text: /*****************************************************************************
  
  Copyright (c) 1996, 2018, Oracle and/or its affiliates. All Rights Reserved.
  
  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
  Foundation; version 2 of the License.
  
  This program is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  
  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
  
  *****************************************************************************/
  
  /**************************************************//**
  @file row/row0upd.cc
  Update of a row
  
  Created 12/27/1996 Heikki Tuuri
  *******************************************************/
  
  #include "ha_prototypes.h"
  
  #include "row0upd.h"
  
  #ifdef UNIV_NONINL
  #include "row0upd.ic"
  #endif
  
  #include "dict0dict.h"
  #include "trx0undo.h"
  #include "rem0rec.h"
  #ifndef UNIV_HOTBACKUP
  #include "dict0boot.h"
  #include "dict0crea.h"
  #include "mach0data.h"
  #include "btr0btr.h"
  #include "btr0cur.h"
  #include "que0que.h"
  #include "row0ext.h"
  #include "row0ins.h"
  #include "row0log.h"
  #include "row0row.h"
  #include "row0sel.h"
  #include "rem0cmp.h"
  #include "lock0lock.h"
  #include "log0log.h"
  #include "pars0sym.h"
  #include "eval0eval.h"
  #include "buf0lru.h"
  #include "trx0rec.h"
  #include "fts0fts.h"
  #include "fts0types.h"
  #include <algorithm>
  
  /* What kind of latch and lock can we assume when the control comes to
     -------------------------------------------------------------------
  an update node?
  --------------
  Efficiency of massive updates would require keeping an x-latch on a
  clustered index page through many updates, and not setting an explicit
  x-lock on clustered index records, as they anyway will get an implicit
  x-lock when they are updated. A problem is that the read nodes in the
  graph should know that they must keep the latch when passing the control
  up to the update node, and not set any record lock on the record which
  will be updated. Another problem occurs if the execution is stopped,
  as the kernel switches to another query thread, or the transaction must
  wait for a lock. Then we should be able to release the latch and, maybe,
  acquire an explicit x-lock on the record.
  	Because this seems too complicated, we conclude that the less
  efficient solution of releasing all the latches when the control is
  transferred to another node, and acquiring explicit x-locks, is better. */
  
  /* How is a delete performed? If there is a delete without an
  explicit cursor, i.e., a searched delete, there are at least
  two different situations:
  the implicit select cursor may run on (1) the clustered index or
  on (2) a secondary index. The delete is performed by setting
  the delete bit in the record and substituting the id of the
  deleting transaction for the original trx id, and substituting a
  new roll ptr for previous roll ptr. The old trx id and roll ptr
  are saved in the undo log record. Thus, no physical changes occur
  in the index tree structure at the time of the delete. Only
  when the undo log is purged, the index records will be physically
  deleted from the index trees.
  
  The query graph executing a searched delete would consist of
  a delete node which has as a subtree a select subgraph.
  The select subgraph should return a (persistent) cursor
  in the clustered index, placed on page which is x-latched.
  The delete node should look for all secondary index records for
  this clustered index entry and mark them as deleted. When is
  the x-latch freed? The most efficient way for performing a
  searched delete is obviously to keep the x-latch for several
  steps of query graph execution. */
  
  /*************************************************************************
  IMPORTANT NOTE: Any operation that generates redo MUST check that there
  is enough space in the redo log before for that operation. This is
  done by calling log_free_check(). The reason for checking the
  availability of the redo log space before the start of the operation is
  that we MUST not hold any synchonization objects when performing the
  check.
  If you make a change in this module make sure that no codepath is
  introduced where a call to log_free_check() is bypassed. */
  
  /***********************************************************//**
  Checks if an update vector changes some of the first ordering fields of an
  index record. This is only used in foreign key checks and we can assume
  that index does not contain column prefixes.
  @return TRUE if changes */
  static
  ibool
  row_upd_changes_first_fields_binary(
  /*================================*/
  	dtuple_t*	entry,	/*!< in: old value of index entry */
  	dict_index_t*	index,	/*!< in: index of entry */
  	const upd_t*	update,	/*!< in: update vector for the row */
  	ulint		n);	/*!< in: how many first fields to check */
  
  
  /*********************************************************************//**
  Checks if index currently is mentioned as a referenced index in a foreign
  key constraint.
  
  NOTE that since we do not hold dict_operation_lock when leaving the
  function, it may be that the referencing table has been dropped when
  we leave this function: this function is only for heuristic use!
  
  @return TRUE if referenced */
  static
  ibool
  row_upd_index_is_referenced(
  /*========================*/
  	dict_index_t*	index,	/*!< in: index */
  	trx_t*		trx)	/*!< in: transaction */
  {
  	dict_table_t*	table		= index->table;
  	ibool		froze_data_dict	= FALSE;
  	ibool		is_referenced	= FALSE;
  
  	if (table->referenced_set.empty()) {
  		return(FALSE);
  	}
  
  	if (trx->dict_operation_lock_mode == 0) {
  		row_mysql_freeze_data_dictionary(trx);
  		froze_data_dict = TRUE;
  	}
  
  	dict_foreign_set::iterator	it
  		= std::find_if(table->referenced_set.begin(),
  			       table->referenced_set.end(),
  			       dict_foreign_with_index(index));
  
  	is_referenced = (it != table->referenced_set.end());
  
  	if (froze_data_dict) {
  		row_mysql_unfreeze_data_dictionary(trx);
  	}
  
  	return(is_referenced);
  }
  
  /*********************************************************************//**
  Checks if possible foreign key constraints hold after a delete of the record
  under pcur.
  
  NOTE that this function will temporarily commit mtr and lose the
  pcur position!
  
  @return DB_SUCCESS or an error code */
  static MY_ATTRIBUTE((warn_unused_result))
  dberr_t
  row_upd_check_references_constraints(
  /*=================================*/
  	upd_node_t*	node,	/*!< in: row update node */
  	btr_pcur_t*	pcur,	/*!< in: cursor positioned on a record; NOTE: the
  				cursor position is lost in this function! */
  	dict_table_t*	table,	/*!< in: table in question */
  	dict_index_t*	index,	/*!< in: index of the cursor */
  	ulint*		offsets,/*!< in/out: rec_get_offsets(pcur.rec, index) */
  	que_thr_t*	thr,	/*!< in: query thread */
  	mtr_t*		mtr)	/*!< in: mtr */
  {
  	dict_foreign_t*	foreign;
  	mem_heap_t*	heap;
  	dtuple_t*	entry;
  	trx_t*		trx;
  	const rec_t*	rec;
  	ulint		n_ext;
  	dberr_t		err;
  	ibool		got_s_lock	= FALSE;
  
  	DBUG_ENTER("row_upd_check_references_constraints");
  
  	if (table->referenced_set.empty()) {
  		DBUG_RETURN(DB_SUCCESS);
  	}
  
  	trx = thr_get_trx(thr);
  
  	rec = btr_pcur_get_rec(pcur);
  	ut_ad(rec_offs_validate(rec, index, offsets));
  
  	heap = mem_heap_create(500);
  
  	entry = row_rec_to_index_entry(rec, index, offsets, &n_ext, heap);
  
  	mtr_commit(mtr);
  
  	DEBUG_SYNC_C("foreign_constraint_check_for_update");
  
  	mtr_start(mtr);
  
  	if (trx->dict_operation_lock_mode == 0) {
  		got_s_lock = TRUE;
  
  		row_mysql_freeze_data_dictionary(trx);
  	}
  
  	DEBUG_SYNC_C_IF_THD(thr_get_trx(thr)->mysql_thd,
  			    "foreign_constraint_check_for_insert");
  
  	for (dict_foreign_set::iterator it = table->referenced_set.begin();
  	     it != table->referenced_set.end();
  	     ++it) {
  
  		foreign = *it;
  
  		/* Note that we may have an update which updates the index
  		record, but does NOT update the first fields which are
  		referenced in a foreign key constraint. Then the update does
  		NOT break the constraint. */
  
  		if (foreign->referenced_index == index
  		    && (node->is_delete
  			|| row_upd_changes_first_fields_binary(
  				entry, index, node->update,
  				foreign->n_fields))) {
  			dict_table_t*	foreign_table = foreign->foreign_table;
  
  			dict_table_t*	ref_table = NULL;
  
  			if (foreign_table == NULL) {
  
  				ref_table = dict_table_open_on_name(
  					foreign->foreign_table_name_lookup,
  					FALSE, FALSE, DICT_ERR_IGNORE_NONE);
  			}
  
  			/** dict_operation_lock is held both here and by truncate operations.
  			If a truncate is in process by another concurrent thread,
  			there can be 2 conditions possible:
  			1) row_truncate_table_for_mysql() is not yet called.
  			2) Truncate releases dict_operation_lock
  			during eviction of pages from buffer pool
  			for a file-per-table tablespace.
  
  			In case of (1), truncate will wait for FK operation
  			to complete.
  			In case of (2), truncate will be rolled forward even
  			if it is interrupted. So if the foreign table is
  			undergoing a truncate, ignore the FK check. */
  
  			if (foreign_table != NULL &&
  			   (dict_table_is_discarded(foreign_table)
  			    || fil_space_is_being_truncated(
  						foreign_table->space))) {
  				continue;
  			}
  
  			/* NOTE that if the thread ends up waiting for a lock
  			we will release dict_operation_lock temporarily!
  			But the counter on the table protects 'foreign' from
  			being dropped while the check is running. */
  
  
                          if (foreign_table) {
  				os_atomic_increment_ulint(&foreign_table->n_foreign_key_checks_running, 1);
  			}
  
  			err = row_ins_check_foreign_constraint(
  				FALSE, foreign, table, entry, thr);
  
                          if (foreign_table) {
  				os_atomic_decrement_ulint(&foreign_table->n_foreign_key_checks_running, 1);
  			}
  			if (ref_table != NULL) {
  				dict_table_close(ref_table, FALSE, FALSE);
  			}
  
  			if (err != DB_SUCCESS) {
  				goto func_exit;
  			}
  		}
  	}
  
  	err = DB_SUCCESS;
  
  func_exit:
  	if (got_s_lock) {
  		row_mysql_unfreeze_data_dictionary(trx);
  	}
  
  	mem_heap_free(heap);
  
  	DEBUG_SYNC_C("foreign_constraint_check_for_update_done");
  	DBUG_RETURN(err);
  }
  
  /*********************************************************************//**
  Creates an update node for a query graph.
  @return own: update node */
  upd_node_t*
  upd_node_create(
  /*============*/
  	mem_heap_t*	heap)	/*!< in: mem heap where created */
  {
  	upd_node_t*	node;
  
  	node = static_cast<upd_node_t*>(
  		mem_heap_zalloc(heap, sizeof(upd_node_t)));
  
  	node->common.type = QUE_NODE_UPDATE;
  	node->state = UPD_NODE_UPDATE_CLUSTERED;
  	node->heap = mem_heap_create(128);
  	node->magic_n = UPD_NODE_MAGIC_N;
  
  	return(node);
  }
  #endif /* !UNIV_HOTBACKUP */
  
  /*********************************************************************//**
  Updates the trx id and roll ptr field in a clustered index record in database
  recovery. */
  void
  row_upd_rec_sys_fields_in_recovery(
  /*===============================*/
  	rec_t*		rec,	/*!< in/out: record */
  	page_zip_des_t*	page_zip,/*!< in/out: compressed page, or NULL */
  	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
  	ulint		pos,	/*!< in: TRX_ID position in rec */
  	trx_id_t	trx_id,	/*!< in: transaction id */
  	roll_ptr_t	roll_ptr)/*!< in: roll ptr of the undo log record */
  {
  	ut_ad(rec_offs_validate(rec, NULL, offsets));
  
  	if (page_zip) {
  		page_zip_write_trx_id_and_roll_ptr(
  			page_zip, rec, offsets, pos, trx_id, roll_ptr);
  	} else {
  		byte*	field;
  		ulint	len;
  
  		field = rec_get_nth_field(rec, offsets, pos, &len);
  		ut_ad(len == DATA_TRX_ID_LEN);
  #if DATA_TRX_ID + 1 != DATA_ROLL_PTR
  # error "DATA_TRX_ID + 1 != DATA_ROLL_PTR"
  #endif
  		trx_write_trx_id(field, trx_id);
  		trx_write_roll_ptr(field + DATA_TRX_ID_LEN, roll_ptr);
  	}
  }
  
  #ifndef UNIV_HOTBACKUP
  /*********************************************************************//**
  Sets the trx id or roll ptr field of a clustered index entry. */
  void
  row_upd_index_entry_sys_field(
  /*==========================*/
  	dtuple_t*	entry,	/*!< in/out: index entry, where the memory
  				buffers for sys fields are already allocated:
  				the function just copies the new values to
  				them */
  	dict_index_t*	index,	/*!< in: clustered index */
  	ulint		type,	/*!< in: DATA_TRX_ID or DATA_ROLL_PTR */
  	ib_uint64_t	val)	/*!< in: value to write */
  {
  	dfield_t*	dfield;
  	byte*		field;
  	ulint		pos;
  
  	ut_ad(dict_index_is_clust(index));
  
  	pos = dict_index_get_sys_col_pos(index, type);
  
  	dfield = dtuple_get_nth_field(entry, pos);
  	field = static_cast<byte*>(dfield_get_data(dfield));
  
  	if (type == DATA_TRX_ID) {
  		ut_ad(val > 0);
  		trx_write_trx_id(field, val);
  	} else {
  		ut_ad(type == DATA_ROLL_PTR);
  		trx_write_roll_ptr(field, val);
  	}
  }
  
