_impl(THD *thd, Trigger *trigger)
            trigger->db_cl_name.length,
            system_charset_info);
 
-  if (trigger->create_time)
+  if (trigger->hr_create_time.val)
   {
     MYSQL_TIME timestamp;
-    thd->variables.time_zone->gmt_sec_to_TIME(&timestamp,
-                                              (my_time_t)(trigger->create_time/100));
-    timestamp.second_part= (trigger->create_time % 100) * 10000;
+    thd->variables.time_zone->
+      gmt_sec_to_TIME(&timestamp,
+                      (my_time_t)
+                      hrtime_to_time(trigger->hr_create_time));
+    timestamp.second_part= hrtime_sec_part(trigger->hr_create_time);
     p->store(&timestamp, 2);
   }
   else
diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index 247055d397c..375b2e12d65 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -37,6 +37,8 @@
 #ifdef WITH_WSREP
 #include "debug_sync.h"
 #endif /* WITH_WSREP */
+#include <my_time.h>
+#include <mysql_time.h>
 
 LEX_CSTRING *make_lex_string(LEX_CSTRING *lex_str,
                              const char* str, size_t length,
@@ -212,7 +214,7 @@ static File_option triggers_file_parameters[]=
   },
   {
     { STRING_WITH_LEN("created") },
-    my_offsetof(class Table_triggers_list, create_times),
+    my_offsetof(class Table_triggers_list, hr_create_times),
     FILE_OPTIONS_ULLLIST
   },
   { { 0, 0 }, 0, FILE_OPTIONS_STRING }
@@ -896,6 +898,10 @@ bool Table_triggers_list::create_trigger(THD *thd, TABLE_LIST *tables,
   if (!(trigger= new (&table->mem_root) Trigger(this, 0)))
     goto err_without_cleanup;
 
+  /* Time with in microseconds */
+  trigger->hr_create_time= make_hr_time(thd->query_start(),
+                                        thd->query_start_sec_part());
+
   /* Create trigger_name.TRN file to ensure trigger name is unique */
   if (sql_create_definition_file(NULL, &trigname_file, &trigname_file_type,
                                  (uchar*)&trigname, trigname_file_parameters))
@@ -904,8 +910,6 @@ bool Table_triggers_list::create_trigger(THD *thd, TABLE_LIST *tables,
   /* Populate the trigger object */
 
   trigger->sql_mode= thd->variables.sql_mode;
-  /* Time with 2 decimals, like in MySQL 5.7 */
-  trigger->create_time= ((ulonglong) thd->query_start())*100 + thd->query_start_sec_part()/10000;
   build_trig_stmt_query(thd, tables, stmt_query, &trigger_definition,
                         &trigger->definer, trg_definer_holder);
 
@@ -973,7 +977,7 @@ void Table_triggers_list::empty_lists()
   client_cs_names.empty();
   connection_cl_names.empty();
   db_cl_names.empty();
-  create_times.empty();
+  hr_create_times.empty();
 }
 
 
@@ -1009,7 +1013,7 @@ bool Trigger::add_to_file_list(void* param_arg)
       base->client_cs_names.push_back(&client_cs_name, mem_root) ||
       base->connection_cl_names.push_back(&connection_cl_name, mem_root) ||
       base->db_cl_names.push_back(&db_cl_name, mem_root) ||
-      base->create_times.push_back(&create_time, mem_root))
+      base->hr_create_times.push_back(&hr_create_time.val, mem_root))
     return 1;
   return 0;
 }
@@ -1391,7 +1395,8 @@ bool Table_triggers_list::check_n_load(THD *thd, const LEX_CSTRING *db,
       List_iterator_fast<LEX_CSTRING> it_client_cs_name(trigger_list->client_cs_names);
       List_iterator_fast<LEX_CSTRING> it_connection_cl_name(trigger_list->connection_cl_names);
       List_iterator_fast<LEX_CSTRING> it_db_cl_name(trigger_list->db_cl_names);
-      List_iterator_fast<ulonglong> it_create_times(trigger_list->create_times);
+      List_iterator_fast<ulonglong>
+        it_create_times(trigger_list->hr_create_times);
       LEX *old_lex= thd->lex;
       LEX lex;
       sp_rcontext *save_spcont= thd->spcont;
@@ -1477,7 +1482,14 @@ bool Table_triggers_list::check_n_load(THD *thd, const LEX_CSTRING *db,
 
