xref: /dports/databases/mariadb105-server/mariadb-10.5.15/storage/innobase/row/row0mysql.cc

/*****************************************************************************

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2015, 2021, MariaDB Corporation.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
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, Fifth Floor, Boston, MA 02110-1335 USA

*****************************************************************************/

/**************************************************//**
@file row/row0mysql.cc
Interface between Innobase row operations and MySQL.
Contains also create table and other data dictionary operations.

Created 9/17/2000 Heikki Tuuri
*******************************************************/

#include "univ.i"
#include <debug_sync.h>
#include <gstream.h>
#include <spatial.h>

#include "row0mysql.h"
#include "btr0sea.h"
#include "dict0boot.h"
#include "dict0crea.h"
#include "dict0dict.h"
#include "dict0load.h"
#include "dict0priv.h"
#include "dict0stats.h"
#include "dict0stats_bg.h"
#include "dict0defrag_bg.h"
#include "btr0defragment.h"
#include "fil0fil.h"
#include "fil0crypt.h"
#include "fsp0file.h"
#include "fts0fts.h"
#include "fts0types.h"
#include "ibuf0ibuf.h"
#include "lock0lock.h"
#include "log0log.h"
#include "pars0pars.h"
#include "que0que.h"
#include "rem0cmp.h"
#include "row0import.h"
#include "row0ins.h"
#include "row0row.h"
#include "row0sel.h"
#include "row0upd.h"
#include "trx0purge.h"
#include "trx0rec.h"
#include "trx0roll.h"
#include "trx0undo.h"
#include "srv0start.h"
#include "row0ext.h"
#include "srv0start.h"

#include <algorithm>
#include <deque>
#include <vector>

#ifdef WITH_WSREP
#include "mysql/service_wsrep.h"
#include "wsrep.h"
#include "log.h"
#include "wsrep_mysqld.h"
#endif

/** Provide optional 4.x backwards compatibility for 5.0 and above */
ibool	row_rollback_on_timeout	= FALSE;

/** Chain node of the list of tables to drop in the background. */
struct row_mysql_drop_t{
	table_id_t			table_id;	/*!< table id */
	UT_LIST_NODE_T(row_mysql_drop_t)row_mysql_drop_list;
							/*!< list chain node */
};

/** @brief List of tables we should drop in background.

ALTER TABLE in MySQL requires that the table handler can drop the
table in background when there are no queries to it any
more.  Protected by row_drop_list_mutex. */
static UT_LIST_BASE_NODE_T(row_mysql_drop_t)	row_mysql_drop_list;

/** Mutex protecting the background table drop list. */
static ib_mutex_t row_drop_list_mutex;

/** Flag: has row_mysql_drop_list been initialized? */
static bool row_mysql_drop_list_inited;

#ifdef UNIV_DEBUG
/** Wait for the background drop list to become empty. */
void
row_wait_for_background_drop_list_empty()
{
	bool	empty = false;
	while (!empty) {
		mutex_enter(&row_drop_list_mutex);
		empty = (UT_LIST_GET_LEN(row_mysql_drop_list) == 0);
		mutex_exit(&row_drop_list_mutex);
		os_thread_sleep(100000);
	}
}
#endif /* UNIV_DEBUG */

/*******************************************************************//**
Delays an INSERT, DELETE or UPDATE operation if the purge is lagging. */
static
void
row_mysql_delay_if_needed(void)
/*===========================*/
{
	if (srv_dml_needed_delay) {
		os_thread_sleep(srv_dml_needed_delay);
	}
}

/*******************************************************************//**
Frees the blob heap in prebuilt when no longer needed. */
void
row_mysql_prebuilt_free_blob_heap(
/*==============================*/
	row_prebuilt_t*	prebuilt)	/*!< in: prebuilt struct of a
					ha_innobase:: table handle */
{
	DBUG_ENTER("row_mysql_prebuilt_free_blob_heap");

	DBUG_PRINT("row_mysql_prebuilt_free_blob_heap",
		   ("blob_heap freeing: %p", prebuilt->blob_heap));

	mem_heap_free(prebuilt->blob_heap);
	prebuilt->blob_heap = NULL;
	DBUG_VOID_RETURN;
}

/*******************************************************************//**
Stores a >= 5.0.3 format true VARCHAR length to dest, in the MySQL row
format.
@return pointer to the data, we skip the 1 or 2 bytes at the start
that are used to store the len */
byte*
row_mysql_store_true_var_len(
/*=========================*/
	byte*	dest,	/*!< in: where to store */
	ulint	len,	/*!< in: length, must fit in two bytes */
	ulint	lenlen)	/*!< in: storage length of len: either 1 or 2 bytes */
{
	if (lenlen == 2) {
		ut_a(len < 256 * 256);

		mach_write_to_2_little_endian(dest, len);

		return(dest + 2);
	}

	ut_a(lenlen == 1);
	ut_a(len < 256);

	mach_write_to_1(dest, len);

	return(dest + 1);
}

/*******************************************************************//**
Reads a >= 5.0.3 format true VARCHAR length, in the MySQL row format, and
returns a pointer to the data.
@return pointer to the data, we skip the 1 or 2 bytes at the start
that are used to store the len */
const byte*
row_mysql_read_true_varchar(
/*========================*/
	ulint*		len,	/*!< out: variable-length field length */
	const byte*	field,	/*!< in: field in the MySQL format */
	ulint		lenlen)	/*!< in: storage length of len: either 1
				or 2 bytes */
{
	if (lenlen == 2) {
		*len = mach_read_from_2_little_endian(field);

		return(field + 2);
	}

	ut_a(lenlen == 1);

	*len = mach_read_from_1(field);

	return(field + 1);
}

/*******************************************************************//**
Stores a reference to a BLOB in the MySQL format. */
void
row_mysql_store_blob_ref(
/*=====================*/
	byte*		dest,	/*!< in: where to store */
	ulint		col_len,/*!< in: dest buffer size: determines into
				how many bytes the BLOB length is stored,
				the space for the length may vary from 1
				to 4 bytes */
	const void*	data,	/*!< in: BLOB data; if the value to store
				is SQL NULL this should be NULL pointer */
	ulint		len)	/*!< in: BLOB length; if the value to store
				is SQL NULL this should be 0; remember
				also to set the NULL bit in the MySQL record
				header! */
{
	/* MySQL might assume the field is set to zero except the length and
	the pointer fields */

	memset(dest, '\0', col_len);

	/* In dest there are 1 - 4 bytes reserved for the BLOB length,
	and after that 8 bytes reserved for the pointer to the data.
	In 32-bit architectures we only use the first 4 bytes of the pointer
	slot. */

	ut_a(col_len - 8 > 1 || len < 256);
	ut_a(col_len - 8 > 2 || len < 256 * 256);
	ut_a(col_len - 8 > 3 || len < 256 * 256 * 256);

	mach_write_to_n_little_endian(dest, col_len - 8, len);

	memcpy(dest + col_len - 8, &data, sizeof data);
}

/*******************************************************************//**
Reads a reference to a BLOB in the MySQL format.
@return pointer to BLOB data */
const byte*
row_mysql_read_blob_ref(
/*====================*/
	ulint*		len,		/*!< out: BLOB length */
	const byte*	ref,		/*!< in: BLOB reference in the
					MySQL format */
	ulint		col_len)	/*!< in: BLOB reference length
					(not BLOB length) */
{
	byte*	data;

	*len = mach_read_from_n_little_endian(ref, col_len - 8);

	memcpy(&data, ref + col_len - 8, sizeof data);

	return(data);
}

/*******************************************************************//**
Converting InnoDB geometry data format to MySQL data format. */
void
row_mysql_store_geometry(
/*=====================*/
	byte*		dest,		/*!< in/out: where to store */
	ulint		dest_len,	/*!< in: dest buffer size: determines
					into how many bytes the GEOMETRY length
					is stored, the space for the length
					may vary from 1 to 4 bytes */
	const byte*	src,		/*!< in: GEOMETRY data; if the value to
					store is SQL NULL this should be NULL
					pointer */
	ulint		src_len)	/*!< in: GEOMETRY length; if the value
					to store is SQL NULL this should be 0;
					remember also to set the NULL bit in
					the MySQL record header! */
{
	/* MySQL might assume the field is set to zero except the length and
	the pointer fields */
	MEM_CHECK_DEFINED(src, src_len);

	memset(dest, '\0', dest_len);

	/* In dest there are 1 - 4 bytes reserved for the BLOB length,
	and after that 8 bytes reserved for the pointer to the data.
	In 32-bit architectures we only use the first 4 bytes of the pointer
	slot. */

	ut_ad(dest_len - 8 > 1 || src_len < 1<<8);
	ut_ad(dest_len - 8 > 2 || src_len < 1<<16);
	ut_ad(dest_len - 8 > 3 || src_len < 1<<24);

	mach_write_to_n_little_endian(dest, dest_len - 8, src_len);

	memcpy(dest + dest_len - 8, &src, sizeof src);
}

/*******************************************************************//**
Read geometry data in the MySQL format.
@return pointer to geometry data */
static
const byte*
row_mysql_read_geometry(
/*====================*/
	ulint*		len,		/*!< out: data length */
	const byte*	ref,		/*!< in: geometry data in the
					MySQL format */
	ulint		col_len)	/*!< in: MySQL format length */
{
	byte*		data;
	ut_ad(col_len > 8);

	*len = mach_read_from_n_little_endian(ref, col_len - 8);

	memcpy(&data, ref + col_len - 8, sizeof data);

	return(data);
}

/**************************************************************//**
Pad a column with spaces. */
void
row_mysql_pad_col(
/*==============*/
	ulint	mbminlen,	/*!< in: minimum size of a character,
				in bytes */
	byte*	pad,		/*!< out: padded buffer */
	ulint	len)		/*!< in: number of bytes to pad */
{
	const byte*	pad_end;

	switch (UNIV_EXPECT(mbminlen, 1)) {
	default:
		ut_error;
	case 1:
		/* space=0x20 */
		memset(pad, 0x20, len);
		break;
	case 2:
		/* space=0x0020 */
		pad_end = pad + len;
		ut_a(!(len % 2));
		while (pad < pad_end) {
			*pad++ = 0x00;
			*pad++ = 0x20;
		};
		break;
	case 4:
		/* space=0x00000020 */
		pad_end = pad + len;
		ut_a(!(len % 4));
		while (pad < pad_end) {
			*pad++ = 0x00;
			*pad++ = 0x00;
			*pad++ = 0x00;
			*pad++ = 0x20;
		}
		break;
	}
}

/**************************************************************//**
Stores a non-SQL-NULL field given in the MySQL format in the InnoDB format.
The counterpart of this function is row_sel_field_store_in_mysql_format() in
row0sel.cc.
@return up to which byte we used buf in the conversion */
byte*
row_mysql_store_col_in_innobase_format(
/*===================================*/
	dfield_t*	dfield,		/*!< in/out: dfield where dtype
					information must be already set when
					this function is called! */
	byte*		buf,		/*!< in/out: buffer for a converted
					integer value; this must be at least
					col_len long then! NOTE that dfield
					may also get a pointer to 'buf',
					therefore do not discard this as long
					as dfield is used! */
	ibool		row_format_col,	/*!< TRUE if the mysql_data is from
					a MySQL row, FALSE if from a MySQL
					key value;
					in MySQL, a true VARCHAR storage
					format differs in a row and in a
					key value: in a key value the length
					is always stored in 2 bytes! */
	const byte*	mysql_data,	/*!< in: MySQL column value, not
					SQL NULL; NOTE that dfield may also
					get a pointer to mysql_data,
					therefore do not discard this as long
					as dfield is used! */
	ulint		col_len,	/*!< in: MySQL column length; NOTE that
					this is the storage length of the
					column in the MySQL format row, not
					necessarily the length of the actual
					payload data; if the column is a true
					VARCHAR then this is irrelevant */
	ulint		comp)		/*!< in: nonzero=compact format */
{
	const byte*	ptr	= mysql_data;
	const dtype_t*	dtype;
	ulint		type;
	ulint		lenlen;

	dtype = dfield_get_type(dfield);

	type = dtype->mtype;

	if (type == DATA_INT) {
		/* Store integer data in Innobase in a big-endian format,
		sign bit negated if the data is a signed integer. In MySQL,
		integers are stored in a little-endian format. */

		byte*	p = buf + col_len;

		for (;;) {
			p--;
			*p = *mysql_data;
			if (p == buf) {
				break;
			}
			mysql_data++;
		}

		if (!(dtype->prtype & DATA_UNSIGNED)) {

			*buf ^= 128;
		}

		ptr = buf;
		buf += col_len;
	} else if ((type == DATA_VARCHAR
		    || type == DATA_VARMYSQL
		    || type == DATA_BINARY)) {

		if (dtype_get_mysql_type(dtype) == DATA_MYSQL_TRUE_VARCHAR) {
			/* The length of the actual data is stored to 1 or 2
			bytes at the start of the field */

			if (row_format_col) {
				if (dtype->prtype & DATA_LONG_TRUE_VARCHAR) {
					lenlen = 2;
				} else {
					lenlen = 1;
				}
			} else {
				/* In a MySQL key value, lenlen is always 2 */
				lenlen = 2;
			}

			ptr = row_mysql_read_true_varchar(&col_len, mysql_data,
							  lenlen);
		} else {
			/* Remove trailing spaces from old style VARCHAR
			columns. */

			/* Handle Unicode strings differently. */
			ulint	mbminlen	= dtype_get_mbminlen(dtype);

			ptr = mysql_data;

			switch (mbminlen) {
			default:
				ut_error;
			case 4:
				/* space=0x00000020 */
				/* Trim "half-chars", just in case. */
				col_len &= ~3U;

				while (col_len >= 4
				       && ptr[col_len - 4] == 0x00
				       && ptr[col_len - 3] == 0x00
				       && ptr[col_len - 2] == 0x00
				       && ptr[col_len - 1] == 0x20) {
					col_len -= 4;
				}
				break;
			case 2:
				/* space=0x0020 */
				/* Trim "half-chars", just in case. */
				col_len &= ~1U;

				while (col_len >= 2 && ptr[col_len - 2] == 0x00
				       && ptr[col_len - 1] == 0x20) {
					col_len -= 2;
				}
				break;
			case 1:
				/* space=0x20 */
				while (col_len > 0
				       && ptr[col_len - 1] == 0x20) {
					col_len--;
				}
			}
		}
	} else if (comp && type == DATA_MYSQL
		   && dtype_get_mbminlen(dtype) == 1
		   && dtype_get_mbmaxlen(dtype) > 1) {
		/* In some cases we strip trailing spaces from UTF-8 and other
		multibyte charsets, from FIXED-length CHAR columns, to save
		space. UTF-8 would otherwise normally use 3 * the string length
		bytes to store an ASCII string! */

		/* We assume that this CHAR field is encoded in a
		variable-length character set where spaces have
		1:1 correspondence to 0x20 bytes, such as UTF-8.

