Remove trx_mod_tables_t::vers_by_trx

Only invoke set_versioned() on trx_id versioned tables.

dict_table_t::versioned_by_id(): New accessor, to determine if
a table is system versioned by transaction ID.

storage/innobase/handler/ha_innodb.cc

@@ -3636,8 +3636,8 @@ static ulonglong innodb_prepare_commit_versioned(THD* thd, ulonglong *trx_id)
 		for (trx_mod_tables_t::const_iterator t
 			     = trx->mod_tables.begin();
 		     t != trx->mod_tables.end(); t++) {
-			if (t->second.is_trx_versioned()) {
-				DBUG_ASSERT(t->first->versioned());
+			if (t->second.is_versioned()) {
+				DBUG_ASSERT(t->first->versioned_by_id());
 				DBUG_ASSERT(trx->rsegs.m_redo.rseg);
 
 				mutex_enter(&trx_sys.mutex);

storage/innobase/include/dict0mem.h

@@ -1543,6 +1543,10 @@ struct dict_table_t {
 	void add_to_cache();
 
 	bool versioned() const { return vers_start || vers_end; }
+	bool versioned_by_id() const
+	{
+		return vers_start && cols[vers_start].mtype == DATA_INT;
+	}
 
 	void inc_fk_checks()
 	{

storage/innobase/include/trx0trx.h

 /*****************************************************************************
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2017, MariaDB Corporation.
+Copyright (c) 2015, 2018, MariaDB Corporation.
 
 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 the Free Software
@@ -699,7 +699,6 @@ class trx_mod_table_time_t
 	undo_no_t	first;
 	/** First modification of a system versioned column */
 	undo_no_t	first_versioned;
-	bool		vers_by_trx;
 
 	/** Magic value signifying that a system versioned column of a
 	table was never modified in a transaction. */
@@ -709,8 +708,7 @@ class trx_mod_table_time_t
 	/** Constructor
 	@param[in]	rows	number of modified rows so far */
 	trx_mod_table_time_t(undo_no_t rows)
-		: first(rows), first_versioned(UNVERSIONED),
-		vers_by_trx(false) {}
+		: first(rows), first_versioned(UNVERSIONED) {}
 
 #ifdef UNIV_DEBUG
 	/** Validation
@@ -723,18 +721,13 @@ class trx_mod_table_time_t
 #endif /* UNIV_DEBUG */
 	/** @return if versioned columns were modified */
 	bool is_versioned() const { return first_versioned != UNVERSIONED; }
-	bool is_trx_versioned() const
-	{
-		return is_versioned() && vers_by_trx;
-	}
 
 	/** After writing an undo log record, set is_versioned() if needed
 	@param[in]	rows	number of modified rows so far */
-	void set_versioned(undo_no_t rows, bool by_trx_id)
+	void set_versioned(undo_no_t rows)
 	{
 		ut_ad(!is_versioned());
 		first_versioned = rows;
-		vers_by_trx = by_trx_id;
 		ut_ad(valid());
 	}
 

storage/innobase/row/row0merge.cc

 /*****************************************************************************
 
 Copyright (c) 2005, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2014, 2017, MariaDB Corporation.
+Copyright (c) 2014, 2018, MariaDB Corporation.
 
 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 the Free Software
@@ -2881,7 +2881,7 @@ row_merge_read_clustered_index(
 				.insert(trx_mod_tables_t::value_type(
 					const_cast<dict_table_t*>(new_table), 0))
 				.first->second;
-		time.set_versioned(0, true);
+		time.set_versioned(0);
 	}
 
 	trx->op_info = "";

storage/innobase/trx/trx0rec.cc

@@ -2114,14 +2114,11 @@ trx_undo_report_row_operation(
 				ut_ad(time.valid(limit));
 
 				if (!time.is_versioned()
-				    && index->table->versioned()
+				    && index->table->versioned_by_id()
 				    && (!rec /* INSERT */
 					|| !update /* DELETE */
-					|| update->affects_versioned()))
-				{
-					dict_col_t &col = index->table->cols[index->table->vers_start];
-					bool by_trx_id = col.mtype == DATA_INT;
-					time.set_versioned(limit, by_trx_id);
+					|| update->affects_versioned())) {
+					time.set_versioned(limit);
 				}
 			}