         trigger->sql_mode= sql_mode;
         trigger->definition= *trg_create_str;
-        trigger->create_time= trg_create_time ? *trg_create_time : 0;
+        trigger->hr_create_time=
+          my_hrtime_t({trg_create_time ? *trg_create_time : 0});
+        /*
+          Fix time if in 100th of second (comparison with max uint * 100
+          (max possible timestamp in the old format))
+        */
+        if (trigger->hr_create_time.val < 429496729400ULL)
+          trigger->hr_create_time.val*= 10000;
         trigger->name= sp ? sp->m_name : empty_clex_str;
         trigger->on_table_name.str= (char*) lex.raw_trg_on_table_name_begin;
         trigger->on_table_name.length= (lex.raw_trg_on_table_name_end -
diff --git a/sql/sql_trigger.h b/sql/sql_trigger.h
index ae3d1738b16..f906fa0d1a8 100644
--- a/sql/sql_trigger.h
+++ b/sql/sql_trigger.h
@@ -115,7 +115,7 @@ public:
   GRANT_INFO subject_table_grants;
   sql_mode_t sql_mode;
   /* Store create time. Can't be mysql_time_t as this holds also sub seconds */
-  ulonglong create_time;
+  my_hrtime_t hr_create_time; // Create time timestamp in microseconds
   trg_event_type event;
   trg_action_time_type action_time;
   uint action_order;
@@ -198,7 +198,7 @@ public:
   */
   List<ulonglong> definition_modes_list;
   /** Create times for triggers */
-  List<ulonglong> create_times;
+  List<ulonglong> hr_create_times;
 
   List<LEX_CSTRING>  definers_list;
 
diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index b0b4b075046..68a8410f559 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -786,7 +786,7 @@ static File_option view_parameters[]=
   my_offsetof(TABLE_LIST, with_check),
   FILE_OPTIONS_ULONGLONG},
  {{ STRING_WITH_LEN("timestamp")},
-  my_offsetof(TABLE_LIST, timestamp),
+  my_offsetof(TABLE_LIST, hr_timestamp),
   FILE_OPTIONS_TIMESTAMP},
  {{ STRING_WITH_LEN("create-version")},
   my_offsetof(TABLE_LIST, file_version),
@@ -810,6 +810,15 @@ static File_option view_parameters[]=
   FILE_OPTIONS_STRING}
 };
 
+
+static File_option view_timestamp_parameters[]=
+{
+
+ {{ C_STRING_WITH_LEN("timestamp")}, 0, FILE_OPTIONS_TIMESTAMP},
+ {{NullS, 0}, 0, FILE_OPTIONS_STRING}
+};
+
+
 static LEX_CSTRING view_file_type[]= {{STRING_WITH_LEN("VIEW") }};
 
 
@@ -827,8 +836,8 @@ int mariadb_fix_view(THD *thd, TABLE_LIST *view, bool wrong_checksum,
                      &path, path_buff, sizeof(path_buff),
                      &file, view);
   /* init timestamp */
-  if (!view->timestamp.str)
-    view->timestamp.str= view->timestamp_buffer;
+  if (!view->hr_timestamp.str)
+    view->hr_timestamp.str= view->timestamp_buffer;
 
   if (swap_alg && view->algorithm != VIEW_ALGORITHM_UNDEFINED)
   {
@@ -1029,8 +1038,8 @@ loop_out:
                      &path, path_buff, sizeof(path_buff),
                      &file, view);
   /* init timestamp */
-  if (!view->timestamp.str)
-    view->timestamp.str= view->timestamp_buffer;
+  if (!view->hr_timestamp.str)
+    view->hr_timestamp.str= view->timestamp_buffer;
 
   /* check old .frm */
   {
@@ -1155,7 +1164,32 @@ err:
   DBUG_RETURN(error);
 }
 
+/**
+  Reads view definition "version"
 
+  @param[in]  share               Share object of view
+
+  @return true on error, otherwise false
+*/
+
+bool mariadb_view_version_get(TABLE_SHARE *share)
+{
+  DBUG_ASSERT(share->is_view);
+
+  if (!(share->tabledef_version.str=
+        (uchar*) alloc_root(&share->mem_root,
+                            MICROSECOND_TIMESTAMP_BUFFER_SIZE)))
+    return TRUE;
+  share->tabledef_version.length= 0; // safety if the drfinition file is brocken
+
+  DBUG_ASSERT(share->view_def != NULL);
+  if (share->view_def->parse((uchar *) &share->tabledef_version, NULL,
+                             view_timestamp_parameters, 1,
+                             &file_parser_dummy_hook))
+    return TRUE;
+  DBUG_ASSERT(share->tabledef_version.length == MICROSECOND_TIMESTAMP_BUFFER_SIZE-1);
+  return FALSE;
+}
 
 /**
   read VIEW .frm and create structures
@@ -1217,6 +1251,10 @@ bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table,
     mysql_derived_reinit(thd, NULL, table);
 