		Consider a CHAR(n) field, a field of n characters.
		It will contain between n * mbminlen and n * mbmaxlen bytes.
		We will try to truncate it to n bytes by stripping
		space padding.	If the field contains single-byte
		characters only, it will be truncated to n characters.
		Consider a CHAR(5) field containing the string
		".a   " where "." denotes a 3-byte character represented
		by the bytes "$%&". After our stripping, the string will
		be stored as "$%&a " (5 bytes). The string
		".abc " will be stored as "$%&abc" (6 bytes).

		The space padding will be restored in row0sel.cc, function
		row_sel_field_store_in_mysql_format(). */

		ulint		n_chars;

		ut_a(!(dtype_get_len(dtype) % dtype_get_mbmaxlen(dtype)));

		n_chars = dtype_get_len(dtype) / dtype_get_mbmaxlen(dtype);

		/* Strip space padding. */
		while (col_len > n_chars && ptr[col_len - 1] == 0x20) {
			col_len--;
		}
	} else if (!row_format_col) {
		/* if mysql data is from a MySQL key value
		since the length is always stored in 2 bytes,
		we need do nothing here. */
	} else if (type == DATA_BLOB) {

		ptr = row_mysql_read_blob_ref(&col_len, mysql_data, col_len);
	} else if (DATA_GEOMETRY_MTYPE(type)) {
		ptr = row_mysql_read_geometry(&col_len, mysql_data, col_len);
	}

	dfield_set_data(dfield, ptr, col_len);

	return(buf);
}

/**************************************************************//**
Convert a row in the MySQL format to a row in the Innobase format. Note that
the function to convert a MySQL format key value to an InnoDB dtuple is
row_sel_convert_mysql_key_to_innobase() in row0sel.cc. */
static
void
row_mysql_convert_row_to_innobase(
/*==============================*/
	dtuple_t*	row,		/*!< in/out: Innobase row where the
					field type information is already
					copied there! */
	row_prebuilt_t*	prebuilt,	/*!< in: prebuilt struct where template
					must be of type ROW_MYSQL_WHOLE_ROW */
	const byte*	mysql_rec,	/*!< in: row in the MySQL format;
					NOTE: do not discard as long as
					row is used, as row may contain
					pointers to this record! */
	mem_heap_t**	blob_heap)	/*!< in: FIX_ME, remove this after
					server fixes its issue */
{
	const mysql_row_templ_t*templ;
	dfield_t*		dfield;
	ulint			i;
	ulint			n_col = 0;
	ulint			n_v_col = 0;

	ut_ad(prebuilt->template_type == ROW_MYSQL_WHOLE_ROW);
	ut_ad(prebuilt->mysql_template);

	for (i = 0; i < prebuilt->n_template; i++) {

		templ = prebuilt->mysql_template + i;

		if (templ->is_virtual) {
			ut_ad(n_v_col < dtuple_get_n_v_fields(row));
			dfield = dtuple_get_nth_v_field(row, n_v_col);
			n_v_col++;
		} else {
			dfield = dtuple_get_nth_field(row, n_col);
			n_col++;
		}

		if (templ->mysql_null_bit_mask != 0) {
			/* Column may be SQL NULL */

			if (mysql_rec[templ->mysql_null_byte_offset]
			    & (byte) (templ->mysql_null_bit_mask)) {

				/* It is SQL NULL */

				dfield_set_null(dfield);

				goto next_column;
			}
		}

		row_mysql_store_col_in_innobase_format(
			dfield,
			prebuilt->ins_upd_rec_buff + templ->mysql_col_offset,
			TRUE, /* MySQL row format data */
			mysql_rec + templ->mysql_col_offset,
			templ->mysql_col_len,
			dict_table_is_comp(prebuilt->table));

		/* server has issue regarding handling BLOB virtual fields,
		and we need to duplicate it with our own memory here */
		if (templ->is_virtual
		    && DATA_LARGE_MTYPE(dfield_get_type(dfield)->mtype)) {
			if (*blob_heap == NULL) {
				*blob_heap = mem_heap_create(dfield->len);
			}
			dfield_dup(dfield, *blob_heap);
		}
next_column:
		;
	}

	/* If there is a FTS doc id column and it is not user supplied (
	generated by server) then assign it a new doc id. */
	if (!prebuilt->table->fts) {
		return;
	}

	ut_a(prebuilt->table->fts->doc_col != ULINT_UNDEFINED);

	doc_id_t	doc_id;

	if (!DICT_TF2_FLAG_IS_SET(prebuilt->table, DICT_TF2_FTS_HAS_DOC_ID)) {
		if (prebuilt->table->fts->cache->first_doc_id
		    == FTS_NULL_DOC_ID) {
			fts_get_next_doc_id(prebuilt->table, &doc_id);
		}
		return;
	}

	dfield_t*	fts_doc_id = dtuple_get_nth_field(
		row, prebuilt->table->fts->doc_col);

	if (fts_get_next_doc_id(prebuilt->table, &doc_id) == DB_SUCCESS) {
		ut_a(doc_id != FTS_NULL_DOC_ID);
		ut_ad(sizeof(doc_id) == fts_doc_id->type.len);
		dfield_set_data(fts_doc_id, prebuilt->ins_upd_rec_buff
				+ prebuilt->mysql_row_len, 8);
		fts_write_doc_id(fts_doc_id->data, doc_id);
	} else {
		dfield_set_null(fts_doc_id);
	}
}

/****************************************************************//**
Handles user errors and lock waits detected by the database engine.
@return true if it was a lock wait and we should continue running the
query thread and in that case the thr is ALREADY in the running state. */
bool
row_mysql_handle_errors(
/*====================*/
	dberr_t*	new_err,/*!< out: possible new error encountered in
				lock wait, or if no new error, the value
				of trx->error_state at the entry of this
				function */
	trx_t*		trx,	/*!< in: transaction */
	que_thr_t*	thr,	/*!< in: query thread, or NULL */
	trx_savept_t*	savept)	/*!< in: savepoint, or NULL */
{
	dberr_t	err;

	DBUG_ENTER("row_mysql_handle_errors");
	DEBUG_SYNC_C("row_mysql_handle_errors");

handle_new_error:
	err = trx->error_state;

	ut_a(err != DB_SUCCESS);

	trx->error_state = DB_SUCCESS;

	DBUG_LOG("trx", "handle error: " << ut_strerr(err)
		 << ";id=" << ib::hex(trx->id) << ", " << trx);

	switch (err) {
	case DB_LOCK_WAIT_TIMEOUT:
		if (row_rollback_on_timeout) {
			goto rollback;
		}
		/* fall through */
	case DB_DUPLICATE_KEY:
	case DB_FOREIGN_DUPLICATE_KEY:
	case DB_TOO_BIG_RECORD:
	case DB_UNDO_RECORD_TOO_BIG:
	case DB_ROW_IS_REFERENCED:
	case DB_NO_REFERENCED_ROW:
	case DB_CANNOT_ADD_CONSTRAINT:
	case DB_TOO_MANY_CONCURRENT_TRXS:
	case DB_OUT_OF_FILE_SPACE:
	case DB_READ_ONLY:
	case DB_FTS_INVALID_DOCID:
	case DB_INTERRUPTED:
	case DB_CANT_CREATE_GEOMETRY_OBJECT:
	case DB_TABLE_NOT_FOUND:
	case DB_DECRYPTION_FAILED:
	case DB_COMPUTE_VALUE_FAILED:
	rollback_to_savept:
		DBUG_EXECUTE_IF("row_mysql_crash_if_error", {
					log_buffer_flush_to_disk();
					DBUG_SUICIDE(); });
		if (savept) {
			/* Roll back the latest, possibly incomplete insertion
			or update */

			trx->rollback(savept);
		}
		/* MySQL will roll back the latest SQL statement */
		break;
	case DB_LOCK_WAIT:
		lock_wait_suspend_thread(thr);

		if (trx->error_state != DB_SUCCESS) {
			que_thr_stop_for_mysql(thr);

			goto handle_new_error;
		}

		*new_err = err;

		DBUG_RETURN(true);

	case DB_DEADLOCK:
	case DB_LOCK_TABLE_FULL:
	rollback:
		/* Roll back the whole transaction; this resolution was added
		to version 3.23.43 */

		trx->rollback();
		break;

	case DB_MUST_GET_MORE_FILE_SPACE:
		ib::fatal() << "The database cannot continue operation because"
			" of lack of space. You must add a new data file"
			" to my.cnf and restart the database.";
		break;

	case DB_CORRUPTION:
	case DB_PAGE_CORRUPTED:
		ib::error() << "We detected index corruption in an InnoDB type"
			" table. You have to dump + drop + reimport the"
			" table or, in a case of widespread corruption,"
			" dump all InnoDB tables and recreate the whole"
			" tablespace. If the mysqld server crashes after"
			" the startup or when you dump the tables. "
			<< FORCE_RECOVERY_MSG;
		goto rollback_to_savept;
	case DB_FOREIGN_EXCEED_MAX_CASCADE:
		ib::error() << "Cannot delete/update rows with cascading"
			" foreign key constraints that exceed max depth of "
			<< FK_MAX_CASCADE_DEL << ". Please drop excessive"
			" foreign constraints and try again";
		goto rollback_to_savept;
	case DB_UNSUPPORTED:
		ib::error() << "Cannot delete/update rows with cascading"
			" foreign key constraints in timestamp-based temporal"
			" table. Please drop excessive"
			" foreign constraints and try again";
		goto rollback_to_savept;
	default:
		ib::fatal() << "Unknown error " << err;
	}

	if (trx->error_state != DB_SUCCESS) {
		*new_err = trx->error_state;
	} else {
		*new_err = err;
	}

	trx->error_state = DB_SUCCESS;

	DBUG_RETURN(false);
}

/********************************************************************//**
Create a prebuilt struct for a MySQL table handle.
@return own: a prebuilt struct */
row_prebuilt_t*
row_create_prebuilt(
/*================*/
	dict_table_t*	table,		/*!< in: Innobase table handle */
	ulint		mysql_row_len)	/*!< in: length in bytes of a row in
					the MySQL format */
{
	DBUG_ENTER("row_create_prebuilt");

	row_prebuilt_t*	prebuilt;
	mem_heap_t*	heap;
	dict_index_t*	clust_index;
	dict_index_t*	temp_index;
	dtuple_t*	ref;
	ulint		ref_len;
	uint		srch_key_len = 0;
	ulint		search_tuple_n_fields;

	search_tuple_n_fields = 2 * (dict_table_get_n_cols(table)
				     + dict_table_get_n_v_cols(table));

	clust_index = dict_table_get_first_index(table);

	/* Make sure that search_tuple is long enough for clustered index */
	ut_a(2 * unsigned(table->n_cols) >= unsigned(clust_index->n_fields)
	     - clust_index->table->n_dropped());

	ref_len = dict_index_get_n_unique(clust_index);


        /* Maximum size of the buffer needed for conversion of INTs from
	little endian format to big endian format in an index. An index
	can have maximum 16 columns (MAX_REF_PARTS) in it. Therfore
	Max size for PK: 16 * 8 bytes (BIGINT's size) = 128 bytes
	Max size Secondary index: 16 * 8 bytes + PK = 256 bytes. */
#define MAX_SRCH_KEY_VAL_BUFFER         2* (8 * MAX_REF_PARTS)