  /***********************************************************//**
  Returns TRUE if row update changes size of some field in index or if some
  field to be updated is stored externally in rec or update.
  @return TRUE if the update changes the size of some field in index or
  the field is external in rec or update */
  ibool
  row_upd_changes_field_size_or_external(
  /*===================================*/
  	dict_index_t*	index,	/*!< in: index */
  	const ulint*	offsets,/*!< in: rec_get_offsets(rec, index) */
  	const upd_t*	update)	/*!< in: update vector */
  {
  	const upd_field_t*	upd_field;
  	const dfield_t*		new_val;
  	ulint			old_len;
  	ulint			new_len;
  	ulint			n_fields;
  	ulint			i;
  
  	ut_ad(rec_offs_validate(NULL, index, offsets));
  	n_fields = upd_get_n_fields(update);
  
  	for (i = 0; i < n_fields; i++) {
  		upd_field = upd_get_nth_field(update, i);
  
  		/* We should ignore virtual field if the index is not
  		a virtual index */
  		if (upd_fld_is_virtual_col(upd_field)
  		    && dict_index_has_virtual(index) != DICT_VIRTUAL) {
  			continue;
  		}
  
  		new_val = &(upd_field->new_val);
  		new_len = dfield_get_len(new_val);
  
  		if (dfield_is_null(new_val) && !rec_offs_comp(offsets)) {
  			/* A bug fixed on Dec 31st, 2004: we looked at the
  			SQL NULL size from the wrong field! We may backport
  			this fix also to 4.0. The merge to 5.0 will be made
  			manually immediately after we commit this to 4.1. */
  
  			new_len = dict_col_get_sql_null_size(
  				dict_index_get_nth_col(index,
  						       upd_field->field_no),
  				0);
  		}
  
  		old_len = rec_offs_nth_size(offsets, upd_field->field_no);
  
  		if (rec_offs_comp(offsets)
  		    && rec_offs_nth_sql_null(offsets,
  					     upd_field->field_no)) {
  			/* Note that in the compact table format, for a
  			variable length field, an SQL NULL will use zero
  			bytes in the offset array at the start of the physical
  			record, but a zero-length value (empty string) will
  			use one byte! Thus, we cannot use update-in-place
  			if we update an SQL NULL varchar to an empty string! */
  
  			old_len = UNIV_SQL_NULL;
  		}
  
  		if (dfield_is_ext(new_val) || old_len != new_len
  		    || rec_offs_nth_extern(offsets, upd_field->field_no)) {
  
  			return(TRUE);
  		}
  	}
  
  	return(FALSE);
  }
  
  /***********************************************************//**
  Returns true if row update contains disowned external fields.
  @return true if the update contains disowned external fields. */
  bool
  row_upd_changes_disowned_external(
  /*==============================*/
  	const upd_t*	update)	/*!< in: update vector */
  {
  	const upd_field_t*	upd_field;
  	const dfield_t*		new_val;
  	ulint			new_len;
  	ulint                   n_fields;
  	ulint			i;
  
  	n_fields = upd_get_n_fields(update);
  
  	for (i = 0; i < n_fields; i++) {
  		const byte*	field_ref;
  
  		upd_field = upd_get_nth_field(update, i);
  		new_val = &(upd_field->new_val);
  		new_len = dfield_get_len(new_val);
  
  		if (!dfield_is_ext(new_val)) {
  			continue;
  		}
  
  		ut_ad(new_len >= BTR_EXTERN_FIELD_REF_SIZE);
  
  		field_ref = static_cast<const byte*>(dfield_get_data(new_val))
  			    + new_len - BTR_EXTERN_FIELD_REF_SIZE;
  
  		if (field_ref[BTR_EXTERN_LEN] & BTR_EXTERN_OWNER_FLAG) {
  			return(true);
  		}
  	}
  
  	return(false);
  }
  #endif /* !UNIV_HOTBACKUP */
  
  /***********************************************************//**
  Replaces the new column values stored in the update vector to the
  record given. No field size changes are allowed. This function is
  usually invoked on a clustered index. The only use case for a
  secondary index is row_ins_sec_index_entry_by_modify() or its
  counterpart in ibuf_insert_to_index_page(). */
  void
  row_upd_rec_in_place(
  /*=================*/
  	rec_t*		rec,	/*!< in/out: record where replaced */
  	dict_index_t*	index,	/*!< in: the index the record belongs to */
  	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
  	const upd_t*	update,	/*!< in: update vector */
  	page_zip_des_t*	page_zip)/*!< in: compressed page with enough space
  				available, or NULL */
  {
  	const upd_field_t*	upd_field;
  	const dfield_t*		new_val;
  	ulint			n_fields;
  	ulint			i;
  
  	ut_ad(rec_offs_validate(rec, index, offsets));
  
  	if (rec_offs_comp(offsets)) {
  		rec_set_info_bits_new(rec, update->info_bits);
  	} else {
  		rec_set_info_bits_old(rec, update->info_bits);
  	}
  
  	n_fields = upd_get_n_fields(update);
  
  	for (i = 0; i < n_fields; i++) {
  		upd_field = upd_get_nth_field(update, i);
  
  		/* No need to update virtual columns for non-virtual index */
  		if (upd_fld_is_virtual_col(upd_field)
  		    && !dict_index_has_virtual(index)) {
  			continue;
  		}
  
  		new_val = &(upd_field->new_val);
  		ut_ad(!dfield_is_ext(new_val) ==
  		      !rec_offs_nth_extern(offsets, upd_field->field_no));
  
  		rec_set_nth_field(rec, offsets, upd_field->field_no,
  				  dfield_get_data(new_val),
  				  dfield_get_len(new_val));
  	}
  
  	if (page_zip) {
  		page_zip_write_rec(page_zip, rec, index, offsets, 0);
  	}
  }
  
  #ifndef UNIV_HOTBACKUP
  /*********************************************************************//**
  Writes into the redo log the values of trx id and roll ptr and enough info
  to determine their positions within a clustered index record.
  @return new pointer to mlog */
  byte*
  row_upd_write_sys_vals_to_log(
  /*==========================*/
  	dict_index_t*	index,	/*!< in: clustered index */
  	trx_id_t	trx_id,	/*!< in: transaction id */
  	roll_ptr_t	roll_ptr,/*!< in: roll ptr of the undo log record */
  	byte*		log_ptr,/*!< pointer to a buffer of size > 20 opened
  				in mlog */
  	mtr_t*		mtr MY_ATTRIBUTE((unused))) /*!< in: mtr */
  {
  	ut_ad(dict_index_is_clust(index));
  	ut_ad(mtr);
  
  	log_ptr += mach_write_compressed(log_ptr,
  					 dict_index_get_sys_col_pos(
  						 index, DATA_TRX_ID));
  
  	trx_write_roll_ptr(log_ptr, roll_ptr);
  	log_ptr += DATA_ROLL_PTR_LEN;
  
  	log_ptr += mach_u64_write_compressed(log_ptr, trx_id);
  
  	return(log_ptr);
  }
  #endif /* !UNIV_HOTBACKUP */
  
  /*********************************************************************//**
  Parses the log data of system field values.
  @return log data end or NULL */
  byte*
  row_upd_parse_sys_vals(
  /*===================*/
  	const byte*	ptr,	/*!< in: buffer */
  	const byte*	end_ptr,/*!< in: buffer end */
  	ulint*		pos,	/*!< out: TRX_ID position in record */
  	trx_id_t*	trx_id,	/*!< out: trx id */
  	roll_ptr_t*	roll_ptr)/*!< out: roll ptr */
  {
  	*pos = mach_parse_compressed(&ptr, end_ptr);
  
  	if (ptr == NULL) {
  
  		return(NULL);
  	}
  
  	if (end_ptr < ptr + DATA_ROLL_PTR_LEN) {
  
  		return(NULL);
  	}
  
  	*roll_ptr = trx_read_roll_ptr(ptr);
  	ptr += DATA_ROLL_PTR_LEN;
  
  	*trx_id = mach_u64_parse_compressed(&ptr, end_ptr);
  
  	return(const_cast<byte*>(ptr));
  }
  
  #ifndef UNIV_HOTBACKUP
  /***********************************************************//**
  Writes to the redo log the new values of the fields occurring in the index. */
  void
  row_upd_index_write_log(
  /*====================*/
  	const upd_t*	update,	/*!< in: update vector */
  	byte*		log_ptr,/*!< in: pointer to mlog buffer: must
  				contain at least MLOG_BUF_MARGIN bytes
  				of free space; the buffer is closed
  				within this function */
  	mtr_t*		mtr)	/*!< in: mtr into whose log to write */
  {
  	const upd_field_t*	upd_field;
  	const dfield_t*		new_val;
  	ulint			len;
  	ulint			n_fields;
  	byte*			buf_end;
  	ulint			i;
  
  	n_fields = upd_get_n_fields(update);
  
  	buf_end = log_ptr + MLOG_BUF_MARGIN;
  
  	mach_write_to_1(log_ptr, update->info_bits);
  	log_ptr++;
  	log_ptr += mach_write_compressed(log_ptr, n_fields);
  
  	for (i = 0; i < n_fields; i++) {
  
  #if MLOG_BUF_MARGIN <= 30
  # error "MLOG_BUF_MARGIN <= 30"
  #endif
  
  		if (log_ptr + 30 > buf_end) {
  			mlog_close(mtr, log_ptr);
  
  			log_ptr = mlog_open(mtr, MLOG_BUF_MARGIN);
  			buf_end = log_ptr + MLOG_BUF_MARGIN;
  		}
  
  		upd_field = upd_get_nth_field(update, i);
  
  		new_val = &(upd_field->new_val);
  
  		len = dfield_get_len(new_val);
  
  		/* If this is a virtual column, mark it using special
  		field_no */
  		ulint	field_no = upd_fld_is_virtual_col(upd_field)
  				   ? REC_MAX_N_FIELDS + upd_field->field_no
  				   : upd_field->field_no;
  
  		log_ptr += mach_write_compressed(log_ptr, field_no);
  		log_ptr += mach_write_compressed(log_ptr, len);
  
  		if (len != UNIV_SQL_NULL) {
  			if (log_ptr + len < buf_end) {
  				memcpy(log_ptr, dfield_get_data(new_val), len);
  
  				log_ptr += len;
  			} else {
  				mlog_close(mtr, log_ptr);
  
  				mlog_catenate_string(
  					mtr,
  					static_cast<byte*>(
  						dfield_get_data(new_val)),
  					len);
  
  				log_ptr = mlog_open(mtr, MLOG_BUF_MARGIN);
  				buf_end = log_ptr + MLOG_BUF_MARGIN;
  			}
  		}
  	}
  
  	mlog_close(mtr, log_ptr);
  }
  #endif /* !UNIV_HOTBACKUP */
  
  /*********************************************************************//**
  Parses the log data written by row_upd_index_write_log.
  @return log data end or NULL */
  byte*
  row_upd_index_parse(
  /*================*/
  	const byte*	ptr,	/*!< in: buffer */
  	const byte*	end_ptr,/*!< in: buffer end */
  	mem_heap_t*	heap,	/*!< in: memory heap where update vector is
  				built */
  	upd_t**		update_out)/*!< out: update vector */
  {
  	upd_t*		update;
  	upd_field_t*	upd_field;
  	dfield_t*	new_val;
  	ulint		len;
  	ulint		n_fields;
  	ulint		info_bits;
  	ulint		i;
  
  	if (end_ptr < ptr + 1) {
  
  		return(NULL);
  	}
  
  	info_bits = mach_read_from_1(ptr);
  	ptr++;
  	n_fields = mach_parse_compressed(&ptr, end_ptr);
  
  	if (ptr == NULL) {
  
  		return(NULL);
  	}
  
  	update = upd_create(n_fields, heap);
  	update->info_bits = info_bits;
  
  	for (i = 0; i < n_fields; i++) {
  		ulint	field_no;
  		upd_field = upd_get_nth_field(update, i);
  		new_val = &(upd_field->new_val);
  
  		field_no = mach_parse_compressed(&ptr, end_ptr);
  
  		if (ptr == NULL) {
  
  			return(NULL);
  		}
  
  		/* Check if this is a virtual column, mark the prtype
  		if that is the case */
  		if (field_no >= REC_MAX_N_FIELDS) {
  			new_val->type.prtype |= DATA_VIRTUAL;
  			field_no -= REC_MAX_N_FIELDS;
  		}
  
  		upd_field->field_no = field_no;
  
  		len = mach_parse_compressed(&ptr, end_ptr);
  
  		if (ptr == NULL) {
  
  			return(NULL);
  		}
  
  		if (len != UNIV_SQL_NULL) {
  
  			if (end_ptr < ptr + len) {
  
  				return(NULL);
  			}
  
  			dfield_set_data(new_val,
  					mem_heap_dup(heap, ptr, len), len);
  			ptr += len;
  		} else {
  			dfield_set_null(new_val);
  		}
  	}
  
  	*update_out = update;
  
  	return(const_cast<byte*>(ptr));
  }
  
  #ifndef UNIV_HOTBACKUP
  /***************************************************************//**
  Builds an update vector from those fields which in a secondary index entry
  differ from a record that has the equal ordering fields. NOTE: we compare
  the fields as binary strings!
  @return own: update vector of differing fields */
  upd_t*
  row_upd_build_sec_rec_difference_binary(
  /*====================================*/
  	const rec_t*	rec,	/*!< in: secondary index record */
  	dict_index_t*	index,	/*!< in: index */
  	const ulint*	offsets,/*!< in: rec_get_offsets(rec, index) */
  	const dtuple_t*	entry,	/*!< in: entry to insert */
  	mem_heap_t*	heap)	/*!< in: memory heap from which allocated */
  {
  	upd_field_t*	upd_field;
  	const dfield_t*	dfield;
  	const byte*	data;
  	ulint		len;
  	upd_t*		update;
  	ulint		n_diff;
  	ulint		i;
  