     DEBUG_SYNC(thd, "after_cached_view_opened");
+    if (!share->tabledef_version.length)
+    {
+      mariadb_view_version_get(share);
+    }
     DBUG_RETURN(0);
   }
 
@@ -1253,8 +1291,8 @@ bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table,
   arena= thd->activate_stmt_arena_if_needed(&backup);
 
   /* init timestamp */
-  if (!table->timestamp.str)
-    table->timestamp.str= table->timestamp_buffer;
+  if (!table->hr_timestamp.str)
+    table->hr_timestamp.str= table->timestamp_buffer;
   /* prepare default values for old format */
   table->view_suid= TRUE;
   table->definer.user.str= table->definer.host.str= 0;
@@ -1270,6 +1308,19 @@ bool mysql_make_view(THD *thd, TABLE_SHARE *share, TABLE_LIST *table,
                                       required_view_parameters,
                                       &file_parser_dummy_hook)))
     goto end;
+  if (!share->tabledef_version.length)
+  {
+    share->tabledef_version.str= (const uchar *)
+                                 memdup_root(&share->mem_root,
+                                             (const void *)
+                                             table->hr_timestamp.str,
+                                             (share->tabledef_version.length=
+                                              table->hr_timestamp.length));
+  }
+  if (!table->tabledef_version.length)
+  {
+    table->set_view_def_version(&table->hr_timestamp);
+  }
 
   /*
     check old format view .frm
@@ -2200,7 +2251,7 @@ mysql_rename_view(THD *thd,
       object for it.
     */
     view_def.reset();
-    view_def.timestamp.str= view_def.timestamp_buffer;
+    view_def.hr_timestamp.str= view_def.timestamp_buffer;
     view_def.view_suid= TRUE;
 
     /* get view definition and source */
diff --git a/sql/table.cc b/sql/table.cc
index 506195127b2..5d91026963a 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -8861,6 +8861,73 @@ bool TABLE_LIST::is_with_table()
   return derived && derived->with_element;
 }
 
+
+/**
+  Check if the definition are the same.
+
+  If versions do not match it check definitions (with checking and setting
+  trigger definition versions (times)
+
+  @param[in]  view                TABLE_LIST of the view
+  @param[in]  share               Share object of view
+
+  @return false on error or different definitions.
+
+  @sa check_and_update_table_version()
+*/
+
+bool TABLE_LIST::is_the_same_definition(THD* thd, TABLE_SHARE *s)
+{
+  enum enum_table_ref_type tp= s->get_table_ref_type();
+  if (m_table_ref_type == tp)
+  {
+    /*
+      Cache have not changed which means that definition was not changed
+      including triggers
+    */
+    if (m_table_ref_version == s->get_table_ref_version())
+      return TRUE;
+
+    /*
+      If cache changed then check content version
+    */
+    if ((tabledef_version.length &&
+         tabledef_version.length == s->tabledef_version.length &&
+         memcmp(tabledef_version.str, s->tabledef_version.str,
+                tabledef_version.length) == 0))
+    {
+      // Definition have not changed, let's check if triggers changed.
+      if (table && table->triggers)
+      {
+
+        my_hrtime_t hr_stmt_prepare= thd->hr_prepare_time;
+        if (hr_stmt_prepare.val)
+          for(uint i= 0; i < TRG_EVENT_MAX; i++)
+            for (uint j= 0; j < TRG_ACTION_MAX; j++)
+            {
+              Trigger *tr=
+                table->triggers->get_trigger((trg_event_type)i,
+                                             (trg_action_time_type)j);
+              if (tr)
+                if (hr_stmt_prepare.val <= tr->hr_create_time.val)
+                {
+                  set_tabledef_version(s);
+                  return FALSE;
+                }
+            }
+      }
+      set_table_id(s);
+      return TRUE;
+    }
+    else
+      tabledef_version.length= 0;
+  }
+  else
+    set_tabledef_version(s);
+  return FALSE;
+}
+
+
 uint TABLE_SHARE::actual_n_key_parts(THD *thd)
 {
   return use_ext_keys &&
diff --git a/sql/table.h b/sql/table.h
index 6036afd3750..1eb09f119ed 100644
--- a/sql/table.h
+++ b/sql/table.h
@@ -32,8 +32,18 @@
 #include "filesort_utils.h"
 #include "parse_file.h"
 
-/* buffer for timestamp (19+1) */
-#define VIEW_TIME_STAMP_BUFFER_SIZE (PARSE_FILE_TIMESTAMPLENGTH + 1)
+/*
+  Buffer for unix timestamp in microseconds:
+  9,223,372,036,854,775,807 (signed int64 maximal value)
+  1 234 567 890 123 456 789
+
+  Note: we can use unsigned for calculation, but practically they
+  are the same by probability to overflow them (signed int64 in
+  microseconds is enough for almost 3e5 years) and signed allow to
+  avoid increasing the buffer (the old buffer for human readable
+  date was 19+1).
+*/
+#define MICROSECOND_TIMESTAMP_BUFFER_SIZE (19 + 1)
 
 /* Structs that defines the TABLE */
 
@@ -1028,7 +1038,7 @@ struct TABLE_SHARE
    with a base table, a base table is replaced with a temporary
    table and so on.
 