#define PREBUILT_HEAP_INITIAL_SIZE	\
	( \
	sizeof(*prebuilt) \
	/* allocd in this function */ \
	+ DTUPLE_EST_ALLOC(search_tuple_n_fields) \
	+ DTUPLE_EST_ALLOC(ref_len) \
	/* allocd in row_prebuild_sel_graph() */ \
	+ sizeof(sel_node_t) \
	+ sizeof(que_fork_t) \
	+ sizeof(que_thr_t) \
	/* allocd in row_get_prebuilt_update_vector() */ \
	+ sizeof(upd_node_t) \
	+ sizeof(upd_t) \
	+ sizeof(upd_field_t) \
	  * dict_table_get_n_cols(table) \
	+ sizeof(que_fork_t) \
	+ sizeof(que_thr_t) \
	/* allocd in row_get_prebuilt_insert_row() */ \
	+ sizeof(ins_node_t) \
	/* mysql_row_len could be huge and we are not \
	sure if this prebuilt instance is going to be \
	used in inserts */ \
	+ (mysql_row_len < 256 ? mysql_row_len : 0) \
	+ DTUPLE_EST_ALLOC(dict_table_get_n_cols(table) \
			   + dict_table_get_n_v_cols(table)) \
	+ sizeof(que_fork_t) \
	+ sizeof(que_thr_t) \
	+ sizeof(*prebuilt->pcur) \
	+ sizeof(*prebuilt->clust_pcur) \
	)

	/* Calculate size of key buffer used to store search key in
	InnoDB format. MySQL stores INTs in little endian format and
	InnoDB stores INTs in big endian format with the sign bit
	flipped. All other field types are stored/compared the same
	in MySQL and InnoDB, so we must create a buffer containing
	the INT key parts in InnoDB format.We need two such buffers
	since both start and end keys are used in records_in_range(). */

	for (temp_index = dict_table_get_first_index(table); temp_index;
	     temp_index = dict_table_get_next_index(temp_index)) {
		DBUG_EXECUTE_IF("innodb_srch_key_buffer_max_value",
			ut_a(temp_index->n_user_defined_cols
						== MAX_REF_PARTS););
		uint temp_len = 0;
		for (uint i = 0; i < temp_index->n_uniq; i++) {
			ulint type = temp_index->fields[i].col->mtype;
			if (type == DATA_INT) {
				temp_len +=
					temp_index->fields[i].fixed_len;
			}
		}
		srch_key_len = std::max(srch_key_len,temp_len);
	}

	ut_a(srch_key_len <= MAX_SRCH_KEY_VAL_BUFFER);

	DBUG_EXECUTE_IF("innodb_srch_key_buffer_max_value",
		ut_a(srch_key_len == MAX_SRCH_KEY_VAL_BUFFER););

	/* We allocate enough space for the objects that are likely to
	be created later in order to minimize the number of malloc()
	calls */
	heap = mem_heap_create(PREBUILT_HEAP_INITIAL_SIZE + 2 * srch_key_len);

	prebuilt = static_cast<row_prebuilt_t*>(
		mem_heap_zalloc(heap, sizeof(*prebuilt)));

	prebuilt->magic_n = ROW_PREBUILT_ALLOCATED;
	prebuilt->magic_n2 = ROW_PREBUILT_ALLOCATED;

	prebuilt->table = table;

	prebuilt->sql_stat_start = TRUE;
	prebuilt->heap = heap;

	prebuilt->srch_key_val_len = srch_key_len;
	if (prebuilt->srch_key_val_len) {
		prebuilt->srch_key_val1 = static_cast<byte*>(
			mem_heap_alloc(prebuilt->heap,
				       2 * prebuilt->srch_key_val_len));
		prebuilt->srch_key_val2 = prebuilt->srch_key_val1 +
						prebuilt->srch_key_val_len;
	} else {
		prebuilt->srch_key_val1 = NULL;
		prebuilt->srch_key_val2 = NULL;
	}

	prebuilt->pcur = static_cast<btr_pcur_t*>(
				mem_heap_zalloc(prebuilt->heap,
					       sizeof(btr_pcur_t)));
	prebuilt->clust_pcur = static_cast<btr_pcur_t*>(
					mem_heap_zalloc(prebuilt->heap,
						       sizeof(btr_pcur_t)));
	btr_pcur_reset(prebuilt->pcur);
	btr_pcur_reset(prebuilt->clust_pcur);

	prebuilt->select_lock_type = LOCK_NONE;
	prebuilt->stored_select_lock_type = LOCK_NONE_UNSET;

	prebuilt->search_tuple = dtuple_create(heap, search_tuple_n_fields);

	ref = dtuple_create(heap, ref_len);

	dict_index_copy_types(ref, clust_index, ref_len);

	prebuilt->clust_ref = ref;

	prebuilt->autoinc_error = DB_SUCCESS;
	prebuilt->autoinc_offset = 0;

	/* Default to 1, we will set the actual value later in
	ha_innobase::get_auto_increment(). */
	prebuilt->autoinc_increment = 1;

	prebuilt->autoinc_last_value = 0;

	/* During UPDATE and DELETE we need the doc id. */
	prebuilt->fts_doc_id = 0;

	prebuilt->mysql_row_len = mysql_row_len;

	prebuilt->fts_doc_id_in_read_set = 0;
	prebuilt->blob_heap = NULL;

	DBUG_RETURN(prebuilt);
}

/********************************************************************//**
Free a prebuilt struct for a MySQL table handle. */
void
row_prebuilt_free(
/*==============*/
	row_prebuilt_t*	prebuilt,	/*!< in, own: prebuilt struct */
	ibool		dict_locked)	/*!< in: TRUE=data dictionary locked */
{
	DBUG_ENTER("row_prebuilt_free");

	ut_a(prebuilt->magic_n == ROW_PREBUILT_ALLOCATED);
	ut_a(prebuilt->magic_n2 == ROW_PREBUILT_ALLOCATED);

	prebuilt->magic_n = ROW_PREBUILT_FREED;
	prebuilt->magic_n2 = ROW_PREBUILT_FREED;

	btr_pcur_reset(prebuilt->pcur);
	btr_pcur_reset(prebuilt->clust_pcur);

	ut_free(prebuilt->mysql_template);

	if (prebuilt->ins_graph) {
		que_graph_free_recursive(prebuilt->ins_graph);
	}

	if (prebuilt->sel_graph) {
		que_graph_free_recursive(prebuilt->sel_graph);
	}

	if (prebuilt->upd_graph) {
		que_graph_free_recursive(prebuilt->upd_graph);
	}

	if (prebuilt->blob_heap) {
		row_mysql_prebuilt_free_blob_heap(prebuilt);
	}

	if (prebuilt->old_vers_heap) {
		mem_heap_free(prebuilt->old_vers_heap);
	}

	if (prebuilt->fetch_cache[0] != NULL) {
		byte*	base = prebuilt->fetch_cache[0] - 4;
		byte*	ptr = base;

		for (ulint i = 0; i < MYSQL_FETCH_CACHE_SIZE; i++) {
			ulint	magic1 = mach_read_from_4(ptr);
			ut_a(magic1 == ROW_PREBUILT_FETCH_MAGIC_N);
			ptr += 4;

			byte*	row = ptr;
			ut_a(row == prebuilt->fetch_cache[i]);
			ptr += prebuilt->mysql_row_len;

			ulint	magic2 = mach_read_from_4(ptr);
			ut_a(magic2 == ROW_PREBUILT_FETCH_MAGIC_N);
			ptr += 4;
		}

		ut_free(base);
	}

	if (prebuilt->rtr_info) {
		rtr_clean_rtr_info(prebuilt->rtr_info, true);
	}
	if (prebuilt->table) {
		dict_table_close(prebuilt->table, dict_locked, FALSE);
	}

	mem_heap_free(prebuilt->heap);

	DBUG_VOID_RETURN;
}

/*********************************************************************//**
Updates the transaction pointers in query graphs stored in the prebuilt
struct. */
void
row_update_prebuilt_trx(
/*====================*/
	row_prebuilt_t*	prebuilt,	/*!< in/out: prebuilt struct
					in MySQL handle */
	trx_t*		trx)		/*!< in: transaction handle */
{
	ut_a(trx->magic_n == TRX_MAGIC_N);
	ut_a(prebuilt->magic_n == ROW_PREBUILT_ALLOCATED);
	ut_a(prebuilt->magic_n2 == ROW_PREBUILT_ALLOCATED);

	prebuilt->trx = trx;

	if (prebuilt->ins_graph) {
		prebuilt->ins_graph->trx = trx;
	}

	if (prebuilt->upd_graph) {
		prebuilt->upd_graph->trx = trx;
	}

	if (prebuilt->sel_graph) {
		prebuilt->sel_graph->trx = trx;
	}
}

/*********************************************************************//**
Gets pointer to a prebuilt dtuple used in insertions. If the insert graph
has not yet been built in the prebuilt struct, then this function first
builds it.
@return prebuilt dtuple; the column type information is also set in it */
static
dtuple_t*
row_get_prebuilt_insert_row(
/*========================*/
	row_prebuilt_t*	prebuilt)	/*!< in: prebuilt struct in MySQL
					handle */
{
	dict_table_t*		table	= prebuilt->table;

	ut_ad(prebuilt && table && prebuilt->trx);

	if (prebuilt->ins_node != 0) {

		/* Check if indexes have been dropped or added and we
		may need to rebuild the row insert template. */

		if (prebuilt->trx_id == table->def_trx_id
		    && prebuilt->ins_node->entry_list.size()
		    == UT_LIST_GET_LEN(table->indexes)) {

			return(prebuilt->ins_node->row);
		}

		ut_ad(prebuilt->trx_id < table->def_trx_id);

		que_graph_free_recursive(prebuilt->ins_graph);

		prebuilt->ins_graph = 0;
	}

	/* Create an insert node and query graph to the prebuilt struct */

	ins_node_t*		node;

	node = ins_node_create(INS_DIRECT, table, prebuilt->heap);

	prebuilt->ins_node = node;

	if (prebuilt->ins_upd_rec_buff == 0) {
		prebuilt->ins_upd_rec_buff = static_cast<byte*>(
			mem_heap_alloc(
				prebuilt->heap,
				DICT_TF2_FLAG_IS_SET(prebuilt->table,
						     DICT_TF2_FTS_HAS_DOC_ID)
				? prebuilt->mysql_row_len + 8/* FTS_DOC_ID */
				: prebuilt->mysql_row_len));
	}

	dtuple_t*	row;

	row = dtuple_create_with_vcol(
			prebuilt->heap, dict_table_get_n_cols(table),
			dict_table_get_n_v_cols(table));

	dict_table_copy_types(row, table);

	ins_node_set_new_row(node, row);

	prebuilt->ins_graph = static_cast<que_fork_t*>(
		que_node_get_parent(
			pars_complete_graph_for_exec(
				node,
				prebuilt->trx, prebuilt->heap, prebuilt)));

	prebuilt->ins_graph->state = QUE_FORK_ACTIVE;

	prebuilt->trx_id = table->def_trx_id;

	return(prebuilt->ins_node->row);
}

/*********************************************************************//**
Sets an AUTO_INC type lock on the table mentioned in prebuilt. The
AUTO_INC lock gives exclusive access to the auto-inc counter of the
table. The lock is reserved only for the duration of an SQL statement.
It is not compatible with another AUTO_INC or exclusive lock on the
table.
@return error code or DB_SUCCESS */
dberr_t
row_lock_table_autoinc_for_mysql(
/*=============================*/
	row_prebuilt_t*	prebuilt)	/*!< in: prebuilt struct in the MySQL
					table handle */
{
	trx_t*			trx	= prebuilt->trx;
	ins_node_t*		node	= prebuilt->ins_node;
	const dict_table_t*	table	= prebuilt->table;
	que_thr_t*		thr;
	dberr_t			err;
	ibool			was_lock_wait;

	/* If we already hold an AUTOINC lock on the table then do nothing.
	Note: We peek at the value of the current owner without acquiring
	the lock mutex. */
	if (trx == table->autoinc_trx) {

		return(DB_SUCCESS);
	}

	trx->op_info = "setting auto-inc lock";

	row_get_prebuilt_insert_row(prebuilt);
	node = prebuilt->ins_node;

	/* We use the insert query graph as the dummy graph needed
	in the lock module call */

	thr = que_fork_get_first_thr(prebuilt->ins_graph);

	thr->start_running();

run_again:
	thr->run_node = node;
	thr->prev_node = node;

	/* It may be that the current session has not yet started
	its transaction, or it has been committed: */

	trx_start_if_not_started_xa(trx, true);

	err = lock_table(0, prebuilt->table, LOCK_AUTO_INC, thr);

	trx->error_state = err;

	if (err != DB_SUCCESS) {
		que_thr_stop_for_mysql(thr);

		was_lock_wait = row_mysql_handle_errors(&err, trx, thr, NULL);

		if (was_lock_wait) {
			goto run_again;
		}

		trx->op_info = "";

		return(err);
	}

	thr->stop_no_error();

	trx->op_info = "";

	return(err);
}

/** Lock a table.
@param[in,out]	prebuilt	table handle
@return error code or DB_SUCCESS */
dberr_t
row_lock_table(row_prebuilt_t* prebuilt)
{
	trx_t*		trx		= prebuilt->trx;
	que_thr_t*	thr;
	dberr_t		err;
	ibool		was_lock_wait;

	trx->op_info = "setting table lock";

	if (prebuilt->sel_graph == NULL) {
		/* Build a dummy select query graph */
		row_prebuild_sel_graph(prebuilt);
	}