  	/* This function is used only for a secondary index */
  	ut_a(!dict_index_is_clust(index));
  	ut_ad(rec_offs_validate(rec, index, offsets));
  	ut_ad(rec_offs_n_fields(offsets) == dtuple_get_n_fields(entry));
  	ut_ad(!rec_offs_any_extern(offsets));
  
  	update = upd_create(dtuple_get_n_fields(entry), heap);
  
  	n_diff = 0;
  
  	for (i = 0; i < dtuple_get_n_fields(entry); i++) {
  
  		data = rec_get_nth_field(rec, offsets, i, &len);
  
  		dfield = dtuple_get_nth_field(entry, i);
  
  		/* NOTE that it may be that len != dfield_get_len(dfield) if we
  		are updating in a character set and collation where strings of
  		different length can be equal in an alphabetical comparison,
  		and also in the case where we have a column prefix index
  		and the last characters in the index field are spaces; the
  		latter case probably caused the assertion failures reported at
  		row0upd.cc line 713 in versions 4.0.14 - 4.0.16. */
  
  		/* NOTE: we compare the fields as binary strings!
  		(No collation) */
  
  		if (!dfield_data_is_binary_equal(dfield, len, data)) {
  
  			upd_field = upd_get_nth_field(update, n_diff);
  
  			dfield_copy(&(upd_field->new_val), dfield);
  
  			upd_field_set_field_no(upd_field, i, index, NULL);
  
  			n_diff++;
  		}
  	}
  
  	update->n_fields = n_diff;
  
  	return(update);
  }
  
  /** Builds an update vector from those fields, excluding the roll ptr and
  trx id fields, which in an index entry differ from a record that has
  the equal ordering fields. NOTE: we compare the fields as binary strings!
  @param[in]	index		clustered index
  @param[in]	entry		clustered index entry to insert
  @param[in]	rec		clustered index record
  @param[in]	offsets		rec_get_offsets(rec,index), or NULL
  @param[in]	no_sys		skip the system columns
  				DB_TRX_ID and DB_ROLL_PTR
  @param[in]	trx		transaction (for diagnostics),
  				or NULL
  @param[in]	heap		memory heap from which allocated
  @param[in]	mysql_table	NULL, or mysql table object when
  				user thread invokes dml
  @return own: update vector of differing fields, excluding roll ptr and
  trx id */
  upd_t*
  row_upd_build_difference_binary(
  	dict_index_t*	index,
  	const dtuple_t*	entry,
  	const rec_t*	rec,
  	const ulint*	offsets,
  	bool		no_sys,
  	trx_t*		trx,
  	mem_heap_t*	heap,
  	TABLE*		mysql_table)
  {
  	upd_field_t*	upd_field;
  	dfield_t*	dfield;
  	const byte*	data;
  	ulint		len;
  	upd_t*		update;
  	ulint		n_diff;
  	ulint		trx_id_pos;
  	ulint		i;
  	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
  	ulint		n_fld = dtuple_get_n_fields(entry);
  	ulint		n_v_fld = dtuple_get_n_v_fields(entry);
  	rec_offs_init(offsets_);
  
  	/* This function is used only for a clustered index */
  	ut_a(dict_index_is_clust(index));
  
  	update = upd_create(n_fld + n_v_fld, heap);
  
  	n_diff = 0;
  
  	trx_id_pos = dict_index_get_sys_col_pos(index, DATA_TRX_ID);
  	ut_ad(dict_table_is_intrinsic(index->table)
  	      || (dict_index_get_sys_col_pos(index, DATA_ROLL_PTR)
  			== trx_id_pos + 1));
  
  	if (!offsets) {
  		offsets = rec_get_offsets(rec, index, offsets_,
  					  ULINT_UNDEFINED, &heap);
  	} else {
  		ut_ad(rec_offs_validate(rec, index, offsets));
  	}
  
  	for (i = 0; i < n_fld; i++) {
  
  		data = rec_get_nth_field(rec, offsets, i, &len);
  
  		dfield = dtuple_get_nth_field(entry, i);
  
  		/* NOTE: we compare the fields as binary strings!
  		(No collation) */
  		if (no_sys) {
  			/* TRX_ID */
  			if (i == trx_id_pos) {
  				continue;
  			}
  
  			/* DB_ROLL_PTR */
  			if (i == trx_id_pos + 1
  			    && !dict_table_is_intrinsic(index->table)) {
  				continue;
  			}
  		}
  
  		if (!dfield_is_ext(dfield)
  		    != !rec_offs_nth_extern(offsets, i)
  		    || !dfield_data_is_binary_equal(dfield, len, data)) {
  
  			upd_field = upd_get_nth_field(update, n_diff);
  
  			dfield_copy(&(upd_field->new_val), dfield);
  
  			upd_field_set_field_no(upd_field, i, index, trx);
  
  			n_diff++;
  		}
  	}
  
  	/* Check the virtual columns updates. Even if there is no non-virtual
  	column (base columns) change, we will still need to build the
  	indexed virtual column value so that undo log would log them (
  	for purge/mvcc purpose) */
  	if (n_v_fld > 0) {
  		row_ext_t*	ext;
  		mem_heap_t*	v_heap = NULL;
  		THD*		thd;
  
  		if (trx == NULL) {
  			thd = current_thd;
  		} else {
  			thd = trx->mysql_thd;
  		}
  
  		ut_ad(!update->old_vrow);
  
  		for (i = 0; i < n_v_fld; i++) {
  			const dict_v_col_t*     col
                                  = dict_table_get_nth_v_col(index->table, i);
  
  			if (!col->m_col.ord_part) {
  				continue;
  			}
  
  			if (update->old_vrow == NULL) {
  				update->old_vrow = row_build(
  					ROW_COPY_POINTERS, index, rec, offsets,
  					index->table, NULL, NULL, &ext, heap);
  			}
  
  			dfield = dtuple_get_nth_v_field(entry, i);
  
  			dfield_t*	vfield = innobase_get_computed_value(
  				update->old_vrow, col, index,
  				&v_heap, heap, NULL, thd, mysql_table,
  				NULL, NULL, NULL);
  
  			if (!dfield_data_is_binary_equal(
  				dfield, vfield->len,
  				static_cast<byte*>(vfield->data))) {
  				upd_field = upd_get_nth_field(update, n_diff);
  
  				upd_field->old_v_val = static_cast<dfield_t*>(
  					mem_heap_alloc(
  						heap,
  						sizeof *upd_field->old_v_val));
  
  				dfield_copy(upd_field->old_v_val, vfield);
  
  				dfield_copy(&(upd_field->new_val), dfield);
  
  				upd_field_set_v_field_no(
  					upd_field, i, index);
  
  				n_diff++;
  
  			}
  		}
  
  		if (v_heap) {
  			mem_heap_free(v_heap);
  		}
  	}
  
  	update->n_fields = n_diff;
  	ut_ad(update->validate());
  
  	return(update);
  }
  
  /** Fetch a prefix of an externally stored column.
  This is similar to row_ext_lookup(), but the row_ext_t holds the old values
  of the column and must not be poisoned with the new values.
  @param[in]	data		'internally' stored part of the field
  containing also the reference to the external part
  @param[in]	local_len	length of data, in bytes
  @param[in]	page_size	BLOB page size
  @param[in,out]	len		input - length of prefix to
  fetch; output: fetched length of the prefix
  @param[in,out]	heap		heap where to allocate
  @return BLOB prefix */
  static
  byte*
  row_upd_ext_fetch(
  	const byte*		data,
  	ulint			local_len,
  	const page_size_t&	page_size,
  	ulint*			len,
  	mem_heap_t*		heap)
  {
  	byte*	buf = static_cast<byte*>(mem_heap_alloc(heap, *len));
  
  	*len = btr_copy_externally_stored_field_prefix(
  		buf, *len, page_size, data, local_len);
  
  	/* We should never update records containing a half-deleted BLOB. */
  	ut_a(*len);
  
  	return(buf);
  }
  
  /** Replaces the new column value stored in the update vector in
  the given index entry field.
  @param[in,out]	dfield		data field of the index entry
  @param[in]	field		index field
  @param[in]	col		field->col
  @param[in]	uf		update field
  @param[in,out]	heap		memory heap for allocating and copying
  the new value
  @param[in]	page_size	page size */
  static
  void
  row_upd_index_replace_new_col_val(
  	dfield_t*		dfield,
  	const dict_field_t*	field,
  	const dict_col_t*	col,
  	const upd_field_t*	uf,
  	mem_heap_t*		heap,
  	const page_size_t&	page_size)
  {
  	ulint		len;
  	const byte*	data;
  
  	dfield_copy_data(dfield, &uf->new_val);
  
  	if (dfield_is_null(dfield)) {
  		return;
  	}
  
  	len = dfield_get_len(dfield);
  	data = static_cast<const byte*>(dfield_get_data(dfield));
  
  	if (field->prefix_len > 0) {
  		ibool		fetch_ext = dfield_is_ext(dfield)
  			&& len < (ulint) field->prefix_len
  			+ BTR_EXTERN_FIELD_REF_SIZE;
  
  		if (fetch_ext) {
  			ulint	l = len;
  
  			len = field->prefix_len;
  
  			data = row_upd_ext_fetch(data, l, page_size,
  						 &len, heap);
  		}
  
  		len = dtype_get_at_most_n_mbchars(col->prtype,
  						  col->mbminmaxlen,
  						  field->prefix_len, len,
  						  (const char*) data);
  
  		dfield_set_data(dfield, data, len);
  
  		if (!fetch_ext) {
  			dfield_dup(dfield, heap);
  		}
  
  		return;
  	}
  
  	switch (uf->orig_len) {
  		byte*	buf;
  	case BTR_EXTERN_FIELD_REF_SIZE:
  		/* Restore the original locally stored
  		part of the column.  In the undo log,
  		InnoDB writes a longer prefix of externally
  		stored columns, so that column prefixes
  		in secondary indexes can be reconstructed. */
  		dfield_set_data(dfield,
  				data + len - BTR_EXTERN_FIELD_REF_SIZE,
  				BTR_EXTERN_FIELD_REF_SIZE);
  		dfield_set_ext(dfield);
  		/* fall through */
  	case 0:
  		dfield_dup(dfield, heap);
  		break;
  	default:
  		/* Reconstruct the original locally
  		stored part of the column.  The data
  		will have to be copied. */
  		ut_a(uf->orig_len > BTR_EXTERN_FIELD_REF_SIZE);
  		buf = static_cast<byte*>(mem_heap_alloc(heap, uf->orig_len));
  
  		/* Copy the locally stored prefix. */
  		memcpy(buf, data,
  		       uf->orig_len - BTR_EXTERN_FIELD_REF_SIZE);
  
  		/* Copy the BLOB pointer. */
  		memcpy(buf + uf->orig_len - BTR_EXTERN_FIELD_REF_SIZE,
  		       data + len - BTR_EXTERN_FIELD_REF_SIZE,
  		       BTR_EXTERN_FIELD_REF_SIZE);
  
  		dfield_set_data(dfield, buf, uf->orig_len);
  		dfield_set_ext(dfield);
  		break;
  	}
  }
  
  /***********************************************************//**
  Replaces the new column values stored in the update vector to the index entry
  given. */
  void
  row_upd_index_replace_new_col_vals_index_pos(
  /*=========================================*/
  	dtuple_t*	entry,	/*!< in/out: index entry where replaced;
  				the clustered index record must be
  				covered by a lock or a page latch to
  				prevent deletion (rollback or purge) */
  	dict_index_t*	index,	/*!< in: index; NOTE that this may also be a
  				non-clustered index */
  	const upd_t*	update,	/*!< in: an update vector built for the index so
  				that the field number in an upd_field is the
  				index position */
  	ibool		order_only,
  				/*!< in: if TRUE, limit the replacement to
  				ordering fields of index; note that this
  				does not work for non-clustered indexes. */
  	mem_heap_t*	heap)	/*!< in: memory heap for allocating and
  				copying the new values */
  {
  	ulint		i;
  	ulint		n_fields;
  	const page_size_t&	page_size = dict_table_page_size(index->table);
  
  	ut_ad(index);
  
  	dtuple_set_info_bits(entry, update->info_bits);
  
  	if (order_only) {
  		n_fields = dict_index_get_n_unique(index);
  	} else {
  		n_fields = dict_index_get_n_fields(index);
  	}
  
  	for (i = 0; i < n_fields; i++) {
  		const dict_field_t*	field;
  		const dict_col_t*	col;
  		const upd_field_t*	uf;
  
  		field = dict_index_get_nth_field(index, i);
  		col = dict_field_get_col(field);
  		if (dict_col_is_virtual(col)) {
  			const dict_v_col_t*	vcol = reinterpret_cast<
  							const dict_v_col_t*>(
  								col);
  
  			uf = upd_get_field_by_field_no(
  				update, vcol->v_pos, true);
  		} else {
  			uf = upd_get_field_by_field_no(
  				update, i, false);
  		}
  
  		if (uf) {
  			row_upd_index_replace_new_col_val(
  				dtuple_get_nth_field(entry, i),
  				field, col, uf, heap, page_size);
  		}
  	}
  }
  
