IB: remove alloc on update

Author: midenok

storage/innobase/handler/ha_innodb.cc

@@ -9171,14 +9171,11 @@ ha_innobase::update_row(
 	m_prebuilt->upd_node->is_delete = NO_DELETE;
 
 	{
-		const bool	vers_set_fields
-			= m_prebuilt->versioned_write
+		const bool vers_set_fields = m_prebuilt->versioned_write
 			&& m_prebuilt->upd_node->update->affects_versioned();
-		const bool	vers_ins_row
-			= vers_set_fields
+		const bool vers_ins_row = vers_set_fields
 			&& (table->s->vtmd
-			    || thd_sql_command(m_user_thd)
-			    != SQLCOM_ALTER_TABLE);
+			    || thd_sql_command(m_user_thd) != SQLCOM_ALTER_TABLE);
 
 		if (vers_set_fields && !vers_ins_row)
 			m_prebuilt->upd_node->is_delete = VERSIONED_DELETE;

storage/innobase/include/row0upd.h

@@ -464,6 +464,7 @@ struct upd_t{
 					virtual column update now */
 	ulint		n_fields;	/*!< number of update fields */
 	upd_field_t*	fields;		/*!< array of update fields */
+	byte		vers_sys_value[8]; /*!< buffer for updating system fields */
 
 	/** Append an update field to the end of array
 	@param[in]	field	an update field */

storage/innobase/row/row0mysql.cc

@@ -2004,7 +2004,6 @@ row_update_for_mysql(row_prebuilt_t* prebuilt)
 	ut_ad(!prebuilt->versioned_write || node->table->versioned());
 
 	bool vers_set_fields = prebuilt->versioned_write
-		&& node->table->versioned()
 		&& (node->is_delete ? node->is_delete == VERSIONED_DELETE
 		    : node->update->affects_versioned());
 run_again:
@@ -2038,11 +2037,9 @@ row_update_for_mysql(row_prebuilt_t* prebuilt)
 		ufield->orig_len = 0;
 		ufield->exp = NULL;
 
-		static const ulint fsize = sizeof(trx_id_t);
-		byte* buf = static_cast<byte*>(mem_heap_alloc(node->update->heap, fsize));
-		mach_write_to_8(buf, trx->id);
+		mach_write_to_8(node->update->vers_sys_value, trx->id);
 		dfield_t* dfield = &ufield->new_val;
-		dfield_set_data(dfield, buf, fsize);
+		dfield_set_data(dfield, node->update->vers_sys_value, 8);
 		dict_col_copy_type(col, &dfield->type);
 
 		uvect->n_fields++;