	/* We use the select query graph as the dummy graph needed
	in the lock module call */

	thr = que_fork_get_first_thr(prebuilt->sel_graph);

	thr->start_running();

run_again:
	thr->run_node = thr;
	thr->prev_node = thr->common.parent;

	/* It may be that the current session has not yet started
	its transaction, or it has been committed: */

	trx_start_if_not_started_xa(trx, false);

	err = lock_table(0, prebuilt->table,
			 static_cast<enum lock_mode>(
				 prebuilt->select_lock_type),
			 thr);

	trx->error_state = err;

	if (err != DB_SUCCESS) {
		que_thr_stop_for_mysql(thr);

		was_lock_wait = row_mysql_handle_errors(&err, trx, thr, NULL);

		if (was_lock_wait) {
			goto run_again;
		}

		trx->op_info = "";

		return(err);
	}

	thr->stop_no_error();

	trx->op_info = "";

	return(err);
}

/** Determine is tablespace encrypted but decryption failed, is table corrupted
or is tablespace .ibd file missing.
@param[in]	table		Table
@param[in]	trx		Transaction
@param[in]	push_warning	true if we should push warning to user
@retval	DB_DECRYPTION_FAILED	table is encrypted but decryption failed
@retval	DB_CORRUPTION		table is corrupted
@retval	DB_TABLESPACE_NOT_FOUND	tablespace .ibd file not found */
static
dberr_t
row_mysql_get_table_status(
	const dict_table_t*	table,
	trx_t*			trx,
	bool 			push_warning = true)
{
	dberr_t err;
	if (const fil_space_t* space = table->space) {
		if (space->crypt_data && space->crypt_data->is_encrypted()) {
			// maybe we cannot access the table due to failing
			// to decrypt
			if (push_warning) {
				ib_push_warning(trx, DB_DECRYPTION_FAILED,
					"Table %s in tablespace %lu encrypted."
					"However key management plugin or used key_id is not found or"
					" used encryption algorithm or method does not match.",
					table->name.m_name, table->space);
			}

			err = DB_DECRYPTION_FAILED;
		} else {
			if (push_warning) {
				ib_push_warning(trx, DB_CORRUPTION,
					"Table %s in tablespace %lu corrupted.",
					table->name.m_name, table->space);
			}

			err = DB_CORRUPTION;
		}
	} else {
		ib::error() << ".ibd file is missing for table "
			<< table->name;
		err = DB_TABLESPACE_NOT_FOUND;
	}

	return(err);
}

/** Does an insert for MySQL.
@param[in]	mysql_rec	row in the MySQL format
@param[in,out]	prebuilt	prebuilt struct in MySQL handle
@return error code or DB_SUCCESS */
dberr_t
row_insert_for_mysql(
	const byte*	mysql_rec,
	row_prebuilt_t*	prebuilt,
	ins_mode_t	ins_mode)
{
	trx_savept_t	savept;
	que_thr_t*	thr;
	dberr_t		err;
	ibool		was_lock_wait;
	trx_t*		trx		= prebuilt->trx;
	ins_node_t*	node		= prebuilt->ins_node;
	dict_table_t*	table		= prebuilt->table;

	/* FIX_ME: This blob heap is used to compensate an issue in server
	for virtual column blob handling */
	mem_heap_t*	blob_heap = NULL;

	ut_ad(trx);
	ut_a(prebuilt->magic_n == ROW_PREBUILT_ALLOCATED);
	ut_a(prebuilt->magic_n2 == ROW_PREBUILT_ALLOCATED);

	if (!prebuilt->table->space) {

		ib::error() << "The table " << prebuilt->table->name
			<< " doesn't have a corresponding tablespace, it was"
			" discarded.";

		return(DB_TABLESPACE_DELETED);

	} else if (!prebuilt->table->is_readable()) {
		return(row_mysql_get_table_status(prebuilt->table, trx, true));
	} else if (high_level_read_only) {
		return(DB_READ_ONLY);
	}

	DBUG_EXECUTE_IF("mark_table_corrupted", {
		/* Mark the table corrupted for the clustered index */
		dict_index_t*	index = dict_table_get_first_index(table);
		ut_ad(dict_index_is_clust(index));
		dict_set_corrupted(index, trx, "INSERT TABLE"); });

	if (dict_table_is_corrupted(table)) {

		ib::error() << "Table " << table->name << " is corrupt.";
		return(DB_TABLE_CORRUPT);
	}

	trx->op_info = "inserting";

	row_mysql_delay_if_needed();

	if (!table->no_rollback()) {
		trx_start_if_not_started_xa(trx, true);
	}

	row_get_prebuilt_insert_row(prebuilt);
	node = prebuilt->ins_node;

	row_mysql_convert_row_to_innobase(node->row, prebuilt, mysql_rec,
					  &blob_heap);

	if (ins_mode != ROW_INS_NORMAL) {
          node->vers_update_end(prebuilt, ins_mode == ROW_INS_HISTORICAL);
        }

	savept = trx_savept_take(trx);

	thr = que_fork_get_first_thr(prebuilt->ins_graph);

	if (prebuilt->sql_stat_start) {
		node->state = INS_NODE_SET_IX_LOCK;
		prebuilt->sql_stat_start = FALSE;
	} else {
		node->state = INS_NODE_ALLOC_ROW_ID;
	}

	thr->start_running();

run_again:
	thr->run_node = node;
	thr->prev_node = node;

	row_ins_step(thr);

	DEBUG_SYNC_C("ib_after_row_insert_step");

	err = trx->error_state;

	if (err != DB_SUCCESS) {
error_exit:
		que_thr_stop_for_mysql(thr);

		/* FIXME: What's this ? */
		thr->lock_state = QUE_THR_LOCK_ROW;

		was_lock_wait = row_mysql_handle_errors(
			&err, trx, thr, &savept);

		thr->lock_state = QUE_THR_LOCK_NOLOCK;

		if (was_lock_wait) {
			ut_ad(node->state == INS_NODE_INSERT_ENTRIES
			      || node->state == INS_NODE_ALLOC_ROW_ID);
			goto run_again;
		}

		trx->op_info = "";

		if (blob_heap != NULL) {
			mem_heap_free(blob_heap);
		}

		return(err);
	}

	if (dict_table_has_fts_index(table)) {
		doc_id_t	doc_id;

		/* Extract the doc id from the hidden FTS column */
		doc_id = fts_get_doc_id_from_row(table, node->row);

		if (doc_id <= 0) {
			ib::error() << "FTS_DOC_ID must be larger than 0 for table "
				    << table->name;
			err = DB_FTS_INVALID_DOCID;
			trx->error_state = DB_FTS_INVALID_DOCID;
			goto error_exit;
		}

		if (!DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_HAS_DOC_ID)) {
			doc_id_t	next_doc_id
				= table->fts->cache->next_doc_id;

			if (doc_id < next_doc_id) {
				ib::error() << "FTS_DOC_ID must be larger than "
					<< next_doc_id - 1 << " for table "
					<< table->name;

				err = DB_FTS_INVALID_DOCID;
				trx->error_state = DB_FTS_INVALID_DOCID;
				goto error_exit;
			}
		}

		if (table->skip_alter_undo) {
			if (trx->fts_trx == NULL) {
				trx->fts_trx = fts_trx_create(trx);
			}

			fts_trx_table_t ftt;
			ftt.table = table;
			ftt.fts_trx = trx->fts_trx;

			fts_add_doc_from_tuple(&ftt, doc_id, node->row);
		} else {
			/* Pass NULL for the columns affected, since an INSERT affects
			all FTS indexes. */
			fts_trx_add_op(trx, table, doc_id, FTS_INSERT, NULL);
		}
	}

	thr->stop_no_error();

	if (table->is_system_db) {
		srv_stats.n_system_rows_inserted.inc(size_t(trx->id));
	} else {
		srv_stats.n_rows_inserted.inc(size_t(trx->id));
	}

	/* Not protected by dict_sys.mutex for performance
	reasons, we would rather get garbage in stat_n_rows (which is
	just an estimate anyway) than protecting the following code
	with a latch. */
	dict_table_n_rows_inc(table);

	if (prebuilt->clust_index_was_generated) {
		/* set row id to prebuilt */
		memcpy(prebuilt->row_id, node->sys_buf, DATA_ROW_ID_LEN);
	}

	dict_stats_update_if_needed(table, *trx);
	trx->op_info = "";

	if (blob_heap != NULL) {
		mem_heap_free(blob_heap);
	}

	return(err);
}

/*********************************************************************//**
Builds a dummy query graph used in selects. */
void
row_prebuild_sel_graph(
/*===================*/
	row_prebuilt_t*	prebuilt)	/*!< in: prebuilt struct in MySQL
					handle */
{
	sel_node_t*	node;

	ut_ad(prebuilt && prebuilt->trx);

	if (prebuilt->sel_graph == NULL) {

		node = sel_node_create(prebuilt->heap);

		prebuilt->sel_graph = static_cast<que_fork_t*>(
			que_node_get_parent(
				pars_complete_graph_for_exec(
					static_cast<sel_node_t*>(node),
					prebuilt->trx, prebuilt->heap,
					prebuilt)));

		prebuilt->sel_graph->state = QUE_FORK_ACTIVE;
	}
}

/*********************************************************************//**
Creates an query graph node of 'update' type to be used in the MySQL
interface.
@return own: update node */
upd_node_t*
row_create_update_node_for_mysql(
/*=============================*/
	dict_table_t*	table,	/*!< in: table to update */
	mem_heap_t*	heap)	/*!< in: mem heap from which allocated */
{
	upd_node_t*	node;

	DBUG_ENTER("row_create_update_node_for_mysql");

	node = upd_node_create(heap);

	node->in_mysql_interface = true;
	node->is_delete = NO_DELETE;
	node->searched_update = FALSE;
	node->select = NULL;
	node->pcur = btr_pcur_create_for_mysql();

	DBUG_PRINT("info", ("node: %p, pcur: %p", node, node->pcur));

	node->table = table;

	node->update = upd_create(dict_table_get_n_cols(table)
				  + dict_table_get_n_v_cols(table), heap);

	node->update_n_fields = dict_table_get_n_cols(table);

	UT_LIST_INIT(node->columns, &sym_node_t::col_var_list);

	node->has_clust_rec_x_lock = TRUE;
	node->cmpl_info = 0;

	node->table_sym = NULL;
	node->col_assign_list = NULL;

	DBUG_RETURN(node);
}

/*********************************************************************//**
Gets pointer to a prebuilt update vector used in updates. If the update
graph has not yet been built in the prebuilt struct, then this function
first builds it.
@return prebuilt update vector */
upd_t*
row_get_prebuilt_update_vector(
/*===========================*/
	row_prebuilt_t*	prebuilt)	/*!< in: prebuilt struct in MySQL
					handle */
{
	if (prebuilt->upd_node == NULL) {

		/* Not called before for this handle: create an update node
		and query graph to the prebuilt struct */

		prebuilt->upd_node = row_create_update_node_for_mysql(
			prebuilt->table, prebuilt->heap);

		prebuilt->upd_graph = static_cast<que_fork_t*>(
			que_node_get_parent(
				pars_complete_graph_for_exec(
					prebuilt->upd_node,
					prebuilt->trx, prebuilt->heap,
					prebuilt)));

		prebuilt->upd_graph->state = QUE_FORK_ACTIVE;
	}

	return(prebuilt->upd_node->update);
}

/********************************************************************
Handle an update of a column that has an FTS index. */
static
void
row_fts_do_update(
/*==============*/
	trx_t*		trx,		/* in: transaction */
	dict_table_t*	table,		/* in: Table with FTS index */
	doc_id_t	old_doc_id,	/* in: old document id */
	doc_id_t	new_doc_id)	/* in: new document id */
{
	if(trx->fts_next_doc_id) {
		fts_trx_add_op(trx, table, old_doc_id, FTS_DELETE, NULL);
		if(new_doc_id != FTS_NULL_DOC_ID)
		fts_trx_add_op(trx, table, new_doc_id, FTS_INSERT, NULL);
	}
}

/************************************************************************
Handles FTS matters for an update or a delete.
NOTE: should not be called if the table does not have an FTS index. .*/
static
dberr_t
row_fts_update_or_delete(
/*=====================*/
	row_prebuilt_t*	prebuilt)	/* in: prebuilt struct in MySQL
					handle */
{
	trx_t*		trx = prebuilt->trx;
	dict_table_t*	table = prebuilt->table;
	upd_node_t*	node = prebuilt->upd_node;
	doc_id_t	old_doc_id = prebuilt->fts_doc_id;

	DBUG_ENTER("row_fts_update_or_delete");

	ut_a(dict_table_has_fts_index(prebuilt->table));

	/* Deletes are simple; get them out of the way first. */
	if (node->is_delete == PLAIN_DELETE) {
		/* A delete affects all FTS indexes, so we pass NULL */
		fts_trx_add_op(trx, table, old_doc_id, FTS_DELETE, NULL);
	} else {
		doc_id_t	new_doc_id;
		new_doc_id = fts_read_doc_id((byte*) &trx->fts_next_doc_id);

		if (new_doc_id == 0) {
			ib::error() << "InnoDB FTS: Doc ID cannot be 0";
			return(DB_FTS_INVALID_DOCID);
		}
		row_fts_do_update(trx, table, old_doc_id, new_doc_id);
	}