  /***********************************************************//**
  Replaces the new column values stored in the update vector to the index entry
  given. */
  void
  row_upd_index_replace_new_col_vals(
  /*===============================*/
  	dtuple_t*	entry,	/*!< in/out: index entry where replaced;
  				the clustered index record must be
  				covered by a lock or a page latch to
  				prevent deletion (rollback or purge) */
  	dict_index_t*	index,	/*!< in: index; NOTE that this may also be a
  				non-clustered index */
  	const upd_t*	update,	/*!< in: an update vector built for the
  				CLUSTERED index so that the field number in
  				an upd_field is the clustered index position */
  	mem_heap_t*	heap)	/*!< in: memory heap for allocating and
  				copying the new values */
  {
  	ulint			i;
  	const dict_index_t*	clust_index
  		= dict_table_get_first_index(index->table);
  	const page_size_t&	page_size = dict_table_page_size(index->table);
  
  	dtuple_set_info_bits(entry, update->info_bits);
  
  	for (i = 0; i < dict_index_get_n_fields(index); i++) {
  		const dict_field_t*	field;
  		const dict_col_t*	col;
  		const upd_field_t*	uf;
  
  		field = dict_index_get_nth_field(index, i);
  		col = dict_field_get_col(field);
  		if (dict_col_is_virtual(col)) {
  			const dict_v_col_t*	vcol = reinterpret_cast<
  							const dict_v_col_t*>(
  								col);
  
  			uf = upd_get_field_by_field_no(
  				update, vcol->v_pos, true);
  		} else {
  			uf = upd_get_field_by_field_no(
  				update,
  				dict_col_get_clust_pos(col, clust_index),
  				false);
  		}
  
  		if (uf) {
  			row_upd_index_replace_new_col_val(
  				dtuple_get_nth_field(entry, i),
  				field, col, uf, heap, page_size);
  		}
  	}
  }
  
  /** Replaces the virtual column values stored in the update vector.
  @param[in,out]	row	row whose column to be set
  @param[in]	field	data to set
  @param[in]	len	data length
  @param[in]	vcol	virtual column info */
  static
  void
  row_upd_set_vcol_data(
  	dtuple_t*		row,
  	const byte*             field,
  	ulint                   len,
  	dict_v_col_t*		vcol)
  {
  	dfield_t*	dfield = dtuple_get_nth_v_field(row, vcol->v_pos);
  
  	if (dfield_get_type(dfield)->mtype == DATA_MISSING) {
  		dict_col_copy_type(&vcol->m_col, dfield_get_type(dfield));
  
  		dfield_set_data(dfield, field, len);
  	}
  }
  
  /** Replaces the virtual column values stored in a dtuple with that of
  a update vector.
  @param[in,out]	row	row whose column to be updated
  @param[in]	table	table
  @param[in]	update	an update vector built for the clustered index
  @param[in]	upd_new	update to new or old value
  @param[in,out]	undo_row undo row (if needs to be updated)
  @param[in]	ptr	remaining part in update undo log */
  void
  row_upd_replace_vcol(
  	dtuple_t*		row,
  	const dict_table_t*	table,
  	const upd_t*		update,
  	bool			upd_new,
  	dtuple_t*		undo_row,
  	const byte*		ptr)
  {
  	ulint			col_no;
  	ulint			i;
  	ulint			n_cols;
  
  	n_cols = dtuple_get_n_v_fields(row);
  	for (col_no = 0; col_no < n_cols; col_no++) {
  		dfield_t*		dfield;
  
  		const dict_v_col_t*	col
  			= dict_table_get_nth_v_col(table, col_no);
  
  		/* If there is no index on the column, do not bother for
  		value update */
  		if (!col->m_col.ord_part) {
  			dict_index_t*	clust_index
  				= dict_table_get_first_index(table);
  
  			/* Skip the column if there is no online alter
  			table in progress or it is not being indexed
  			in new table */
  			if (!dict_index_is_online_ddl(clust_index)
  			    || !row_log_col_is_indexed(clust_index, col_no)) {
  				continue;
  			}
  		}
  
  		dfield = dtuple_get_nth_v_field(row, col_no);
  
  		for (i = 0; i < upd_get_n_fields(update); i++) {
  			const upd_field_t*	upd_field
  				= upd_get_nth_field(update, i);
  			if (!upd_fld_is_virtual_col(upd_field)
  			    || upd_field->field_no != col->v_pos) {
  				continue;
  			}
  
  			if (upd_new) {
  				dfield_copy_data(dfield, &upd_field->new_val);
  			} else {
  				dfield_copy_data(dfield, upd_field->old_v_val);
  			}
  
  			dfield_get_type(dfield)->mtype =
  				upd_field->new_val.type.mtype;
  			dfield_get_type(dfield)->prtype =
  				upd_field->new_val.type.prtype;
  			dfield_get_type(dfield)->mbminmaxlen =
  				upd_field->new_val.type.mbminmaxlen;
  			break;
  		}
  	}
  
  	bool	first_v_col = true;
  	bool	is_undo_log = true;
  
  	/* We will read those unchanged (but indexed) virtual columns in */
  	if (ptr != NULL) {
  		const byte*	end_ptr;
  
  		end_ptr = ptr + mach_read_from_2(ptr);
  		ptr += 2;
  
  		while (ptr != end_ptr) {
  			const byte*             field;
  			ulint                   field_no;
  			ulint                   len;
  			ulint                   orig_len;
  			bool			is_v;
  
  			field_no = mach_read_next_compressed(&ptr);
  
  			is_v = (field_no >= REC_MAX_N_FIELDS);
  
  			if (is_v) {
  				ptr = trx_undo_read_v_idx(
  					table, ptr, first_v_col, &is_undo_log,
  					&field_no);
  				first_v_col = false;
  			}
  
  			ptr = trx_undo_rec_get_col_val(
  				ptr, &field, &len, &orig_len);
  
  			if (field_no == ULINT_UNDEFINED) {
  				ut_ad(is_v);
  				continue;
  			}
  
  			if (is_v) {
  				dict_v_col_t* vcol = dict_table_get_nth_v_col(
  							table, field_no);
  
  				row_upd_set_vcol_data(row, field, len, vcol);
  
  				if (undo_row) {
  					row_upd_set_vcol_data(
  						undo_row, field, len, vcol);
  				}
  			}
  			ut_ad(ptr<= end_ptr);
  		}
  	}
  }
  
  /***********************************************************//**
  Replaces the new column values stored in the update vector. */
  void
  row_upd_replace(
  /*============*/
  	dtuple_t*		row,	/*!< in/out: row where replaced,
  					indexed by col_no;
  					the clustered index record must be
  					covered by a lock or a page latch to
  					prevent deletion (rollback or purge) */
  	row_ext_t**		ext,	/*!< out, own: NULL, or externally
  					stored column prefixes */
  	const dict_index_t*	index,	/*!< in: clustered index */
  	const upd_t*		update,	/*!< in: an update vector built for the
  					clustered index */
  	mem_heap_t*		heap)	/*!< in: memory heap */
  {
  	ulint			col_no;
  	ulint			i;
  	ulint			n_cols;
  	ulint			n_ext_cols;
  	ulint*			ext_cols;
  	const dict_table_t*	table;
  
  	ut_ad(row);
  	ut_ad(ext);
  	ut_ad(index);
  	ut_ad(dict_index_is_clust(index));
  	ut_ad(update);
  	ut_ad(heap);
  	ut_ad(update->validate());
  
  	n_cols = dtuple_get_n_fields(row);
  	table = index->table;
  	ut_ad(n_cols == dict_table_get_n_cols(table));
  
  	ext_cols = static_cast<ulint*>(
  		mem_heap_alloc(heap, n_cols * sizeof *ext_cols));
  
  	n_ext_cols = 0;
  
  	dtuple_set_info_bits(row, update->info_bits);
  
  	for (col_no = 0; col_no < n_cols; col_no++) {
  
  		const dict_col_t*	col
  			= dict_table_get_nth_col(table, col_no);
  		const ulint		clust_pos
  			= dict_col_get_clust_pos(col, index);
  		dfield_t*		dfield;
  
  		if (UNIV_UNLIKELY(clust_pos == ULINT_UNDEFINED)) {
  
  			continue;
  		}
  
  		dfield = dtuple_get_nth_field(row, col_no);
  
  		for (i = 0; i < upd_get_n_fields(update); i++) {
  
  			const upd_field_t*	upd_field
  				= upd_get_nth_field(update, i);
  
  			if (upd_field->field_no != clust_pos
  			    || upd_fld_is_virtual_col(upd_field)) {
  
  				continue;
  			}
  
  			dfield_copy_data(dfield, &upd_field->new_val);
  			break;
  		}
  
  		if (dfield_is_ext(dfield) && col->ord_part) {
  			ext_cols[n_ext_cols++] = col_no;
  		}
  	}
  
  	if (n_ext_cols) {
  		*ext = row_ext_create(n_ext_cols, ext_cols, table->flags, row,
  				      heap);
  	} else {
  		*ext = NULL;
  	}
  
  	row_upd_replace_vcol(row, table, update, true, NULL, NULL);
  }
  
  /***********************************************************//**
  Checks if an update vector changes an ordering field of an index record.
  
  This function is fast if the update vector is short or the number of ordering
  fields in the index is small. Otherwise, this can be quadratic.
  NOTE: we compare the fields as binary strings!
  @return TRUE if update vector changes an ordering field in the index record */
  ibool
  row_upd_changes_ord_field_binary_func(
  /*==================================*/
  	dict_index_t*	index,	/*!< in: index of the record */
  	const upd_t*	update,	/*!< in: update vector for the row; NOTE: the
  				field numbers in this MUST be clustered index
  				positions! */
  #ifdef UNIV_DEBUG
  	const que_thr_t*thr,	/*!< in: query thread */
  #endif /* UNIV_DEBUG */
  	const dtuple_t*	row,	/*!< in: old value of row, or NULL if the
  				row and the data values in update are not
  				known when this function is called, e.g., at
  				compile time */
  	const row_ext_t*ext,	/*!< NULL, or prefixes of the externally
  				stored columns in the old row */
  	ulint		flag)	/*!< in: ROW_BUILD_NORMAL,
  				ROW_BUILD_FOR_PURGE or ROW_BUILD_FOR_UNDO */
  {
  	ulint			n_unique;
  	ulint			i;
  	const dict_index_t*	clust_index;
  
  	ut_ad(index);
  	ut_ad(update);
  	ut_ad(thr);
  	ut_ad(thr->graph);
  	ut_ad(thr->graph->trx);
  
  	n_unique = dict_index_get_n_unique(index);
  
  	clust_index = dict_table_get_first_index(index->table);
  
  	for (i = 0; i < n_unique; i++) {
  
  		const dict_field_t*	ind_field;
  		const dict_col_t*	col;
  		ulint			col_no;
  		const upd_field_t*	upd_field;
  		const dfield_t*		dfield;
  		dfield_t		dfield_ext;
  		ulint			dfield_len;
  		const byte*		buf;
  		bool			is_virtual;
  		const dict_v_col_t*	vcol = NULL;
  
  		ind_field = dict_index_get_nth_field(index, i);
  		col = dict_field_get_col(ind_field);
  		col_no = dict_col_get_no(col);
  		is_virtual = dict_col_is_virtual(col);
  
  		if (is_virtual) {
  			vcol = reinterpret_cast<const dict_v_col_t*>(col);
  
  			upd_field = upd_get_field_by_field_no(
  				update, vcol->v_pos, true);
  		} else {
  			upd_field = upd_get_field_by_field_no(
  				update,
  				dict_col_get_clust_pos(col, clust_index),
  				false);
  		}
  
  		if (upd_field == NULL) {
  			continue;
  		}
  
  		if (row == NULL) {
  			ut_ad(ext == NULL);
  			return(TRUE);
  		}
  
  		if (is_virtual) {
  			dfield = dtuple_get_nth_v_field(
  				row,  vcol->v_pos);
  		} else {
  			dfield = dtuple_get_nth_field(row, col_no);
  		}
  
  		/* For spatial index update, since the different geometry
  		data could generate same MBR, so, if the new index entry is
  		same as old entry, which means the MBR is not changed, we
  		don't need to do anything. */
  		if (dict_index_is_spatial(index) && i == 0) {
  			double		mbr1[SPDIMS * 2];
  			double		mbr2[SPDIMS * 2];
  			rtr_mbr_t*	old_mbr;
  			rtr_mbr_t*	new_mbr;
  			uchar*		dptr = NULL;
  			ulint		flen = 0;
  			ulint		dlen = 0;
  			mem_heap_t*	temp_heap = NULL;
  			const dfield_t*	new_field = &upd_field->new_val;
  
  			const page_size_t	page_size
  				= (ext != NULL)
  				? ext->page_size
  				: dict_table_page_size(
  					index->table);
  
  			ut_ad(dfield->data != NULL
  			      && dfield->len > GEO_DATA_HEADER_SIZE);
  			ut_ad(dict_col_get_spatial_status(col) != SPATIAL_NONE);
  
  			/* Get the old mbr. */
  			if (dfield_is_ext(dfield)) {
  				/* For off-page stored data, we
  				need to read the whole field data. */
  				flen = dfield_get_len(dfield);
  				dptr = static_cast<byte*>(
  					dfield_get_data(dfield));
  				temp_heap = mem_heap_create(1000);
  
  				dptr = btr_copy_externally_stored_field(
  					&dlen, dptr,
  					page_size,
  					flen,
  					temp_heap);
  			} else {
  				dptr = static_cast<uchar*>(dfield->data);
  				dlen = dfield->len;
  			}
  
  			rtree_mbr_from_wkb(dptr + GEO_DATA_HEADER_SIZE,
  					   static_cast<uint>(dlen
  					   - GEO_DATA_HEADER_SIZE),
  					   SPDIMS, mbr1);
  			old_mbr = reinterpret_cast<rtr_mbr_t*>(mbr1);
  