-   @sa TABLE_LIST::is_table_ref_id_equal()
+   @sa TABLE_LIST::is_the_same_definition()
   */
   ulong get_table_ref_version() const
   {
@@ -2369,6 +2379,12 @@ struct TABLE_LIST
     to view with SQL SECURITY DEFINER)
   */
   Security_context *security_ctx;
+  uchar tabledef_version_buf[MY_UUID_SIZE >
+                               MICROSECOND_TIMESTAMP_BUFFER_SIZE-1 ?
+                             MY_UUID_SIZE + 1 :
+                             MICROSECOND_TIMESTAMP_BUFFER_SIZE];
+  LEX_CUSTRING tabledef_version;
+
   /*
     This view security context (non-zero only for views with
     SQL SECURITY DEFINER)
@@ -2382,7 +2398,7 @@ struct TABLE_LIST
   LEX_CSTRING	source;			/* source of CREATE VIEW */
   LEX_CSTRING	view_db;		/* saved view database */
   LEX_CSTRING	view_name;		/* saved view name */
-  LEX_STRING	timestamp;		/* GMT time stamp of last operation */
+  LEX_STRING	hr_timestamp;           /* time stamp of last operation */
   LEX_USER      definer;                /* definer of view */
   ulonglong	file_version;		/* version of file's field set */
   ulonglong	mariadb_version;	/* version of server on creation */
@@ -2465,7 +2481,7 @@ struct TABLE_LIST
   /* TABLE_TYPE_UNKNOWN if any type is acceptable */
   Table_type    required_type;
   handlerton	*db_type;		/* table_type for handler */
-  char		timestamp_buffer[VIEW_TIME_STAMP_BUFFER_SIZE];
+  char		timestamp_buffer[MICROSECOND_TIMESTAMP_BUFFER_SIZE];
   /*
     This TABLE_LIST object is just placeholder for prelocking, it will be
     used for implicit LOCK TABLES only and won't be used in real statement.
@@ -2657,19 +2673,7 @@ struct TABLE_LIST
   */
   bool process_index_hints(TABLE *table);
 
-  /**
-    Compare the version of metadata from the previous execution
-    (if any) with values obtained from the current table
-    definition cache element.
-
-    @sa check_and_update_table_version()
-  */
-  inline bool is_table_ref_id_equal(TABLE_SHARE *s) const
-  {
-    return (m_table_ref_type == s->get_table_ref_type() &&
-            m_table_ref_version == s->get_table_ref_version());
-  }
-
+  bool is_the_same_definition(THD *thd, TABLE_SHARE *s);
   /**
     Record the value of metadata version of the corresponding
     table definition cache element in this parse tree node.
@@ -2686,6 +2690,26 @@ struct TABLE_LIST
     m_table_ref_version= table_ref_version_arg;
   }
 
+  void set_table_id(TABLE_SHARE *s)
+  {
+    set_table_ref_id(s);
+    set_tabledef_version(s);
+  }
+
+  void set_tabledef_version(TABLE_SHARE *s)
+  {
+    if (!tabledef_version.length && s->tabledef_version.length)
+    {
+      DBUG_ASSERT(s->tabledef_version.length <
+                  sizeof(tabledef_version_buf));
+      tabledef_version.str= tabledef_version_buf;
+      memcpy(tabledef_version_buf, s->tabledef_version.str,
+             (tabledef_version.length= s->tabledef_version.length));
+      // safety
+      tabledef_version_buf[tabledef_version.length]= 0;
+    }
+  }
+
   /* Set of functions returning/setting state of a derived table/view. */
   inline bool is_non_derived()
   {
@@ -2814,6 +2838,12 @@ struct TABLE_LIST
     }
   }
 
+  inline void set_view_def_version(LEX_STRING *version)
+  {
+    m_table_ref_type= TABLE_REF_VIEW;
+    tabledef_version.str= (const uchar *) version->str;
+    tabledef_version.length= version->length;
+  }
 private:
   bool prep_check_option(THD *thd, uint8 check_opt_type);
   bool prep_where(THD *thd, Item **conds, bool no_where_clause);