	DBUG_RETURN(DB_SUCCESS);
}

/*********************************************************************//**
Initialize the Doc ID system for FK table with FTS index */
static
void
init_fts_doc_id_for_ref(
/*====================*/
	dict_table_t*	table,		/*!< in: table */
	ulint*		depth)		/*!< in: recusive call depth */
{
	dict_foreign_t* foreign;

	table->fk_max_recusive_level = 0;

	(*depth)++;

	/* Limit on tables involved in cascading delete/update */
	if (*depth > FK_MAX_CASCADE_DEL) {
		return;
	}

	/* Loop through this table's referenced list and also
	recursively traverse each table's foreign table list */
	for (dict_foreign_set::iterator it = table->referenced_set.begin();
	     it != table->referenced_set.end();
	     ++it) {

		foreign = *it;

		ut_ad(foreign->foreign_table != NULL);

		if (foreign->foreign_table->fts != NULL) {
			fts_init_doc_id(foreign->foreign_table);
		}

		if (!foreign->foreign_table->referenced_set.empty()
		    && foreign->foreign_table != table) {
			init_fts_doc_id_for_ref(
				foreign->foreign_table, depth);
		}
	}
}

/** Does an update or delete of a row for MySQL.
@param[in,out]	prebuilt	prebuilt struct in MySQL handle
@return error code or DB_SUCCESS */
dberr_t
row_update_for_mysql(row_prebuilt_t* prebuilt)
{
	trx_savept_t	savept;
	dberr_t		err;
	que_thr_t*	thr;
	dict_index_t*	clust_index;
	upd_node_t*	node;
	dict_table_t*	table		= prebuilt->table;
	trx_t*		trx		= prebuilt->trx;
	ulint		fk_depth	= 0;
	bool		got_s_lock	= false;

	DBUG_ENTER("row_update_for_mysql");

	ut_ad(trx);
	ut_a(prebuilt->magic_n == ROW_PREBUILT_ALLOCATED);
	ut_a(prebuilt->magic_n2 == ROW_PREBUILT_ALLOCATED);
	ut_a(prebuilt->template_type == ROW_MYSQL_WHOLE_ROW);
	ut_ad(table->stat_initialized);

	if (!table->is_readable()) {
		return(row_mysql_get_table_status(table, trx, true));
	}

	if (high_level_read_only) {
		return(DB_READ_ONLY);
	}

	DEBUG_SYNC_C("innodb_row_update_for_mysql_begin");

	trx->op_info = "updating or deleting";

	row_mysql_delay_if_needed();

	init_fts_doc_id_for_ref(table, &fk_depth);

	if (!table->no_rollback()) {
		trx_start_if_not_started_xa(trx, true);
	}

	if (dict_table_is_referenced_by_foreign_key(table)) {
		/* Share lock the data dictionary to prevent any
		table dictionary (for foreign constraint) change.
		This is similar to row_ins_check_foreign_constraint
		check protect by the dictionary lock as well.
		In the future, this can be removed once the Foreign
		key MDL is implemented */
		row_mysql_freeze_data_dictionary(trx);
		init_fts_doc_id_for_ref(table, &fk_depth);
		row_mysql_unfreeze_data_dictionary(trx);
	}

	node = prebuilt->upd_node;
	const bool is_delete = node->is_delete == PLAIN_DELETE;
	ut_ad(node->table == table);

	clust_index = dict_table_get_first_index(table);

	btr_pcur_copy_stored_position(node->pcur,
				      prebuilt->pcur->btr_cur.index
				      == clust_index
				      ? prebuilt->pcur
				      : prebuilt->clust_pcur);

	ut_a(node->pcur->rel_pos == BTR_PCUR_ON);

	/* MySQL seems to call rnd_pos before updating each row it
	has cached: we can get the correct cursor position from
	prebuilt->pcur; NOTE that we cannot build the row reference
	from mysql_rec if the clustered index was automatically
	generated for the table: MySQL does not know anything about
	the row id used as the clustered index key */

	savept = trx_savept_take(trx);

	thr = que_fork_get_first_thr(prebuilt->upd_graph);

	node->state = UPD_NODE_UPDATE_CLUSTERED;

	ut_ad(!prebuilt->sql_stat_start);

	thr->start_running();

	ut_ad(!prebuilt->versioned_write || node->table->versioned());

	if (prebuilt->versioned_write) {
		if (node->is_delete == VERSIONED_DELETE) {
                  node->vers_make_delete(trx);
                } else if (node->update->affects_versioned()) {
                  node->vers_make_update(trx);
                }
	}

	for (;;) {
		thr->run_node = node;
		thr->prev_node = node;
		thr->fk_cascade_depth = 0;

		row_upd_step(thr);

		err = trx->error_state;

		if (err == DB_SUCCESS) {
			break;
		}

		que_thr_stop_for_mysql(thr);

		if (err == DB_RECORD_NOT_FOUND) {
			trx->error_state = DB_SUCCESS;
			goto error;
		}

		thr->lock_state= QUE_THR_LOCK_ROW;

		DEBUG_SYNC(trx->mysql_thd, "row_update_for_mysql_error");

		bool was_lock_wait = row_mysql_handle_errors(
			&err, trx, thr, &savept);
		thr->lock_state= QUE_THR_LOCK_NOLOCK;

		if (!was_lock_wait) {
			goto error;
		}
	}

	thr->stop_no_error();

	if (dict_table_has_fts_index(table)
	    && trx->fts_next_doc_id != UINT64_UNDEFINED) {
		err = row_fts_update_or_delete(prebuilt);
		if (UNIV_UNLIKELY(err != DB_SUCCESS)) {
			ut_ad("unexpected error" == 0);
			goto error;
		}
	}

	/* Completed cascading operations (if any) */
	if (got_s_lock) {
		row_mysql_unfreeze_data_dictionary(trx);
	}

	bool	update_statistics;
	ut_ad(is_delete == (node->is_delete == PLAIN_DELETE));

	if (is_delete) {
		/* Not protected by dict_sys.mutex for performance
		reasons, we would rather get garbage in stat_n_rows (which is
		just an estimate anyway) than protecting the following code
		with a latch. */
		dict_table_n_rows_dec(prebuilt->table);

		if (table->is_system_db) {
			srv_stats.n_system_rows_deleted.inc(size_t(trx->id));
		} else {
			srv_stats.n_rows_deleted.inc(size_t(trx->id));
		}

		update_statistics = !srv_stats_include_delete_marked;
	} else {
		if (table->is_system_db) {
			srv_stats.n_system_rows_updated.inc(size_t(trx->id));
		} else {
			srv_stats.n_rows_updated.inc(size_t(trx->id));
		}

		update_statistics
			= !(node->cmpl_info & UPD_NODE_NO_ORD_CHANGE);
	}

	if (update_statistics) {
		dict_stats_update_if_needed(prebuilt->table, *trx);
	} else {
		/* Always update the table modification counter. */
		prebuilt->table->stat_modified_counter++;
	}

	trx->op_info = "";

	DBUG_RETURN(err);

error:
	trx->op_info = "";
	if (got_s_lock) {
		row_mysql_unfreeze_data_dictionary(trx);
	}

	DBUG_RETURN(err);
}

/** This can only be used when the current transaction is at
READ COMMITTED or READ UNCOMMITTED isolation level.
Before calling this function row_search_for_mysql() must have
initialized prebuilt->new_rec_locks to store the information which new
record locks really were set. This function removes a newly set
clustered index record lock under prebuilt->pcur or
prebuilt->clust_pcur.  Thus, this implements a 'mini-rollback' that
releases the latest clustered index record lock we set.
@param[in,out]	prebuilt		prebuilt struct in MySQL handle
@param[in]	has_latches_on_recs	TRUE if called so that we have the
					latches on the records under pcur
					and clust_pcur, and we do not need
					to reposition the cursors. */
void
row_unlock_for_mysql(
	row_prebuilt_t*	prebuilt,
	ibool		has_latches_on_recs)
{
	btr_pcur_t*	pcur		= prebuilt->pcur;
	btr_pcur_t*	clust_pcur	= prebuilt->clust_pcur;
	trx_t*		trx		= prebuilt->trx;

	ut_ad(prebuilt != NULL);
	ut_ad(trx != NULL);
	ut_ad(trx->isolation_level <= TRX_ISO_READ_COMMITTED);

	if (dict_index_is_spatial(prebuilt->index)) {
		return;
	}

	trx->op_info = "unlock_row";

	if (prebuilt->new_rec_locks >= 1) {

		const rec_t*	rec;
		dict_index_t*	index;
		trx_id_t	rec_trx_id;
		mtr_t		mtr;

		mtr_start(&mtr);

		/* Restore the cursor position and find the record */

		if (!has_latches_on_recs) {
			btr_pcur_restore_position(BTR_SEARCH_LEAF, pcur, &mtr);
		}

		rec = btr_pcur_get_rec(pcur);
		index = btr_pcur_get_btr_cur(pcur)->index;

		if (prebuilt->new_rec_locks >= 2) {
			/* Restore the cursor position and find the record
			in the clustered index. */

			if (!has_latches_on_recs) {
				btr_pcur_restore_position(BTR_SEARCH_LEAF,
							  clust_pcur, &mtr);
			}

			rec = btr_pcur_get_rec(clust_pcur);
			index = btr_pcur_get_btr_cur(clust_pcur)->index;
		}

		if (!dict_index_is_clust(index)) {
			/* This is not a clustered index record.  We
			do not know how to unlock the record. */
			goto no_unlock;
		}

		/* If the record has been modified by this
		transaction, do not unlock it. */

		if (index->trx_id_offset) {
			rec_trx_id = trx_read_trx_id(rec
						     + index->trx_id_offset);
		} else {
			mem_heap_t*	heap			= NULL;
			rec_offs offsets_[REC_OFFS_NORMAL_SIZE];
			rec_offs* offsets				= offsets_;

			rec_offs_init(offsets_);
			offsets = rec_get_offsets(rec, index, offsets,
						  index->n_core_fields,
						  ULINT_UNDEFINED, &heap);

			rec_trx_id = row_get_rec_trx_id(rec, index, offsets);

			if (UNIV_LIKELY_NULL(heap)) {
				mem_heap_free(heap);
			}
		}

		if (rec_trx_id != trx->id) {
			/* We did not update the record: unlock it */

			rec = btr_pcur_get_rec(pcur);

			lock_rec_unlock(
				trx,
				btr_pcur_get_block(pcur),
				rec,
				static_cast<enum lock_mode>(
					prebuilt->select_lock_type));

			if (prebuilt->new_rec_locks >= 2) {
				rec = btr_pcur_get_rec(clust_pcur);

				lock_rec_unlock(
					trx,
					btr_pcur_get_block(clust_pcur),
					rec,
					static_cast<enum lock_mode>(
						prebuilt->select_lock_type));
			}
		}
no_unlock:
		mtr_commit(&mtr);
	}

	trx->op_info = "";
}

/*********************************************************************//**
Locks the data dictionary in shared mode from modifications, for performing
foreign key check, rollback, or other operation invisible to MySQL. */
void
row_mysql_freeze_data_dictionary_func(
/*==================================*/
	trx_t*		trx,	/*!< in/out: transaction */
	const char*	file,	/*!< in: file name */
	unsigned	line)	/*!< in: line number */
{
	ut_a(trx->dict_operation_lock_mode == 0);

	rw_lock_s_lock_inline(&dict_sys.latch, 0, file, line);

	trx->dict_operation_lock_mode = RW_S_LATCH;
}

/*********************************************************************//**
Unlocks the data dictionary shared lock. */
void
row_mysql_unfreeze_data_dictionary(
/*===============================*/
	trx_t*	trx)	/*!< in/out: transaction */
{
	ut_ad(lock_trx_has_sys_table_locks(trx) == NULL);

	ut_a(trx->dict_operation_lock_mode == RW_S_LATCH);

	rw_lock_s_unlock(&dict_sys.latch);

	trx->dict_operation_lock_mode = 0;
}

/** Write query start time as SQL field data to a buffer. Needed by InnoDB.
@param	thd	Thread object
@param	buf	Buffer to hold start time data */
void thd_get_query_start_data(THD *thd, char *buf);

/** Insert history row when evaluating foreign key referential action.

1. Create new dtuple_t 'row' from node->historical_row;
2. Update its row_end to current timestamp;
3. Insert it to a table;
4. Update table statistics.

This is used in UPDATE CASCADE/SET NULL of a system versioned referenced table.

node->historical_row: dtuple_t containing pointers of row changed by refertial
action.