  			/* Get the new mbr. */
  			if (dfield_is_ext(new_field)) {
  				if (flag == ROW_BUILD_FOR_UNDO
  				    && dict_table_get_format(index->table)
  					>= UNIV_FORMAT_B) {
  					/* For undo, and the table is Barrcuda,
  					we need to skip the prefix data. */
  					flen = BTR_EXTERN_FIELD_REF_SIZE;
  					ut_ad(dfield_get_len(new_field) >=
  					      BTR_EXTERN_FIELD_REF_SIZE);
  					dptr = static_cast<byte*>(
  						dfield_get_data(new_field))
  						+ dfield_get_len(new_field)
  						- BTR_EXTERN_FIELD_REF_SIZE;
  				} else {
  					flen = dfield_get_len(new_field);
  					dptr = static_cast<byte*>(
  						dfield_get_data(new_field));
  				}
  
  				if (temp_heap == NULL) {
  					temp_heap = mem_heap_create(1000);
  				}
  
  				dptr = btr_copy_externally_stored_field(
  					&dlen, dptr,
  					page_size,
  					flen,
  					temp_heap);
  			} else {
  				dptr = static_cast<uchar*>(upd_field->new_val.data);
  				dlen = upd_field->new_val.len;
  			}
  			rtree_mbr_from_wkb(dptr + GEO_DATA_HEADER_SIZE,
  					   static_cast<uint>(dlen
  					   - GEO_DATA_HEADER_SIZE),
  					   SPDIMS, mbr2);
  			new_mbr = reinterpret_cast<rtr_mbr_t*>(mbr2);
  
  			if (temp_heap) {
  				mem_heap_free(temp_heap);
  			}
  
  			if (!MBR_EQUAL_CMP(old_mbr, new_mbr)) {
  				return(TRUE);
  			} else {
  				continue;
  			}
  		}
  
  		/* This treatment of column prefix indexes is loosely
  		based on row_build_index_entry(). */
  
  		if (UNIV_LIKELY(ind_field->prefix_len == 0)
  		    || dfield_is_null(dfield)) {
  			/* do nothing special */
  		} else if (ext) {
  			/* Silence a compiler warning without
  			silencing a Valgrind error. */
  			dfield_len = 0;
  			UNIV_MEM_INVALID(&dfield_len, sizeof dfield_len);
  			/* See if the column is stored externally. */
  			buf = row_ext_lookup(ext, col_no, &dfield_len);
  
  			ut_ad(col->ord_part);
  
  			if (UNIV_LIKELY_NULL(buf)) {
  				if (UNIV_UNLIKELY(buf == field_ref_zero)) {
  					/* The externally stored field
  					was not written yet. This
  					record should only be seen by
  					recv_recovery_rollback_active(),
  					when the server had crashed before
  					storing the field. */
  					ut_ad(thr->graph->trx->is_recovered);
  					ut_ad(trx_is_recv(thr->graph->trx));
  					return(TRUE);
  				}
  
  				goto copy_dfield;
  			}
  		} else if (dfield_is_ext(dfield)) {
  			dfield_len = dfield_get_len(dfield);
  			ut_a(dfield_len > BTR_EXTERN_FIELD_REF_SIZE);
  			dfield_len -= BTR_EXTERN_FIELD_REF_SIZE;
  			ut_a(dict_index_is_clust(index)
  			     || ind_field->prefix_len <= dfield_len);
  
  			buf = static_cast<byte*>(dfield_get_data(dfield));
  copy_dfield:
  			ut_a(dfield_len > 0);
  			dfield_copy(&dfield_ext, dfield);
  			dfield_set_data(&dfield_ext, buf, dfield_len);
  			dfield = &dfield_ext;
  		}
  
  		if (!dfield_datas_are_binary_equal(
  			    dfield, &upd_field->new_val,
  			    ind_field->prefix_len)) {
  
  			return(TRUE);
  		}
  	}
  
  	return(FALSE);
  }
  
  /***********************************************************//**
  Checks if an update vector changes an ordering field of an index record.
  NOTE: we compare the fields as binary strings!
  @return TRUE if update vector may change an ordering field in an index
  record */
  ibool
  row_upd_changes_some_index_ord_field_binary(
  /*========================================*/
  	const dict_table_t*	table,	/*!< in: table */
  	const upd_t*		update)	/*!< in: update vector for the row */
  {
  	upd_field_t*	upd_field;
  	dict_index_t*	index;
  	ulint		i;
  
  	index = dict_table_get_first_index(table);
  
  	for (i = 0; i < upd_get_n_fields(update); i++) {
  
  		upd_field = upd_get_nth_field(update, i);
  
  		if (upd_fld_is_virtual_col(upd_field)) {
  			if (dict_table_get_nth_v_col(index->table,
  						     upd_field->field_no)
  			    ->m_col.ord_part) {
  				return(TRUE);
  			}
  		} else {
  			if (dict_field_get_col(dict_index_get_nth_field(
  				index, upd_field->field_no))->ord_part) {
  				return(TRUE);
  			}
  		}
  	}
  
  	return(FALSE);
  }
  
  /***********************************************************//**
  Checks if an FTS Doc ID column is affected by an UPDATE.
  @return whether the Doc ID column is changed */
  bool
  row_upd_changes_doc_id(
  /*===================*/
  	dict_table_t*	table,		/*!< in: table */
  	upd_field_t*	upd_field)	/*!< in: field to check */
  {
  	ulint		col_no;
  	dict_index_t*	clust_index;
  	fts_t*		fts = table->fts;
  
  	clust_index = dict_table_get_first_index(table);
  
  	/* Convert from index-specific column number to table-global
  	column number. */
  	col_no = dict_index_get_nth_col_no(clust_index, upd_field->field_no);
  
  	return(col_no == fts->doc_col);
  }
  /***********************************************************//**
  Checks if an FTS indexed column is affected by an UPDATE.
  @return offset within fts_t::indexes if FTS indexed column updated else
  ULINT_UNDEFINED */
  ulint
  row_upd_changes_fts_column(
  /*=======================*/
  	dict_table_t*	table,		/*!< in: table */
  	upd_field_t*	upd_field)	/*!< in: field to check */
  {
  	ulint		col_no;
  	dict_index_t*	clust_index;
  	fts_t*		fts = table->fts;
  
  	if (upd_fld_is_virtual_col(upd_field)) {
  		col_no = upd_field->field_no;
  		return(dict_table_is_fts_column(fts->indexes, col_no, true));
  	} else {
  		clust_index = dict_table_get_first_index(table);
  
  		/* Convert from index-specific column number to table-global
  		column number. */
  		col_no = dict_index_get_nth_col_no(clust_index,
  						   upd_field->field_no);
  		return(dict_table_is_fts_column(fts->indexes, col_no, false));
  	}
  
  }
  
  /***********************************************************//**
  Checks if an update vector changes some of the first ordering fields of an
  index record. This is only used in foreign key checks and we can assume
  that index does not contain column prefixes.
  @return TRUE if changes */
  static
  ibool
  row_upd_changes_first_fields_binary(
  /*================================*/
  	dtuple_t*	entry,	/*!< in: index entry */
  	dict_index_t*	index,	/*!< in: index of entry */
  	const upd_t*	update,	/*!< in: update vector for the row */
  	ulint		n)	/*!< in: how many first fields to check */
  {
  	ulint		n_upd_fields;
  	ulint		i, j;
  	dict_index_t*	clust_index;
  
  	ut_ad(update && index);
  	ut_ad(n <= dict_index_get_n_fields(index));
  
  	n_upd_fields = upd_get_n_fields(update);
  	clust_index = dict_table_get_first_index(index->table);
  
  	for (i = 0; i < n; i++) {
  
  		const dict_field_t*	ind_field;
  		const dict_col_t*	col;
  		ulint			col_pos;
  
  		ind_field = dict_index_get_nth_field(index, i);
  		col = dict_field_get_col(ind_field);
  		col_pos = dict_col_get_clust_pos(col, clust_index);
  
  		ut_a(ind_field->prefix_len == 0);
  
  		for (j = 0; j < n_upd_fields; j++) {
  
  			upd_field_t*	upd_field
  				= upd_get_nth_field(update, j);
  
  			if (col_pos == upd_field->field_no
  			    && !dfield_datas_are_binary_equal(
  				    dtuple_get_nth_field(entry, i),
  				    &upd_field->new_val, 0)) {
  
  				return(TRUE);
  			}
  		}
  	}
  
  	return(FALSE);
  }
  
  /*********************************************************************//**
  Copies the column values from a record. */
  UNIV_INLINE
  void
  row_upd_copy_columns(
  /*=================*/
  	rec_t*		rec,	/*!< in: record in a clustered index */
  	const ulint*	offsets,/*!< in: array returned by rec_get_offsets() */
  	sym_node_t*	column)	/*!< in: first column in a column list, or
  				NULL */
  {
  	byte*	data;
  	ulint	len;
  
  	while (column) {
  		data = rec_get_nth_field(rec, offsets,
  					 column->field_nos[SYM_CLUST_FIELD_NO],
  					 &len);
  		eval_node_copy_and_alloc_val(column, data, len);
  
  		column = UT_LIST_GET_NEXT(col_var_list, column);
  	}
  }
  
  /*********************************************************************//**
  Calculates the new values for fields to update. Note that row_upd_copy_columns
  must have been called first. */
  UNIV_INLINE
  void
  row_upd_eval_new_vals(
  /*==================*/
  	upd_t*	update)	/*!< in/out: update vector */
  {
  	que_node_t*	exp;
  	upd_field_t*	upd_field;
  	ulint		n_fields;
  	ulint		i;
  
  	n_fields = upd_get_n_fields(update);
  
  	for (i = 0; i < n_fields; i++) {
  		upd_field = upd_get_nth_field(update, i);
  
  		exp = upd_field->exp;
  
  		eval_exp(exp);
  
  		dfield_copy_data(&(upd_field->new_val), que_node_get_val(exp));
  	}
  }
  
  /** Stores to the heap the virtual columns that need for any indexes
  @param[in,out]	node		row update node
  @param[in]	update		an update vector if it is update
  @param[in]	thd		mysql thread handle
  @param[in,out]	mysql_table	mysql table object */
  static
  void
  row_upd_store_v_row(
  	upd_node_t*	node,
  	const upd_t*	update,
  	THD*		thd,
  	TABLE*		mysql_table)
  {
  	mem_heap_t*	heap = NULL;
  	dict_index_t*	index = dict_table_get_first_index(node->table);
  
  	for (ulint col_no = 0; col_no < dict_table_get_n_v_cols(node->table);
  	     col_no++) {
  
  		const dict_v_col_t*     col
  			= dict_table_get_nth_v_col(node->table, col_no);
  
  		if (col->m_col.ord_part) {
  			dfield_t*	dfield
  				= dtuple_get_nth_v_field(node->row, col_no);
  			ulint		n_upd
  				= update ? upd_get_n_fields(update) : 0;
  			ulint		i = 0;
  
  			/* Check if the value is already in update vector */
  			for (i = 0; i < n_upd; i++) {
  				const upd_field_t*      upd_field
  					= upd_get_nth_field(update, i);
  				if (!(upd_field->new_val.type.prtype
  				      & DATA_VIRTUAL)
  				    || upd_field->field_no != col->v_pos) {
  					continue;
  				}
  
  				dfield_copy_data(dfield, upd_field->old_v_val);
  				dfield_dup(dfield, node->heap);
  				break;
  			}
  
  			/* Not updated */
  			if (i >= n_upd) {
  				/* If this is an update, then the value
  				should be in update->old_vrow */
  				if (update) {
  					if (update->old_vrow == NULL) {
  						/* This only happens in
  						cascade update. And virtual
  						column can't be affected,
  						so it is Ok to set it to NULL */
  						dfield_set_null(dfield);
  					} else {
  						dfield_t*       vfield
  							= dtuple_get_nth_v_field(
  								update->old_vrow,
  								col_no);
  						dfield_copy_data(dfield, vfield);
  						dfield_dup(dfield, node->heap);
  					}
  				} else {
  					/* Need to compute, this happens when
  					deleting row */
  					innobase_get_computed_value(
  						node->row, col, index,
  						&heap, node->heap, NULL,
  						thd, mysql_table, NULL,
  						NULL, NULL);
  				}
  			}
  		}
  	}
  
  	if (heap) {
  		mem_heap_free(heap);
  	}
  }
  
  /** Stores to the heap the row on which the node->pcur is positioned.
  @param[in]	node		row update node
  @param[in]	thd		mysql thread handle
  @param[in,out]	mysql_table	NULL, or mysql table object when
  				user thread invokes dml */
  void
  row_upd_store_row(
  	upd_node_t*	node,
  	THD*		thd,
  	TABLE*		mysql_table)
  {
  	dict_index_t*	clust_index;
  	rec_t*		rec;
  	mem_heap_t*	heap		= NULL;
  	row_ext_t**	ext;
  	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
  	const ulint*	offsets;
  	rec_offs_init(offsets_);
  
  	ut_ad(node->pcur->latch_mode != BTR_NO_LATCHES);
  
  	if (node->row != NULL) {
  		mem_heap_empty(node->heap);
  	}
  
  	clust_index = dict_table_get_first_index(node->table);
  
  	rec = btr_pcur_get_rec(node->pcur);
  
  	offsets = rec_get_offsets(rec, clust_index, offsets_,
  				  ULINT_UNDEFINED, &heap);
  
  	if (dict_table_get_format(node->table) >= UNIV_FORMAT_B) {
  		/* In DYNAMIC or COMPRESSED format, there is no prefix
  		of externally stored columns in the clustered index
  		record. Build a cache of column prefixes. */
  		ext = &node->ext;
  	} else {
  		/* REDUNDANT and COMPACT formats store a local
  		768-byte prefix of each externally stored column.
  		No cache is needed. */
  		ext = NULL;
  		node->ext = NULL;
  	}
  
  	node->row = row_build(ROW_COPY_DATA, clust_index, rec, offsets,
  			      NULL, NULL, NULL, ext, node->heap);
  
  	if (node->table->n_v_cols) {
  		row_upd_store_v_row(node, node->is_delete ? NULL : node->update,
  				    thd, mysql_table);
  	}
  
  	if (node->is_delete) {
  		node->upd_row = NULL;
  		node->upd_ext = NULL;
  	} else {
  		node->upd_row = dtuple_copy(node->row, node->heap);
  		row_upd_replace(node->upd_row, &node->upd_ext,
  				clust_index, node->update, node->heap);
  	}
  
  	if (UNIV_LIKELY_NULL(heap)) {
  		mem_heap_free(heap);
  	}
  }
  
  /***********************************************************//**
  Print a MBR data from disk */
  static
  void
  srv_mbr_print(const byte* data)
  {
          double a, b, c, d;
          a = mach_double_read(data);
          data += sizeof(double);
          b = mach_double_read(data);
          data += sizeof(double);
          c = mach_double_read(data);
          data += sizeof(double);
          d = mach_double_read(data);
  
          ib::info() << "GIS MBR INFO: " << a << " and " << b << ", " << c
  		<< ", " << d << "\n";
  }
  