@param[in]	thr	current query thread
@param[in]	node	a node which just updated a row in a foreign table
@return DB_SUCCESS or some error */
static dberr_t row_update_vers_insert(que_thr_t* thr, upd_node_t* node)
{
	trx_t* trx = thr_get_trx(thr);
	dfield_t* row_end;
	char row_end_data[8];
	dict_table_t* table = node->table;
	const unsigned zip_size = table->space->zip_size();
	ut_ad(table->versioned());

	dtuple_t*       row;
	const ulint     n_cols        = dict_table_get_n_cols(table);
	const ulint     n_v_cols      = dict_table_get_n_v_cols(table);

	ut_ad(n_cols == dtuple_get_n_fields(node->historical_row));
	ut_ad(n_v_cols == dtuple_get_n_v_fields(node->historical_row));

	row = dtuple_create_with_vcol(node->historical_heap, n_cols, n_v_cols);

	dict_table_copy_types(row, table);

	ins_node_t* insert_node =
		ins_node_create(INS_DIRECT, table, node->historical_heap);

	if (!insert_node) {
		trx->error_state = DB_OUT_OF_MEMORY;
		goto exit;
	}

	insert_node->common.parent = thr;
	ins_node_set_new_row(insert_node, row);

	ut_ad(n_cols > DATA_N_SYS_COLS);
	// Exclude DB_ROW_ID, DB_TRX_ID, DB_ROLL_PTR
	for (ulint i = 0; i < n_cols - DATA_N_SYS_COLS; i++) {
		dfield_t *src= dtuple_get_nth_field(node->historical_row, i);
		dfield_t *dst= dtuple_get_nth_field(row, i);
		dfield_copy(dst, src);
		if (dfield_is_ext(src)) {
			byte *field_data
				= static_cast<byte*>(dfield_get_data(src));
			ulint ext_len;
			ulint field_len = dfield_get_len(src);

			ut_a(field_len >= BTR_EXTERN_FIELD_REF_SIZE);

			ut_a(memcmp(field_data + field_len
				     - BTR_EXTERN_FIELD_REF_SIZE,
				     field_ref_zero,
				     BTR_EXTERN_FIELD_REF_SIZE));

			byte *data = btr_copy_externally_stored_field(
				&ext_len, field_data, zip_size, field_len,
				node->historical_heap);
			dfield_set_data(dst, data, ext_len);
		}
	}

	for (ulint i = 0; i < n_v_cols; i++) {
		dfield_t *dst= dtuple_get_nth_v_field(row, i);
		dfield_t *src= dtuple_get_nth_v_field(node->historical_row, i);
		dfield_copy(dst, src);
	}

	node->historical_row = NULL;

	row_end = dtuple_get_nth_field(row, table->vers_end);
	if (dict_table_get_nth_col(table, table->vers_end)->vers_native()) {
		mach_write_to_8(row_end_data, trx->id);
		dfield_set_data(row_end, row_end_data, 8);
	} else {
		thd_get_query_start_data(trx->mysql_thd, row_end_data);
		dfield_set_data(row_end, row_end_data, 7);
	}

	for (;;) {
		thr->run_node = insert_node;
		thr->prev_node = insert_node;

		row_ins_step(thr);

		switch (trx->error_state) {
		case DB_LOCK_WAIT:
			que_thr_stop_for_mysql(thr);
			lock_wait_suspend_thread(thr);

			if (trx->error_state == DB_SUCCESS) {
				continue;
			}

			/* fall through */
		default:
			/* Other errors are handled for the parent node. */
			thr->fk_cascade_depth = 0;
			goto exit;

		case DB_SUCCESS:
			srv_stats.n_rows_inserted.inc(
				static_cast<size_t>(trx->id));
			dict_stats_update_if_needed(table, *trx);
			goto exit;
		}
	}
exit:
	que_graph_free_recursive(insert_node);
	mem_heap_free(node->historical_heap);
	node->historical_heap = NULL;
	return trx->error_state;
}

/**********************************************************************//**
Does a cascaded delete or set null in a foreign key operation.
@return error code or DB_SUCCESS */
dberr_t
row_update_cascade_for_mysql(
/*=========================*/
        que_thr_t*      thr,    /*!< in: query thread */
        upd_node_t*     node,   /*!< in: update node used in the cascade
                                or set null operation */
        dict_table_t*   table)  /*!< in: table where we do the operation */
{
        /* Increment fk_cascade_depth to record the recursive call depth on
        a single update/delete that affects multiple tables chained
        together with foreign key relations. */

        if (++thr->fk_cascade_depth > FK_MAX_CASCADE_DEL) {
                return(DB_FOREIGN_EXCEED_MAX_CASCADE);
        }

	const trx_t* trx = thr_get_trx(thr);

	if (table->versioned()) {
		if (node->is_delete == PLAIN_DELETE) {
                  node->vers_make_delete(trx);
                } else if (node->update->affects_versioned()) {
			dberr_t err = row_update_vers_insert(thr, node);
			if (err != DB_SUCCESS) {
				return err;
			}
                        node->vers_make_update(trx);
                }
	}

	for (;;) {
		thr->run_node = node;
		thr->prev_node = node;

		DEBUG_SYNC_C("foreign_constraint_update_cascade");
		{
			TABLE *mysql_table = thr->prebuilt->m_mysql_table;
			thr->prebuilt->m_mysql_table = NULL;
			row_upd_step(thr);
			thr->prebuilt->m_mysql_table = mysql_table;
		}

		switch (trx->error_state) {
		case DB_LOCK_WAIT:
			que_thr_stop_for_mysql(thr);
			lock_wait_suspend_thread(thr);

			if (trx->error_state == DB_SUCCESS) {
				continue;
			}

			/* fall through */
		default:
			/* Other errors are handled for the parent node. */
			thr->fk_cascade_depth = 0;
			return trx->error_state;

		case DB_SUCCESS:
			thr->fk_cascade_depth = 0;
			bool stats;

			if (node->is_delete == PLAIN_DELETE) {
				/* Not protected by dict_sys.mutex for
				performance reasons, we would rather
				get garbage in stat_n_rows (which is
				just an estimate anyway) than
				protecting the following code with a
				latch. */
				dict_table_n_rows_dec(node->table);

				stats = !srv_stats_include_delete_marked;
				srv_stats.n_rows_deleted.inc(size_t(trx->id));
			} else {
				stats = !(node->cmpl_info
					  & UPD_NODE_NO_ORD_CHANGE);
				srv_stats.n_rows_updated.inc(size_t(trx->id));
			}

			if (stats) {
				dict_stats_update_if_needed(node->table, *trx);
			} else {
				/* Always update the table
				modification counter. */
				node->table->stat_modified_counter++;
			}

			return(DB_SUCCESS);
		}
	}
}

/*********************************************************************//**
Locks the data dictionary exclusively for performing a table create or other
data dictionary modification operation. */
void
row_mysql_lock_data_dictionary_func(
/*================================*/
	trx_t*		trx,	/*!< in/out: transaction */
	const char*	file,	/*!< in: file name */
	unsigned	line)	/*!< in: line number */
{
	ut_a(trx->dict_operation_lock_mode == 0
	     || trx->dict_operation_lock_mode == RW_X_LATCH);
	dict_sys.lock(file, line);
	trx->dict_operation_lock_mode = RW_X_LATCH;
}

/*********************************************************************//**
Unlocks the data dictionary exclusive lock. */
void
row_mysql_unlock_data_dictionary(
/*=============================*/
	trx_t*	trx)	/*!< in/out: transaction */
{
	ut_ad(lock_trx_has_sys_table_locks(trx) == NULL);
	ut_a(trx->dict_operation_lock_mode == RW_X_LATCH);
	trx->dict_operation_lock_mode = 0;
	dict_sys.unlock();
}

/*********************************************************************//**
Creates a table for MySQL. On failure the transaction will be rolled back
and the 'table' object will be freed.
@return error code or DB_SUCCESS */
dberr_t
row_create_table_for_mysql(
/*=======================*/
	dict_table_t*	table,	/*!< in, own: table definition
				(will be freed, or on DB_SUCCESS
				added to the data dictionary cache) */
	trx_t*		trx,	/*!< in/out: transaction */
	fil_encryption_t mode,	/*!< in: encryption mode */
	uint32_t	key_id)	/*!< in: encryption key_id */
{
	tab_node_t*	node;
	mem_heap_t*	heap;
	que_thr_t*	thr;
	dberr_t		err;

	ut_d(dict_sys.assert_locked());
	ut_ad(trx->dict_operation_lock_mode == RW_X_LATCH);

	DBUG_EXECUTE_IF(
		"ib_create_table_fail_at_start_of_row_create_table_for_mysql",
		dict_mem_table_free(table);
		trx->op_info = "";
		return DB_ERROR;
	);

	trx->op_info = "creating table";

	trx_start_if_not_started_xa(trx, true);

	heap = mem_heap_create(512);

	switch (trx_get_dict_operation(trx)) {
	case TRX_DICT_OP_NONE:
		trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);
	case TRX_DICT_OP_TABLE:
		break;
	case TRX_DICT_OP_INDEX:
		/* If the transaction was previously flagged as
		TRX_DICT_OP_INDEX, we should be creating auxiliary
		tables for full-text indexes. */
		ut_ad(strstr(table->name.m_name, "/FTS_") != NULL);
	}

	node = tab_create_graph_create(table, heap, mode, key_id);

	thr = pars_complete_graph_for_exec(node, trx, heap, NULL);

	ut_a(thr == que_fork_start_command(
			static_cast<que_fork_t*>(que_node_get_parent(thr))));

	que_run_threads(thr);

	err = trx->error_state;

	/* Update SYS_TABLESPACES and SYS_DATAFILES if a new file-per-table
	tablespace was created. */
	if (err == DB_SUCCESS && dict_table_is_file_per_table(table)) {
		err = dict_replace_tablespace_in_dictionary(
			table->space_id, table->name.m_name,
			table->space->flags,
			table->space->chain.start->name, trx);

		if (err != DB_SUCCESS) {

			/* We must delete the link file. */
			RemoteDatafile::delete_link_file(table->name.m_name);
		}
	}

	switch (err) {
	case DB_SUCCESS:
		break;
	case DB_OUT_OF_FILE_SPACE:
		trx->error_state = DB_SUCCESS;
		trx->rollback();

		ib::warn() << "Cannot create table "
			<< table->name
			<< " because tablespace full";

		if (dict_table_open_on_name(table->name.m_name, TRUE, FALSE,
					    DICT_ERR_IGNORE_NONE)) {

			dict_table_close_and_drop(trx, table);
		} else {
			dict_mem_table_free(table);
		}

		break;

	case DB_UNSUPPORTED:
	case DB_TOO_MANY_CONCURRENT_TRXS:
		/* We already have .ibd file here. it should be deleted. */

		if (dict_table_is_file_per_table(table)
		    && fil_delete_tablespace(table->space_id) != DB_SUCCESS) {
			ib::error() << "Cannot delete the file of table "
				<< table->name;
		}
		/* fall through */

	case DB_DUPLICATE_KEY:
	case DB_TABLESPACE_EXISTS:
	default:
		trx->error_state = DB_SUCCESS;
		trx->rollback();
		dict_mem_table_free(table);
		break;
	}

	que_graph_free((que_t*) que_node_get_parent(thr));

	trx->op_info = "";

	return(err);
}

/*********************************************************************//**
Create an index when creating a table.
On failure, the caller must drop the table!
@return error number or DB_SUCCESS */
dberr_t
row_create_index_for_mysql(
/*=======================*/
	dict_index_t*	index,		/*!< in, own: index definition
					(will be freed) */
	trx_t*		trx,		/*!< in: transaction handle */
	const ulint*	field_lengths)	/*!< in: if not NULL, must contain
					dict_index_get_n_fields(index)
					actual field lengths for the
					index columns, which are
					then checked for not being too
					large. */
{
	ind_node_t*	node;
	mem_heap_t*	heap;
	que_thr_t*	thr;
	dberr_t		err;
	ulint		i;
	ulint		len;
	dict_table_t*	table = index->table;

	ut_d(dict_sys.assert_locked());

	for (i = 0; i < index->n_def; i++) {
		/* Check that prefix_len and actual length
		< DICT_MAX_INDEX_COL_LEN */

		len = dict_index_get_nth_field(index, i)->prefix_len;

		if (field_lengths && field_lengths[i]) {
			len = ut_max(len, field_lengths[i]);
		}

		DBUG_EXECUTE_IF(
			"ib_create_table_fail_at_create_index",
			len = DICT_MAX_FIELD_LEN_BY_FORMAT(table) + 1;
		);

		/* Column or prefix length exceeds maximum column length */
		if (len > (ulint) DICT_MAX_FIELD_LEN_BY_FORMAT(table)) {
			dict_mem_index_free(index);
			return DB_TOO_BIG_INDEX_COL;
		}
	}

	trx->op_info = "creating index";

	/* For temp-table we avoid insertion into SYSTEM TABLES to
	maintain performance and so we have separate path that directly
	just updates dictonary cache. */
	if (!table->is_temporary()) {
		trx_start_if_not_started_xa(trx, true);
		trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);
		/* Note that the space id where we store the index is
		inherited from the table in dict_build_index_def_step()
		in dict0crea.cc. */

		heap = mem_heap_create(512);
		node = ind_create_graph_create(index, table->name.m_name,
					       heap);

		thr = pars_complete_graph_for_exec(node, trx, heap, NULL);

		ut_a(thr == que_fork_start_command(
				static_cast<que_fork_t*>(
					que_node_get_parent(thr))));

		que_run_threads(thr);

		err = trx->error_state;

		index = node->index;

		ut_ad(!index == (err != DB_SUCCESS));

		que_graph_free((que_t*) que_node_get_parent(thr));

		if (index && (index->type & DICT_FTS)) {
			err = fts_create_index_tables(trx, index, table->id);
		}
	} else {
		dict_build_index_def(table, index, trx);

		err = dict_index_add_to_cache(index, FIL_NULL);
		ut_ad((index == NULL) == (err != DB_SUCCESS));
		if (UNIV_LIKELY(err == DB_SUCCESS)) {
			ut_ad(!index->is_instant());
			index->n_core_null_bytes = static_cast<uint8_t>(
				UT_BITS_IN_BYTES(unsigned(index->n_nullable)));

			err = dict_create_index_tree_in_mem(index, trx);
#ifdef BTR_CUR_HASH_ADAPT
			ut_ad(!index->search_info->ref_count);
#endif /* BTR_CUR_HASH_ADAPT */

			if (err != DB_SUCCESS) {
				dict_index_remove_from_cache(table, index);
			}
		}
	}

	trx->op_info = "";

	return(err);
}

/*********************************************************************//**
Drops a table for MySQL as a background operation. MySQL relies on Unix
in ALTER TABLE to the fact that the table handler does not remove the
table before all handles to it has been removed. Furhermore, the MySQL's
call to drop table must be non-blocking. Therefore we do the drop table
as a background operation, which is taken care of by the master thread
in srv0srv.cc.
@return error code or DB_SUCCESS */
static
dberr_t
row_drop_table_for_mysql_in_background(
/*===================================*/
	const char*	name)	/*!< in: table name */
{
	dberr_t	error;
	trx_t*	trx;

	trx = trx_create();

	/* If the original transaction was dropping a table referenced by
	foreign keys, we must set the following to be able to drop the
	table: */

	trx->check_foreigns = false;

	/* Try to drop the table in InnoDB */

	error = row_drop_table_for_mysql(name, trx, SQLCOM_TRUNCATE);

	trx_commit_for_mysql(trx);

	trx->free();

	return(error);
}

/*********************************************************************//**
The master thread in srv0srv.cc calls this regularly to drop tables which
we must drop in background after queries to them have ended. Such lazy
dropping of tables is needed in ALTER TABLE on Unix.
@return how many tables dropped + remaining tables in list */
ulint
row_drop_tables_for_mysql_in_background(void)
/*=========================================*/
{
	row_mysql_drop_t*	drop;
	dict_table_t*		table;
	ulint			n_tables;
	ulint			n_tables_dropped = 0;
loop:
	mutex_enter(&row_drop_list_mutex);

	ut_a(row_mysql_drop_list_inited);
next:
	drop = UT_LIST_GET_FIRST(row_mysql_drop_list);

	n_tables = UT_LIST_GET_LEN(row_mysql_drop_list);

	mutex_exit(&row_drop_list_mutex);

	if (drop == NULL) {
		/* All tables dropped */

		return(n_tables + n_tables_dropped);
	}

	/* On fast shutdown, just empty the list without dropping tables. */
	table = srv_shutdown_state == SRV_SHUTDOWN_NONE || !srv_fast_shutdown
		? dict_table_open_on_id(drop->table_id, FALSE,
					DICT_TABLE_OP_OPEN_ONLY_IF_CACHED)
		: NULL;

	if (!table) {
		n_tables_dropped++;
		mutex_enter(&row_drop_list_mutex);
		UT_LIST_REMOVE(row_mysql_drop_list, drop);
		MONITOR_DEC(MONITOR_BACKGROUND_DROP_TABLE);
		ut_free(drop);
		goto next;
	}

	ut_a(!table->can_be_evicted);

	bool skip = false;

	if (!table->to_be_dropped) {
skip:
		dict_table_close(table, FALSE, FALSE);

		mutex_enter(&row_drop_list_mutex);
		UT_LIST_REMOVE(row_mysql_drop_list, drop);
		if (!skip) {
			UT_LIST_ADD_LAST(row_mysql_drop_list, drop);
		} else {
			ut_free(drop);
		}
		goto next;
	}

	if (!srv_fast_shutdown && !trx_sys.any_active_transactions()) {
		lock_mutex_enter();
		skip = UT_LIST_GET_LEN(table->locks) != 0;
		lock_mutex_exit();
		if (skip) {
			/* We cannot drop tables that are locked by XA
			PREPARE transactions. */
			goto skip;
		}
	}

	char* name = mem_strdup(table->name.m_name);

	dict_table_close(table, FALSE, FALSE);

	dberr_t err = row_drop_table_for_mysql_in_background(name);

	ut_free(name);

	if (err != DB_SUCCESS) {
		/* If the DROP fails for some table, we return, and let the
		main thread retry later */
		return(n_tables + n_tables_dropped);
	}

	goto loop;
}

/*********************************************************************//**
Get the background drop list length. NOTE: the caller must own the
drop list mutex!
@return how many tables in list */
ulint
row_get_background_drop_list_len_low(void)
/*======================================*/
{
	ulint	len;

	mutex_enter(&row_drop_list_mutex);

	ut_a(row_mysql_drop_list_inited);

	len = UT_LIST_GET_LEN(row_mysql_drop_list);

	mutex_exit(&row_drop_list_mutex);

	return(len);
}

/** Drop garbage tables during recovery. */
void
row_mysql_drop_garbage_tables()
{
	mem_heap_t*	heap = mem_heap_create(FN_REFLEN);
	btr_pcur_t	pcur;
	mtr_t		mtr;
	trx_t*		trx = trx_create();
	trx->op_info = "dropping garbage tables";
	row_mysql_lock_data_dictionary(trx);

	mtr.start();
	btr_pcur_open_at_index_side(
		true, dict_table_get_first_index(dict_sys.sys_tables),
		BTR_SEARCH_LEAF, &pcur, true, 0, &mtr);

	for (;;) {
		const rec_t*	rec;
		const byte*	field;
		ulint		len;
		const char*	table_name;

		btr_pcur_move_to_next_user_rec(&pcur, &mtr);

		if (!btr_pcur_is_on_user_rec(&pcur)) {
			break;
		}

		rec = btr_pcur_get_rec(&pcur);
		if (rec_get_deleted_flag(rec, 0)) {
			continue;
		}

		field = rec_get_nth_field_old(rec, 0/*NAME*/, &len);
		if (len == UNIV_SQL_NULL || len == 0) {
			/* Corrupted SYS_TABLES.NAME */
			continue;
		}

		table_name = mem_heap_strdupl(
			heap,
			reinterpret_cast<const char*>(field), len);
		if (strstr(table_name, "/" TEMP_FILE_PREFIX "-") &&
                    !strstr(table_name, "/" TEMP_FILE_PREFIX "-backup-") &&
                    !strstr(table_name, "/" TEMP_FILE_PREFIX "-exchange-"))
                {
			btr_pcur_store_position(&pcur, &mtr);
			btr_pcur_commit_specify_mtr(&pcur, &mtr);

			if (dict_load_table(table_name,
					    DICT_ERR_IGNORE_DROP)) {
				row_drop_table_for_mysql(table_name, trx,
							 SQLCOM_DROP_TABLE);
				trx_commit_for_mysql(trx);
			}

			mtr.start();
			btr_pcur_restore_position(BTR_SEARCH_LEAF,
						  &pcur, &mtr);
		}

		mem_heap_empty(heap);
	}

	btr_pcur_close(&pcur);
	mtr.commit();
	row_mysql_unlock_data_dictionary(trx);
	trx->free();
	mem_heap_free(heap);
}

/*********************************************************************//**
If a table is not yet in the drop list, adds the table to the list of tables
which the master thread drops in background. We need this on Unix because in
ALTER TABLE MySQL may call drop table even if the table has running queries on
it. Also, if there are running foreign key checks on the table, we drop the
table lazily.
@return	whether background DROP TABLE was scheduled for the first time */
static
bool
row_add_table_to_background_drop_list(table_id_t table_id)
{
	row_mysql_drop_t*	drop;
	bool			added = true;

	mutex_enter(&row_drop_list_mutex);

	ut_a(row_mysql_drop_list_inited);

	/* Look if the table already is in the drop list */
	for (drop = UT_LIST_GET_FIRST(row_mysql_drop_list);
	     drop != NULL;
	     drop = UT_LIST_GET_NEXT(row_mysql_drop_list, drop)) {

		if (drop->table_id == table_id) {
			added = false;
			goto func_exit;
		}
	}

	drop = static_cast<row_mysql_drop_t*>(ut_malloc_nokey(sizeof *drop));
	drop->table_id = table_id;

	UT_LIST_ADD_LAST(row_mysql_drop_list, drop);

	MONITOR_INC(MONITOR_BACKGROUND_DROP_TABLE);
func_exit:
	mutex_exit(&row_drop_list_mutex);
	return added;
}

/** Reassigns the table identifier of a table.
@param[in,out]	table	table
@param[in,out]	trx	transaction
@param[out]	new_id	new table id
@return error code or DB_SUCCESS */
static
dberr_t
row_mysql_table_id_reassign(
	dict_table_t*	table,
	trx_t*		trx,
	table_id_t*	new_id)
{
	dberr_t		err;
	pars_info_t*	info	= pars_info_create();

	dict_hdr_get_new_id(new_id, NULL, NULL);

	pars_info_add_ull_literal(info, "old_id", table->id);
	pars_info_add_ull_literal(info, "new_id", *new_id);

	/* Note: This cannot be rolled back. Rollback would see the
	UPDATE SYS_INDEXES as two operations: DELETE and INSERT.
	It would invoke btr_free_if_exists() when rolling back the
	INSERT, effectively dropping all indexes of the table. */
	err = que_eval_sql(
		info,
		"PROCEDURE RENUMBER_TABLE_PROC () IS\n"
		"BEGIN\n"
		"UPDATE SYS_TABLES SET ID = :new_id\n"
		" WHERE ID = :old_id;\n"
		"UPDATE SYS_COLUMNS SET TABLE_ID = :new_id\n"
		" WHERE TABLE_ID = :old_id;\n"
		"UPDATE SYS_INDEXES SET TABLE_ID = :new_id\n"
		" WHERE TABLE_ID = :old_id;\n"
		"UPDATE SYS_VIRTUAL SET TABLE_ID = :new_id\n"
		" WHERE TABLE_ID = :old_id;\n"
		"END;\n", FALSE, trx);

	return(err);
}

/*********************************************************************//**
Setup the pre-requisites for DISCARD TABLESPACE. It will start the transaction,
acquire the data dictionary lock in X mode and open the table.
@return table instance or 0 if not found. */
static
dict_table_t*
row_discard_tablespace_begin(
/*=========================*/
	const char*	name,	/*!< in: table name */
	trx_t*		trx)	/*!< in: transaction handle */
{
	trx->op_info = "discarding tablespace";

	trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);

	trx_start_if_not_started_xa(trx, true);

	/* Serialize data dictionary operations with dictionary mutex:
	this is to avoid deadlocks during data dictionary operations */

	row_mysql_lock_data_dictionary(trx);

	dict_table_t*	table;

	table = dict_table_open_on_name(
		name, TRUE, FALSE, DICT_ERR_IGNORE_FK_NOKEY);

	if (table) {
		dict_stats_wait_bg_to_stop_using_table(table, trx);
		ut_a(!is_system_tablespace(table->space_id));
		ut_ad(!table->n_foreign_key_checks_running);
	}

	return(table);
}

/*********************************************************************//**
Do the foreign key constraint checks.
@return DB_SUCCESS or error code. */
static
dberr_t
row_discard_tablespace_foreign_key_checks(
/*======================================*/
	const trx_t*		trx,	/*!< in: transaction handle */
	const dict_table_t*	table)	/*!< in: table to be discarded */
{

	if (srv_read_only_mode || !trx->check_foreigns) {
		return(DB_SUCCESS);
	}

	/* Check if the table is referenced by foreign key constraints from
	some other table (not the table itself) */
	dict_foreign_set::const_iterator	it
		= std::find_if(table->referenced_set.begin(),
			       table->referenced_set.end(),
			       dict_foreign_different_tables());

	if (it == table->referenced_set.end()) {
		return(DB_SUCCESS);
	}

	const dict_foreign_t*	foreign	= *it;
	FILE*			ef	= dict_foreign_err_file;

	ut_ad(foreign->foreign_table != table);
	ut_ad(foreign->referenced_table == table);

	/* We only allow discarding a referenced table if
	FOREIGN_KEY_CHECKS is set to 0 */

	mutex_enter(&dict_foreign_err_mutex);

	rewind(ef);

	ut_print_timestamp(ef);

	fputs("  Cannot DISCARD table ", ef);
	ut_print_name(ef, trx, table->name.m_name);
	fputs("\n"
	      "because it is referenced by ", ef);
	ut_print_name(ef, trx, foreign->foreign_table_name);
	putc('\n', ef);

	mutex_exit(&dict_foreign_err_mutex);

	return(DB_CANNOT_DROP_CONSTRAINT);
}

/*********************************************************************//**
Cleanup after the DISCARD TABLESPACE operation.
@return error code. */
static
dberr_t
row_discard_tablespace_end(
/*=======================*/
	trx_t*		trx,	/*!< in/out: transaction handle */
	dict_table_t*	table,	/*!< in/out: table to be discarded */
	dberr_t		err)	/*!< in: error code */
{
	if (table != 0) {
		dict_table_close(table, TRUE, FALSE);
	}

	DBUG_EXECUTE_IF("ib_discard_before_commit_crash",
			log_buffer_flush_to_disk();
			DBUG_SUICIDE(););

	trx_commit_for_mysql(trx);

	DBUG_EXECUTE_IF("ib_discard_after_commit_crash",
			log_buffer_flush_to_disk();
			DBUG_SUICIDE(););

	row_mysql_unlock_data_dictionary(trx);

	trx->op_info = "";

	return(err);
}

/*********************************************************************//**
Do the DISCARD TABLESPACE operation.
@return DB_SUCCESS or error code. */
static
dberr_t
row_discard_tablespace(
/*===================*/
	trx_t*		trx,	/*!< in/out: transaction handle */
	dict_table_t*	table)	/*!< in/out: table to be discarded */
{
	dberr_t		err;

	/* How do we prevent crashes caused by ongoing operations on
	the table? Old operations could try to access non-existent
	pages. MySQL will block all DML on the table using MDL and a
	DISCARD will not start unless all existing operations on the
	table to be discarded are completed.