  
  /***********************************************************//**
  Updates a secondary index entry of a row.
  @return DB_SUCCESS if operation successfully completed, else error
  code or DB_LOCK_WAIT */
  static MY_ATTRIBUTE((warn_unused_result))
  dberr_t
  row_upd_sec_index_entry(
  /*====================*/
  	upd_node_t*	node,	/*!< in: row update node */
  	que_thr_t*	thr)	/*!< in: query thread */
  {
  	mtr_t			mtr;
  	const rec_t*		rec;
  	btr_pcur_t		pcur;
  	mem_heap_t*		heap;
  	dtuple_t*		entry;
  	dict_index_t*		index;
  	btr_cur_t*		btr_cur;
  	ibool			referenced;
  	dberr_t			err	= DB_SUCCESS;
  	trx_t*			trx	= thr_get_trx(thr);
  	ulint			mode;
  	ulint			flags = 0;
  	enum row_search_result	search_result;
  
  	ut_ad(trx->id != 0);
  
  	index = node->index;
  
  	referenced = row_upd_index_is_referenced(index, trx);
  
  	heap = mem_heap_create(1024);
  
  	/* Build old index entry */
  	entry = row_build_index_entry(node->row, node->ext, index, heap);
  	ut_a(entry);
  
  	if (!dict_table_is_intrinsic(index->table)) {
  		log_free_check();
  	}
  
  	DEBUG_SYNC_C_IF_THD(trx->mysql_thd,
  			    "before_row_upd_sec_index_entry");
  
  	mtr_start(&mtr);
  	mtr.set_named_space(index->space);
  
  	/* Disable REDO logging as lifetime of temp-tables is limited to
  	server or connection lifetime and so REDO information is not needed
  	on restart for recovery.
  	Disable locking as temp-tables are not shared across connection. */
  	if (dict_table_is_temporary(index->table)) {
  		flags |= BTR_NO_LOCKING_FLAG;
  		mtr.set_log_mode(MTR_LOG_NO_REDO);
  
  		if (dict_table_is_intrinsic(index->table)) {
  			flags |= BTR_NO_UNDO_LOG_FLAG;
  		}
  	}
  
  	if (!index->is_committed()) {
  		/* The index->online_status may change if the index is
  		or was being created online, but not committed yet. It
  		is protected by index->lock. */
  
  		mtr_s_lock(dict_index_get_lock(index), &mtr);
  
  		switch (dict_index_get_online_status(index)) {
  		case ONLINE_INDEX_COMPLETE:
  			/* This is a normal index. Do not log anything.
  			Perform the update on the index tree directly. */
  			break;
  		case ONLINE_INDEX_CREATION:
  			/* Log a DELETE and optionally INSERT. */
  			row_log_online_op(index, entry, 0);
  
  			if (!node->is_delete) {
  				mem_heap_empty(heap);
  				entry = row_build_index_entry(
  					node->upd_row, node->upd_ext,
  					index, heap);
  				ut_a(entry);
  				row_log_online_op(index, entry, trx->id);
  			}
  			/* fall through */
  		case ONLINE_INDEX_ABORTED:
  		case ONLINE_INDEX_ABORTED_DROPPED:
  			mtr_commit(&mtr);
  			goto func_exit;
  		}
  
  		/* We can only buffer delete-mark operations if there
  		are no foreign key constraints referring to the index.
  		Change buffering is disabled for temporary tables and
  		spatial index. */
  		mode = (referenced || dict_table_is_temporary(index->table)
  			|| dict_index_is_spatial(index))
  			? BTR_MODIFY_LEAF | BTR_ALREADY_S_LATCHED
  			: BTR_MODIFY_LEAF | BTR_ALREADY_S_LATCHED
  			| BTR_DELETE_MARK;
  	} else {
  		/* For secondary indexes,
  		index->online_status==ONLINE_INDEX_COMPLETE if
  		index->is_committed(). */
  		ut_ad(!dict_index_is_online_ddl(index));
  
  		/* We can only buffer delete-mark operations if there
  		are no foreign key constraints referring to the index.
  		Change buffering is disabled for temporary tables and
  		spatial index. */
  		mode = (referenced || dict_table_is_temporary(index->table)
  			|| dict_index_is_spatial(index))
  			? BTR_MODIFY_LEAF
  			: BTR_MODIFY_LEAF | BTR_DELETE_MARK;
  	}
  
  	if (dict_index_is_spatial(index)) {
  		ut_ad(mode & BTR_MODIFY_LEAF);
  		mode |= BTR_RTREE_DELETE_MARK;
  	}
  
  	/* Set the query thread, so that ibuf_insert_low() will be
  	able to invoke thd_get_trx(). */
  	btr_pcur_get_btr_cur(&pcur)->thr = thr;
  
  	search_result = row_search_index_entry(index, entry, mode,
  					       &pcur, &mtr);
  
  	btr_cur = btr_pcur_get_btr_cur(&pcur);
  
  	rec = btr_cur_get_rec(btr_cur);
  
  	switch (search_result) {
  	case ROW_NOT_DELETED_REF:	/* should only occur for BTR_DELETE */
  		ut_error;
  		break;
  	case ROW_BUFFERED:
  		/* Entry was delete marked already. */
  		break;
  
  	case ROW_NOT_FOUND:
  		if (!index->is_committed()) {
  			/* When online CREATE INDEX copied the update
  			that we already made to the clustered index,
  			and completed the secondary index creation
  			before we got here, the old secondary index
  			record would not exist. The CREATE INDEX
  			should be waiting for a MySQL meta-data lock
  			upgrade at least until this UPDATE returns.
  			After that point, set_committed(true) would be
  			invoked by commit_inplace_alter_table(). */
  			break;
  		}
  
  		if (dict_index_is_spatial(index) && btr_cur->rtr_info->fd_del) {
  			/* We found the record, but a delete marked */
  			break;
  		}
  
  		ib::error()
  			<< "Record in index " << index->name
  			<< " of table " << index->table->name
  			<< " was not found on update: " << *entry
  			<< " at: " << rec_index_print(rec, index);
  		srv_mbr_print((unsigned char*)entry->fields[0].data);
  #ifdef UNIV_DEBUG
  		mtr_commit(&mtr);
  		mtr_start(&mtr);
  		ut_ad(btr_validate_index(index, 0, false));
  		ut_ad(0);
  #endif /* UNIV_DEBUG */
  		break;
  	case ROW_FOUND:
  		ut_ad(err == DB_SUCCESS);
  
  		/* Delete mark the old index record; it can already be
  		delete marked if we return after a lock wait in
  		row_ins_sec_index_entry() below */
  		if (!rec_get_deleted_flag(
  			    rec, dict_table_is_comp(index->table))) {
  			err = btr_cur_del_mark_set_sec_rec(
  				flags, btr_cur, TRUE, thr, &mtr);
  			if (err != DB_SUCCESS) {
  				break;
  			}
  		}
  
  		ut_ad(err == DB_SUCCESS);
  
  		if (referenced) {
  
  			ulint*	offsets;
  
  			offsets = rec_get_offsets(
  				rec, index, NULL, ULINT_UNDEFINED,
  				&heap);
  
  			/* NOTE that the following call loses
  			the position of pcur ! */
  			err = row_upd_check_references_constraints(
  				node, &pcur, index->table,
  				index, offsets, thr, &mtr);
  		}
  		break;
  	}
  
  	btr_pcur_close(&pcur);
  	mtr_commit(&mtr);
  
  	if (node->is_delete || err != DB_SUCCESS) {
  
  		goto func_exit;
  	}
  
  	mem_heap_empty(heap);
  
  	/* Build a new index entry */
  	entry = row_build_index_entry(node->upd_row, node->upd_ext,
  				      index, heap);
  	ut_a(entry);
  
  	/* Insert new index entry */
  	err = row_ins_sec_index_entry(index, entry, thr, false);
  
  func_exit:
  	mem_heap_free(heap);
  
  	return(err);
  }
  
  /***********************************************************//**
  Updates the secondary index record if it is changed in the row update or
  deletes it if this is a delete.
  @return DB_SUCCESS if operation successfully completed, else error
  code or DB_LOCK_WAIT */
  static MY_ATTRIBUTE((warn_unused_result))
  dberr_t
  row_upd_sec_step(
  /*=============*/
  	upd_node_t*	node,	/*!< in: row update node */
  	que_thr_t*	thr)	/*!< in: query thread */
  {
  	ut_ad((node->state == UPD_NODE_UPDATE_ALL_SEC)
  	      || (node->state == UPD_NODE_UPDATE_SOME_SEC));
  	ut_ad(!dict_index_is_clust(node->index));
  
  	if (node->state == UPD_NODE_UPDATE_ALL_SEC
  	    || row_upd_changes_ord_field_binary(node->index, node->update,
  						thr, node->row, node->ext)) {
  		return(row_upd_sec_index_entry(node, thr));
  	}
  
  	return(DB_SUCCESS);
  }
  
  #ifdef UNIV_DEBUG
  # define row_upd_clust_rec_by_insert_inherit(rec,offsets,entry,update)	\
  	row_upd_clust_rec_by_insert_inherit_func(rec,offsets,entry,update)
  #else /* UNIV_DEBUG */
  # define row_upd_clust_rec_by_insert_inherit(rec,offsets,entry,update)	\
  	row_upd_clust_rec_by_insert_inherit_func(rec,entry,update)
  #endif /* UNIV_DEBUG */
  /*******************************************************************//**
  Mark non-updated off-page columns inherited when the primary key is
  updated. We must mark them as inherited in entry, so that they are not
  freed in a rollback. A limited version of this function used to be
  called btr_cur_mark_dtuple_inherited_extern().
  @return whether any columns were inherited */
  static
  bool
  row_upd_clust_rec_by_insert_inherit_func(
  /*=====================================*/
  	const rec_t*	rec,	/*!< in: old record, or NULL */
  #ifdef UNIV_DEBUG
  	const ulint*	offsets,/*!< in: rec_get_offsets(rec), or NULL */
  #endif /* UNIV_DEBUG */
  	dtuple_t*	entry,	/*!< in/out: updated entry to be
  				inserted into the clustered index */
  	const upd_t*	update)	/*!< in: update vector */
  {
  	bool	inherit	= false;
  	ulint	i;
  
  	ut_ad(!rec == !offsets);
  	ut_ad(!rec || rec_offs_any_extern(offsets));
  
  	for (i = 0; i < dtuple_get_n_fields(entry); i++) {
  		dfield_t*	dfield	= dtuple_get_nth_field(entry, i);
  		byte*		data;
  		ulint		len;
  
  		ut_ad(!offsets
  		      || !rec_offs_nth_extern(offsets, i)
  		      == !dfield_is_ext(dfield)
  		      || upd_get_field_by_field_no(update, i, false));
  		if (!dfield_is_ext(dfield)
  		    || upd_get_field_by_field_no(update, i, false)) {
  			continue;
  		}
  
  #ifdef UNIV_DEBUG
  		if (UNIV_LIKELY(rec != NULL)) {
  			const byte* rec_data
  				= rec_get_nth_field(rec, offsets, i, &len);
  			ut_ad(len == dfield_get_len(dfield));
  			ut_ad(len != UNIV_SQL_NULL);
  			ut_ad(len >= BTR_EXTERN_FIELD_REF_SIZE);
  
  			rec_data += len - BTR_EXTERN_FIELD_REF_SIZE;
  
  			/* The pointer must not be zero. */
  			ut_ad(memcmp(rec_data, field_ref_zero,
  				     BTR_EXTERN_FIELD_REF_SIZE));
  			/* The BLOB must be owned. */
  			ut_ad(!(rec_data[BTR_EXTERN_LEN]
  				& BTR_EXTERN_OWNER_FLAG));
  		}
  #endif /* UNIV_DEBUG */
  
  		len = dfield_get_len(dfield);
  		ut_a(len != UNIV_SQL_NULL);
  		ut_a(len >= BTR_EXTERN_FIELD_REF_SIZE);
  
  		data = static_cast<byte*>(dfield_get_data(dfield));
  
  		data += len - BTR_EXTERN_FIELD_REF_SIZE;
  		/* The pointer must not be zero. */
  		ut_a(memcmp(data, field_ref_zero, BTR_EXTERN_FIELD_REF_SIZE));
  
  		/* The BLOB must be owned, unless we are resuming from
  		a lock wait and we already had disowned the BLOB. */
  		ut_a(rec == NULL
  		     || !(data[BTR_EXTERN_LEN] & BTR_EXTERN_OWNER_FLAG));
  		data[BTR_EXTERN_LEN] &= ~BTR_EXTERN_OWNER_FLAG;
  		data[BTR_EXTERN_LEN] |= BTR_EXTERN_INHERITED_FLAG;
  		/* The BTR_EXTERN_INHERITED_FLAG only matters in
  		rollback of a fresh insert (insert_undo log).
  		Purge (operating on update_undo log) will always free
  		the extern fields of a delete-marked row. */
  
  		inherit = true;
  	}
  
  	return(inherit);
  }
  
  /***********************************************************//**
  Marks the clustered index record deleted and inserts the updated version
  of the record to the index. This function should be used when the ordering
  fields of the clustered index record change. This should be quite rare in
  database applications.
  @return DB_SUCCESS if operation successfully completed, else error
  code or DB_LOCK_WAIT */
  static MY_ATTRIBUTE((warn_unused_result))
  dberr_t
  row_upd_clust_rec_by_insert(
  /*========================*/
  	ulint		flags,  /*!< in: undo logging and locking flags */
  	upd_node_t*	node,	/*!< in/out: row update node */
  	dict_index_t*	index,	/*!< in: clustered index of the record */
  	que_thr_t*	thr,	/*!< in: query thread */
  	ibool		referenced,/*!< in: TRUE if index may be referenced in
  				a foreign key constraint */
  	mtr_t*		mtr)	/*!< in/out: mtr; gets committed here */
  {
  	mem_heap_t*	heap;
  	btr_pcur_t*	pcur;
  	btr_cur_t*	btr_cur;
  	trx_t*		trx;
  	dict_table_t*	table;
  	dtuple_t*	entry;
  	dberr_t		err;
  	rec_t*		rec;
  	ulint*		offsets			= NULL;
  
  	ut_ad(node);
  	ut_ad(dict_index_is_clust(index));
  
  	trx = thr_get_trx(thr);
  	table = node->table;
  	pcur = node->pcur;
  	btr_cur	= btr_pcur_get_btr_cur(pcur);
  
  	heap = mem_heap_create(1000);
  
  	entry = row_build_index_entry_low(node->upd_row, node->upd_ext,
  					  index, heap, ROW_BUILD_FOR_INSERT);
  	ut_ad(dtuple_get_info_bits(entry) == 0);
  
  	row_upd_index_entry_sys_field(entry, index, DATA_TRX_ID, trx->id);
  
  	switch (node->state) {
  	default:
  		ut_error;
  	case UPD_NODE_INSERT_CLUSTERED:
  		/* A lock wait occurred in row_ins_clust_index_entry() in
  		the previous invocation of this function. */
  		row_upd_clust_rec_by_insert_inherit(
  			NULL, NULL, entry, node->update);
  		break;
  	case UPD_NODE_UPDATE_CLUSTERED:
  		/* This is the first invocation of the function where
  		we update the primary key.  Delete-mark the old record
  		in the clustered index and prepare to insert a new entry. */
  		rec = btr_cur_get_rec(btr_cur);
  		offsets = rec_get_offsets(rec, index, NULL,
  					  ULINT_UNDEFINED, &heap);
  		ut_ad(page_rec_is_user_rec(rec));
  
  		if (rec_get_deleted_flag(rec, rec_offs_comp(offsets))) {
  			/* If the clustered index record is already delete
  			marked, then we are here after a DB_LOCK_WAIT.
  			Skip delete marking clustered index and disowning
  			its blobs. */
  			ut_ad(rec_get_trx_id(rec, index) == trx->id);
  			ut_ad(!trx_undo_roll_ptr_is_insert(
  			              row_get_rec_roll_ptr(rec, index,
  							   offsets)));
  			goto check_fk;
  		}
  
  		err = btr_cur_del_mark_set_clust_rec(
  			flags, btr_cur_get_block(btr_cur), rec, index, offsets,
  			thr, node->row, mtr);
  		if (err != DB_SUCCESS) {
  err_exit:
  			mtr_commit(mtr);
  			mem_heap_free(heap);
  			return(err);
  		}
  
  		/* If the the new row inherits externally stored
  		fields (off-page columns a.k.a. BLOBs) from the
  		delete-marked old record, mark them disowned by the
  		old record and owned by the new entry. */
  
  		if (rec_offs_any_extern(offsets)) {
  			if (row_upd_clust_rec_by_insert_inherit(
  				    rec, offsets, entry, node->update)) {
  				/* The blobs are disowned here, expecting the
  				insert down below to inherit them.  But if the
  				insert fails, then this disown will be undone
  				when the operation is rolled back. */
  				btr_cur_disown_inherited_fields(
  					btr_cur_get_page_zip(btr_cur),
  					rec, index, offsets, node->update,
  					mtr);
  			}
  		}
  check_fk:
  		if (referenced) {
  			/* NOTE that the following call loses
  			the position of pcur ! */
  
  			err = row_upd_check_references_constraints(
  				node, pcur, table, index, offsets, thr, mtr);
  
  			if (err != DB_SUCCESS) {
  				goto err_exit;
  			}
  		}
  	}
  
  	mtr_commit(mtr);
  
  	err = row_ins_clust_index_entry(
  		index, entry, thr,
  		node->upd_ext ? node->upd_ext->n_ext : 0, false);
  	node->state = UPD_NODE_INSERT_CLUSTERED;
  
  	mem_heap_free(heap);
  
  	return(err);
  }
  
  /***********************************************************//**
  Updates a clustered index record of a row when the ordering fields do
  not change.
  @return DB_SUCCESS if operation successfully completed, else error
  code or DB_LOCK_WAIT */
  static MY_ATTRIBUTE((warn_unused_result))
  dberr_t
  row_upd_clust_rec(
  /*==============*/
  	ulint		flags,  /*!< in: undo logging and locking flags */
  	upd_node_t*	node,	/*!< in: row update node */
  	dict_index_t*	index,	/*!< in: clustered index */
  	ulint*		offsets,/*!< in: rec_get_offsets() on node->pcur */
  	mem_heap_t**	offsets_heap,
  				/*!< in/out: memory heap, can be emptied */
  	que_thr_t*	thr,	/*!< in: query thread */
  	mtr_t*		mtr)	/*!< in: mtr; gets committed here */
  {
  	mem_heap_t*	heap		= NULL;
  	big_rec_t*	big_rec		= NULL;
  	btr_pcur_t*	pcur;
  	btr_cur_t*	btr_cur;
  	dberr_t		err;
  	const dtuple_t*	rebuilt_old_pk	= NULL;
  
  	ut_ad(node);
  	ut_ad(dict_index_is_clust(index));
  	ut_ad(!thr_get_trx(thr)->in_rollback);
  
  	pcur = node->pcur;
  	btr_cur = btr_pcur_get_btr_cur(pcur);
  
  	ut_ad(btr_cur_get_index(btr_cur) == index);
  	ut_ad(!rec_get_deleted_flag(btr_cur_get_rec(btr_cur),
  				    dict_table_is_comp(index->table)));
  	ut_ad(rec_offs_validate(btr_cur_get_rec(btr_cur), index, offsets));
  
  	if (dict_index_is_online_ddl(index)) {
  		rebuilt_old_pk = row_log_table_get_pk(
  			btr_cur_get_rec(btr_cur), index, offsets, NULL, &heap);
  	}
  
  	/* Try optimistic updating of the record, keeping changes within
  	the page; we do not check locks because we assume the x-lock on the
  	record to update */
  
  	if (node->cmpl_info & UPD_NODE_NO_SIZE_CHANGE) {
  		err = btr_cur_update_in_place(
  			flags | BTR_NO_LOCKING_FLAG, btr_cur,
  			offsets, node->update,
  			node->cmpl_info, thr, thr_get_trx(thr)->id, mtr);
  	} else {
  		err = btr_cur_optimistic_update(
  			flags | BTR_NO_LOCKING_FLAG, btr_cur,
  			&offsets, offsets_heap, node->update,
  			node->cmpl_info, thr, thr_get_trx(thr)->id, mtr);
  	}
  
  	if (err == DB_SUCCESS) {
  		goto success;
  	}
  
  	mtr_commit(mtr);
  
  	if (buf_LRU_buf_pool_running_out()) {
  
  		err = DB_LOCK_TABLE_FULL;
  		goto func_exit;
  	}
  	/* We may have to modify the tree structure: do a pessimistic descent
  	down the index tree */
  
  	mtr_start(mtr);
  	mtr->set_named_space(index->space);
  
  	/* Disable REDO logging as lifetime of temp-tables is limited to
  	server or connection lifetime and so REDO information is not needed
  	on restart for recovery.
  	Disable locking as temp-tables are not shared across connection. */
  	if (dict_table_is_temporary(index->table)) {
  		flags |= BTR_NO_LOCKING_FLAG;
  		mtr->set_log_mode(MTR_LOG_NO_REDO);
  
  		if (dict_table_is_intrinsic(index->table)) {
  			flags |= BTR_NO_UNDO_LOG_FLAG;
  		}
  	}
  
  	/* NOTE: this transaction has an s-lock or x-lock on the record and
  	therefore other transactions cannot modify the record when we have no
  	latch on the page. In addition, we assume that other query threads of
  	the same transaction do not modify the record in the meantime.
  	Therefore we can assert that the restoration of the cursor succeeds. */
  
  	ut_a(btr_pcur_restore_position(BTR_MODIFY_TREE, pcur, mtr));
  
  	ut_ad(!rec_get_deleted_flag(btr_pcur_get_rec(pcur),
  				    dict_table_is_comp(index->table)));
  
  	if (!heap) {
  		heap = mem_heap_create(1024);
  	}
  
  	err = btr_cur_pessimistic_update(
  		flags | BTR_NO_LOCKING_FLAG | BTR_KEEP_POS_FLAG, btr_cur,
  		&offsets, offsets_heap, heap, &big_rec,
  		node->update, node->cmpl_info,
  		thr, thr_get_trx(thr)->id, mtr);
  	if (big_rec) {
  		ut_a(err == DB_SUCCESS);
  
  		DEBUG_SYNC_C("before_row_upd_extern");
  		err = btr_store_big_rec_extern_fields(
  			pcur, node->update, offsets, big_rec, mtr,
  			BTR_STORE_UPDATE);
  		DEBUG_SYNC_C("after_row_upd_extern");
  	}
  
  	if (err == DB_SUCCESS) {
  success:
  		if (dict_index_is_online_ddl(index)) {
  			dtuple_t*	new_v_row = NULL;
  			dtuple_t*	old_v_row = NULL;
  
  			if (!(node->cmpl_info & UPD_NODE_NO_ORD_CHANGE)) {
  				new_v_row = node->upd_row;
  				old_v_row = node->update->old_vrow;
  			}
  
  			row_log_table_update(
  				btr_cur_get_rec(btr_cur),
  				index, offsets, rebuilt_old_pk, new_v_row,
  				old_v_row);
  		}
  	}
  
  	mtr_commit(mtr);
  func_exit:
  	if (heap) {
  		mem_heap_free(heap);
  	}
  
  	if (big_rec) {
  		dtuple_big_rec_free(big_rec);
  	}
  
  	return(err);
  }
  
  /***********************************************************//**
  Delete marks a clustered index record.
  @return DB_SUCCESS if operation successfully completed, else error code */
  static MY_ATTRIBUTE((warn_unused_result))
  dberr_t
  row_upd_del_mark_clust_rec(
  /*=======================*/
  	ulint		flags,  /*!< in: undo logging and locking flags */
  	upd_node_t*	node,	/*!< in: row update node */
  	dict_index_t*	index,	/*!< in: clustered index */
  	ulint*		offsets,/*!< in/out: rec_get_offsets() for the
  				record under the cursor */
  	que_thr_t*	thr,	/*!< in: query thread */
  	ibool		referenced,
  				/*!< in: TRUE if index may be referenced in
  				a foreign key constraint */
  	mtr_t*		mtr)	/*!< in: mtr; gets committed here */
  {
  	btr_pcur_t*	pcur;
  	btr_cur_t*	btr_cur;
  	dberr_t		err;
  
  	ut_ad(node);
  	ut_ad(dict_index_is_clust(index));
  	ut_ad(node->is_delete);
  
  	pcur = node->pcur;
  	btr_cur = btr_pcur_get_btr_cur(pcur);
  
  	/* Store row because we have to build also the secondary index
  	entries */
  
  	row_upd_store_row(node, thr_get_trx(thr)->mysql_thd,
  			  thr->prebuilt ? thr->prebuilt->m_mysql_table : NULL);
  
  	/* Mark the clustered index record deleted; we do not have to check
  	locks, because we assume that we have an x-lock on the record */
  
  	err = btr_cur_del_mark_set_clust_rec(
  		flags, btr_cur_get_block(btr_cur), btr_cur_get_rec(btr_cur),
  		index, offsets, thr, node->row, mtr);
  	if (err == DB_SUCCESS && referenced) {
  		/* NOTE that the following call loses the position of pcur ! */
  
  		err = row_upd_check_references_constraints(
  			node, pcur, index->table, index, offsets, thr, mtr);
  	}
  
  	mtr_commit(mtr);
  
  	return(err);
  }
  
  /***********************************************************//**
  Updates the clustered index record.
  @return DB_SUCCESS if operation successfully completed, DB_LOCK_WAIT
  in case of a lock wait, else error code */
  static MY_ATTRIBUTE((warn_unused_result))
  dberr_t
  row_upd_clust_step(
  /*===============*/
  	upd_node_t*	node,	/*!< in: row update node */
  	que_thr_t*	thr)	/*!< in: query thread */
  {
  	dict_index_t*	index;
  	btr_pcur_t*	pcur;
  	ibool		success;
  	dberr_t		err;
  	mtr_t		mtr;
  	rec_t*		rec;
  	mem_heap_t*	heap	= NULL;
  	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
  	ulint*		offsets;
  	ibool		referenced;
  	ulint		flags	= 0;
  	trx_t*		trx = thr_get_trx(thr);
  	rec_offs_init(offsets_);
  
  	index = dict_table_get_first_index(node->table);
  
  	referenced = row_upd_index_is_referenced(index, trx);
  
  	pcur = node->pcur;
  
  	/* We have to restore the cursor to its position */
  
  	mtr_start(&mtr);
  	mtr.set_named_space(index->space);
  
  	/* Disable REDO logging as lifetime of temp-tables is limited to
  	server or connection lifetime and so REDO information is not needed
  	on restart for recovery.
  	Disable locking as temp-tables are not shared across connection. */
  	if (dict_table_is_temporary(index->table)) {
  		flags |= BTR_NO_LOCKING_FLAG;
  		mtr.set_log_mode(MTR_LOG_NO_REDO);
  
  		if (dict_table_is_intrinsic(index->table)) {
  			flags |= BTR_NO_UNDO_LOG_FLAG;
  		}
  	}
  
  	/* If the restoration does not succeed, then the same
  	transaction has deleted the record on which the cursor was,
  	and that is an SQL error. If the restoration succeeds, it may
  	still be that the same transaction has successively deleted
  	and inserted a record with the same ordering fields, but in
  	that case we know that the transaction has at least an
  	implicit x-lock on the record. */
  
  	ut_a(pcur->rel_pos == BTR_PCUR_ON);
  
  	ulint	mode;
  
  	DEBUG_SYNC_C_IF_THD(
  		thr_get_trx(thr)->mysql_thd,
  		"innodb_row_upd_clust_step_enter");
  
  	if (dict_index_is_online_ddl(index)) {
  		ut_ad(node->table->id != DICT_INDEXES_ID);
  		mode = BTR_MODIFY_LEAF | BTR_ALREADY_S_LATCHED;
  		mtr_s_lock(dict_index_get_lock(index), &mtr);
  	} else {
  		mode = BTR_MODIFY_LEAF;
  	}
  
  	success = btr_pcur_restore_position(mode, pcur, &mtr);
  
  	if (!success) {
  		err = DB_RECORD_NOT_FOUND;
  
  		mtr_commit(&mtr);
  
  		return(err);
  	}
  
  	/* If this is a row in SYS_INDEXES table of the data dictionary,
  	then we have to free the file segments of the index tree associated
  	with the index */
  
  	if (node->is_delete && node->table->id == DICT_INDEXES_ID) {
  
  		ut_ad(!dict_index_is_online_ddl(index));
  
  		dict_drop_index_tree(
  			btr_pcur_get_rec(pcur), pcur, &mtr);
  
  		mtr_commit(&mtr);
  
  		mtr_start(&mtr);
  		mtr.set_named_space(index->space);
  
  		success = btr_pcur_restore_position(BTR_MODIFY_LEAF, pcur,
  						    &mtr);
  		if (!success) {
  			err = DB_ERROR;
  
  			mtr_commit(&mtr);
  
  			return(err);
  		}
  	}
  
  	rec = btr_pcur_get_rec(pcur);
  	offsets = rec_get_offsets(rec, index, offsets_,
  				  ULINT_UNDEFINED, &heap);
  
  	if (!node->has_clust_rec_x_lock) {
  		err = lock_clust_rec_modify_check_and_lock(
  			flags, btr_pcur_get_block(pcur),
  			rec, index, offsets, thr);
  		if (err != DB_SUCCESS) {
  			mtr_commit(&mtr);
  			goto exit_func;
  		}
  	}
  
  	ut_ad(lock_trx_has_rec_x_lock(thr_get_trx(thr), index->table,
  				      btr_pcur_get_block(pcur),
  				      page_rec_get_heap_no(rec)));
  
  	/* NOTE: the following function calls will also commit mtr */
  
  	if (node->is_delete) {
  		err = row_upd_del_mark_clust_rec(
  			flags, node, index, offsets, thr, referenced, &mtr);
  
  		if (err == DB_SUCCESS) {
  			node->state = UPD_NODE_UPDATE_ALL_SEC;
  			node->index = dict_table_get_next_index(index);
  		}
  
  		goto exit_func;
  	}
  
  	/* If the update is made for MySQL, we already have the update vector
  	ready, else we have to do some evaluation: */
  
  	if (UNIV_UNLIKELY(!node->in_mysql_interface)) {
  		/* Copy the necessary columns from clust_rec and calculate the
  		new values to set */
  		row_upd_copy_columns(rec, offsets,
  				     UT_LIST_GET_FIRST(node->columns));
  		row_upd_eval_new_vals(node->update);
  	}
  
  	if (node->cmpl_info & UPD_NODE_NO_ORD_CHANGE) {
  
  		err = row_upd_clust_rec(
  			flags, node, index, offsets, &heap, thr, &mtr);
  		goto exit_func;
  	}
  
  	row_upd_store_row(node, trx->mysql_thd,
  			  thr->prebuilt ? thr->prebuilt->m_mysql_table : NULL);
  
  	if (row_upd_changes_ord_field_binary(index, node->update, thr,
  					     node->row, node->ext)) {
  
  		/* Update causes an ordering field (ordering fields within
  		the B-tree) of the clustered index record to change: perform
  		the update by delete marking and inserting.
  
  		TODO! What to do to the 'Halloween problem', where an update
  		moves the record forward in index so that it is again
  		updated when the cursor arrives there? Solution: the
  		read operation must check the undo record undo number when
  		choosing records to update. MySQL solves now the problem
  		externally! */
  
  		err = row_upd_clust_rec_by_insert(
  			flags, node, index, thr, referenced, &mtr);
  
  		if (err != DB_SUCCESS) {
  
  			goto exit_func;
  		}
  
  		node->state = UPD_NODE_UPDATE_ALL_SEC;
  	} else {
  		err = row_upd_clust_rec(
  			flags, node, index, offsets, &heap, thr, &mtr);
  
  		if (err != DB_SUCCESS) {
  
  			goto exit_func;
  		}
  
  		node->state = UPD_NODE_UPDATE_SOME_SEC;
  	}
  
  	node->index = dict_table_get_next_index(index);
  
  exit_func:
  	if (heap) {
  		mem_heap_free(heap);
  	}
  	return(err);
  }
  
  /***********************************************************//**
  Updates the affected index records of a row. When the control is transferred
  to this node, we assume that we have a persistent cursor which was on a
  record, and the position of the cursor is stored in the cursor.
  @return DB_SUCCESS if operation successfully completed, else error
  code or DB_LOCK_WAIT */
  dberr_t
  row_upd(
  /*====*/
  	upd_node_t*	node,	/*!< in: row update node */
  	que_thr_t*	thr)	/*!< in: query thread */
  {
  	dberr_t		err	= DB_SUCCESS;
  	DBUG_ENTER("row_upd");
  
  	ut_ad(node != NULL);
  	ut_ad(thr != NULL);
  	ut_ad(!thr_get_trx(thr)->in_rollback);
  
  	DBUG_PRINT("row_upd", ("table: %s", node->table->name.m_name));
  	DBUG_PRINT("row_upd", ("info bits in update vector: 0x%lx",
  			       node->update ? node->update->info_bits: 0));
  	DBUG_PRINT("row_upd", ("foreign_id: %s",
  			       node->foreign ? node->foreign->id: "NULL"));
  
  	if (UNIV_LIKELY(node->in_mysql_interface)) {
  
  		/* We do not get the cmpl_info value from the MySQL
  		interpreter: we must calculate it on the fly: */
  
  		if (node->is_delete
  		    || row_upd_changes_some_index_ord_field_binary(
  			    node->table, node->update)) {
  			node->cmpl_info = 0;
  		} else {
  			node->cmpl_info = UPD_NODE_NO_ORD_CHANGE;
  		}
  	}
  
  	switch (node->state) {
  	case UPD_NODE_UPDATE_CLUSTERED:
  	case UPD_NODE_INSERT_CLUSTERED:
  		if (!dict_table_is_intrinsic(node->table)) {
  			log_free_check();
  		}
  		err = row_upd_clust_step(node, thr);
  
  		if (err != DB_SUCCESS) {
  
  			DBUG_RETURN(err);
  		}
  	}
  
  	DEBUG_SYNC_C_IF_THD(thr_get_trx(thr)->mysql_thd,
  			    "after_row_upd_clust");
  
  	if (node->index == NULL
  	    || (!node->is_delete
  		&& (node->cmpl_info & UPD_NODE_NO_ORD_CHANGE))) {
  
  		DBUG_RETURN(DB_SUCCESS);
  	}
  
  	DBUG_EXECUTE_IF("row_upd_skip_sec", node->index = NULL;);
  
  	do {
  		/* Skip corrupted index */
  		dict_table_skip_corrupt_index(node->index);
  
  		if (!node->index) {
  			break;
  		}
  
  		if (node->index->type != DICT_FTS) {
  			err = row_upd_sec_step(node, thr);
  
  			if (err != DB_SUCCESS) {
  
  				DBUG_RETURN(err);
  			}
  		}
  
  		node->index = dict_table_get_next_index(node->index);
  	} while (node->index != NULL);
  
  	ut_ad(err == DB_SUCCESS);
  
  	/* Do some cleanup */
  
  	if (node->row != NULL) {
  		node->row = NULL;
  		node->ext = NULL;
  		node->upd_row = NULL;
  		node->upd_ext = NULL;
  		mem_heap_empty(node->heap);
  	}
  
  	node->state = UPD_NODE_UPDATE_CLUSTERED;
  
  	DBUG_RETURN(err);
  }
  
  /***********************************************************//**
  Updates a row in a table. This is a high-level function used in SQL execution
  graphs.
  @return query thread to run next or NULL */
  que_thr_t*
  row_upd_step(
  /*=========*/
  	que_thr_t*	thr)	/*!< in: query thread */
  {
  	upd_node_t*	node;
  	sel_node_t*	sel_node;
  	que_node_t*	parent;
  	dberr_t		err		= DB_SUCCESS;
  	trx_t*		trx;
  	DBUG_ENTER("row_upd_step");
  
  	ut_ad(thr);
  
  	trx = thr_get_trx(thr);
  
  	trx_start_if_not_started_xa(trx, true);
  
  	node = static_cast<upd_node_t*>(thr->run_node);
  
  	sel_node = node->select;
  
  	parent = que_node_get_parent(node);
  
  	ut_ad(que_node_get_type(node) == QUE_NODE_UPDATE);
  
  	if (thr->prev_node == parent) {
  		node->state = UPD_NODE_SET_IX_LOCK;
  	}
  
  	if (node->state == UPD_NODE_SET_IX_LOCK) {
  
  		if (!node->has_clust_rec_x_lock) {
  			/* It may be that the current session has not yet
  			started its transaction, or it has been committed: */
  
  			err = lock_table(0, node->table, LOCK_IX, thr);
  
  			if (err != DB_SUCCESS) {
  
  				goto error_handling;
  			}
  		}
  
  		node->state = UPD_NODE_UPDATE_CLUSTERED;
  
  		if (node->searched_update) {
  			/* Reset the cursor */
  			sel_node->state = SEL_NODE_OPEN;
  
  			/* Fetch a row to update */
  
  			thr->run_node = sel_node;
  
  			DBUG_RETURN(thr);
  		}
  	}
  
  	/* sel_node is NULL if we are in the MySQL interface */
  
  	if (sel_node && (sel_node->state != SEL_NODE_FETCH)) {
  
  		if (!node->searched_update) {
  			/* An explicit cursor should be positioned on a row
  			to update */
  
  			ut_error;
  
  			err = DB_ERROR;
  
  			goto error_handling;
  		}
  
  		ut_ad(sel_node->state == SEL_NODE_NO_MORE_ROWS);
  
  		/* No more rows to update, or the select node performed the
  		updates directly in-place */
  
  		thr->run_node = parent;
  
  		DBUG_RETURN(thr);
  	}
  
  	/* DO THE CHECKS OF THE CONSISTENCY CONSTRAINTS HERE */
  
  	err = row_upd(node, thr);
  
  error_handling:
  	trx->error_state = err;
  
  	if (err != DB_SUCCESS) {
  		DBUG_RETURN(NULL);
  	}
  
  	/* DO THE TRIGGER ACTIONS HERE */
  
  	if (node->searched_update) {
  		/* Fetch next row to update */
  
  		thr->run_node = sel_node;
  	} else {
  		/* It was an explicit cursor update */
  
  		thr->run_node = parent;
  	}
  
  	node->state = UPD_NODE_UPDATE_CLUSTERED;
  
  	DBUG_RETURN(thr);
  }
  
  #endif /* !UNIV_HOTBACKUP */
   