	1) Acquire the data dictionary latch in X mode. To prevent any
	internal operations that MySQL is not aware off and also for
	the internal SQL parser.

	2) Purge and rollback: we assign a new table id for the
	table. Since purge and rollback look for the table based on
	the table id, they see the table as 'dropped' and discard
	their operations.

	3) Insert buffer: we remove all entries for the tablespace in
	the insert buffer tree. */

	ibuf_delete_for_discarded_space(table->space_id);

	table_id_t	new_id;

	/* Set the TABLESPACE DISCARD flag in the table definition
	on disk. */
	err = row_import_update_discarded_flag(trx, table->id, true);

	if (err != DB_SUCCESS) {
		return(err);
	}

	/* Update the index root pages in the system tables, on disk */
	err = row_import_update_index_root(trx, table, true);

	if (err != DB_SUCCESS) {
		return(err);
	}

	/* Drop all the FTS auxiliary tables. */
	if (dict_table_has_fts_index(table)
	    || DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_HAS_DOC_ID)) {

		fts_drop_tables(trx, table);
	}

	/* Assign a new space ID to the table definition so that purge
	can ignore the changes. Update the system table on disk. */

	err = row_mysql_table_id_reassign(table, trx, &new_id);

	if (err != DB_SUCCESS) {
		return(err);
	}

	/* Discard the physical file that is used for the tablespace. */
	err = fil_delete_tablespace(table->space_id);
	switch (err) {
	case DB_IO_ERROR:
		ib::warn() << "ALTER TABLE " << table->name
			<< " DISCARD TABLESPACE failed to delete file";
		break;
	case DB_TABLESPACE_NOT_FOUND:
		ib::warn() << "ALTER TABLE " << table->name
			<< " DISCARD TABLESPACE failed to find tablespace";
		break;
	case DB_SUCCESS:
		break;
	default:
		ut_error;
	}

	/* All persistent operations successful, update the
	data dictionary memory cache. */

	table->file_unreadable = true;
	table->space = NULL;
	table->flags2 |= DICT_TF2_DISCARDED;
	dict_table_change_id_in_cache(table, new_id);

	dict_index_t* index = UT_LIST_GET_FIRST(table->indexes);
	if (index) index->clear_instant_alter();

	/* Reset the root page numbers. */
	for (; index; index = UT_LIST_GET_NEXT(indexes, index)) {
		index->page = FIL_NULL;
	}

	/* If the tablespace did not already exist or we couldn't
	write to it, we treat that as a successful DISCARD. It is
	unusable anyway. */
	return DB_SUCCESS;
}

/*********************************************************************//**
Discards the tablespace of a table which stored in an .ibd file. Discarding
means that this function renames the .ibd file and assigns a new table id for
the table. Also the file_unreadable flag is set.
@return error code or DB_SUCCESS */
dberr_t
row_discard_tablespace_for_mysql(
/*=============================*/
	const char*	name,	/*!< in: table name */
	trx_t*		trx)	/*!< in: transaction handle */
{
	dberr_t		err;
	dict_table_t*	table;

	/* Open the table and start the transaction if not started. */

	table = row_discard_tablespace_begin(name, trx);

	if (table == 0) {
		err = DB_TABLE_NOT_FOUND;
	} else if (table->is_temporary()) {

		ib_senderrf(trx->mysql_thd, IB_LOG_LEVEL_ERROR,
			    ER_CANNOT_DISCARD_TEMPORARY_TABLE);

		err = DB_ERROR;

	} else if (table->space_id == TRX_SYS_SPACE) {
		char	table_name[MAX_FULL_NAME_LEN + 1];

		innobase_format_name(
			table_name, sizeof(table_name),
			table->name.m_name);

		ib_senderrf(trx->mysql_thd, IB_LOG_LEVEL_ERROR,
			    ER_TABLE_IN_SYSTEM_TABLESPACE, table_name);

		err = DB_ERROR;

	} else {
		ut_ad(!table->n_foreign_key_checks_running);

		bool fts_exist = (dict_table_has_fts_index(table)
				  || DICT_TF2_FLAG_IS_SET(
					  table, DICT_TF2_FTS_HAS_DOC_ID));

		if (fts_exist) {
			row_mysql_unlock_data_dictionary(trx);
			fts_optimize_remove_table(table);
			row_mysql_lock_data_dictionary(trx);
		}

		/* Do foreign key constraint checks. */

		err = row_discard_tablespace_foreign_key_checks(trx, table);

		if (err == DB_SUCCESS) {
			/* Note: This cannot be rolled back.
			Rollback would see the UPDATE SYS_INDEXES
			as two operations: DELETE and INSERT.
			It would invoke btr_free_if_exists()
			when rolling back the INSERT, effectively
			dropping all indexes of the table. */
			err = row_discard_tablespace(trx, table);
		}

		if (fts_exist && err != DB_SUCCESS) {
			fts_optimize_add_table(table);
		}
	}

	return(row_discard_tablespace_end(trx, table, err));
}

/*********************************************************************//**
Sets an exclusive lock on a table.
@return error code or DB_SUCCESS */
dberr_t
row_mysql_lock_table(
/*=================*/
	trx_t*		trx,		/*!< in/out: transaction */
	dict_table_t*	table,		/*!< in: table to lock */
	enum lock_mode	mode,		/*!< in: LOCK_X or LOCK_S */
	const char*	op_info)	/*!< in: string for trx->op_info */
{
	mem_heap_t*	heap;
	que_thr_t*	thr;
	dberr_t		err;
	sel_node_t*	node;

	ut_ad(mode == LOCK_X || mode == LOCK_S);

	heap = mem_heap_create(512);

	trx->op_info = op_info;

	node = sel_node_create(heap);
	thr = pars_complete_graph_for_exec(node, trx, heap, NULL);
	thr->graph->state = QUE_FORK_ACTIVE;

	/* We use the select query graph as the dummy graph needed
	in the lock module call */

	thr = que_fork_get_first_thr(
		static_cast<que_fork_t*>(que_node_get_parent(thr)));

	thr->start_running();

run_again:
	thr->run_node = thr;
	thr->prev_node = thr->common.parent;

	err = lock_table(0, table, mode, thr);

	trx->error_state = err;

	if (err == DB_SUCCESS) {
		thr->stop_no_error();
	} else {
		que_thr_stop_for_mysql(thr);

		if (row_mysql_handle_errors(&err, trx, thr, NULL)) {
			goto run_again;
		}
	}

	que_graph_free(thr->graph);
	trx->op_info = "";

	return(err);
}

/** Drop ancillary FTS tables as part of dropping a table.
@param[in,out]	table		Table cache entry
@param[in,out]	trx		Transaction handle
@return error code or DB_SUCCESS */
UNIV_INLINE
dberr_t
row_drop_ancillary_fts_tables(
	dict_table_t*	table,
	trx_t*		trx)
{
	/* Drop ancillary FTS tables */
	if (dict_table_has_fts_index(table)
	    || DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_HAS_DOC_ID)) {

		ut_ad(table->get_ref_count() == 0);
		ut_ad(trx_is_started(trx));

		dberr_t err = fts_drop_tables(trx, table);

		if (UNIV_UNLIKELY(err != DB_SUCCESS)) {
			ib::error() << " Unable to remove ancillary FTS"
				" tables for table "
				<< table->name << " : " << err;

			return(err);
		}
	}

	/* The table->fts flag can be set on the table for which
	the cluster index is being rebuilt. Such table might not have
	DICT_TF2_FTS flag set. So keep this out of above
	dict_table_has_fts_index condition */
	if (table->fts != NULL) {
		/* fts_que_graph_free_check_lock would try to acquire
		dict mutex lock */
		table->fts->dict_locked = true;

		fts_free(table);
	}

	return(DB_SUCCESS);
}

/** Drop a table from the memory cache as part of dropping a table.
@param[in]	tablename	A copy of table->name. Used when table == null
@param[in,out]	table		Table cache entry
@param[in,out]	trx		Transaction handle
@return error code or DB_SUCCESS */
UNIV_INLINE
dberr_t
row_drop_table_from_cache(
	const char*	tablename,
	dict_table_t*	table,
	trx_t*		trx)
{
	dberr_t	err = DB_SUCCESS;
	ut_ad(!table->is_temporary());

	/* Remove the pointer to this table object from the list
	of modified tables by the transaction because the object
	is going to be destroyed below. */
	trx->mod_tables.erase(table);

	dict_sys.remove(table);

	if (dict_load_table(tablename, DICT_ERR_IGNORE_FK_NOKEY)) {
		ib::error() << "Not able to remove table "
			<< ut_get_name(trx, tablename)
			<< " from the dictionary cache!";
		err = DB_ERROR;
	}

	return(err);
}

/** Drop a table for MySQL.
If the data dictionary was not already locked by the transaction,
the transaction will be committed.  Otherwise, the data dictionary
will remain locked.
@param[in]	name		Table name
@param[in,out]	trx		Transaction handle
@param[in]	sqlcom		type of SQL operation
@param[in]	create_failed	true=create table failed
				because e.g. foreign key column
@param[in]	nonatomic	Whether it is permitted to release
				and reacquire dict_sys.latch
@return error code or DB_SUCCESS */
dberr_t
row_drop_table_for_mysql(
	const char*		name,
	trx_t*			trx,
	enum_sql_command	sqlcom,
	bool			create_failed,
	bool			nonatomic)
{
	dberr_t		err;
	dict_foreign_t*	foreign;
	dict_table_t*	table;
	char*		tablename		= NULL;
	bool		locked_dictionary	= false;
	pars_info_t*	info			= NULL;
	mem_heap_t*	heap			= NULL;


	DBUG_ENTER("row_drop_table_for_mysql");
	DBUG_PRINT("row_drop_table_for_mysql", ("table: '%s'", name));

	ut_a(name != NULL);

	/* Serialize data dictionary operations with dictionary mutex:
	no deadlocks can occur then in these operations */

	trx->op_info = "dropping table";

	if (trx->dict_operation_lock_mode != RW_X_LATCH) {
		/* Prevent foreign key checks etc. while we are
		dropping the table */

		row_mysql_lock_data_dictionary(trx);

		locked_dictionary = true;
		nonatomic = true;
	}

	ut_d(dict_sys.assert_locked());

	table = dict_table_open_on_name(
		name, TRUE, FALSE,
		static_cast<dict_err_ignore_t>(
			DICT_ERR_IGNORE_INDEX_ROOT
			| DICT_ERR_IGNORE_CORRUPT));

	if (!table) {
		if (locked_dictionary) {
			row_mysql_unlock_data_dictionary(trx);
		}
		trx->op_info = "";
		DBUG_RETURN(DB_TABLE_NOT_FOUND);
	}

	std::vector<pfs_os_file_t> detached_handles;

	const bool is_temp_name = strstr(table->name.m_name,
					 "/" TEMP_FILE_PREFIX);

	if (table->is_temporary()) {
		ut_ad(table->space == fil_system.temp_space);
		for (dict_index_t* index = dict_table_get_first_index(table);
		     index != NULL;
		     index = dict_table_get_next_index(index)) {
			btr_free(page_id_t(SRV_TMP_SPACE_ID, index->page));
		}
		/* Remove the pointer to this table object from the list
		of modified tables by the transaction because the object
		is going to be destroyed below. */
		trx->mod_tables.erase(table);
		table->release();
		dict_sys.remove(table);
		err = DB_SUCCESS;
		goto funct_exit_all_freed;
	}

	/* This function is called recursively via fts_drop_tables(). */
	if (!trx_is_started(trx)) {
		trx_start_for_ddl(trx, TRX_DICT_OP_TABLE);
	}

	/* Turn on this drop bit before we could release the dictionary
	latch */
	table->to_be_dropped = true;

	if (nonatomic) {
		/* This trx did not acquire any locks on dictionary
		table records yet. Thus it is safe to release and
		reacquire the data dictionary latches. */
		if (table->fts) {
			row_mysql_unlock_data_dictionary(trx);
			fts_optimize_remove_table(table);
			row_mysql_lock_data_dictionary(trx);
		}

		dict_stats_wait_bg_to_stop_using_table(table, trx);
	}

	/* make sure background stats thread is not running on the table */
	ut_ad(!(table->stats_bg_flag & BG_STAT_IN_PROGRESS));
	if (!table->no_rollback()) {
		if (table->space != fil_system.sys_space) {
			/* Delete the link file if used. */
			if (DICT_TF_HAS_DATA_DIR(table->flags)) {
				RemoteDatafile::delete_link_file(name);
			}
		}

		dict_stats_recalc_pool_del(table);
		dict_stats_defrag_pool_del(table, NULL);
		if (btr_defragment_active) {
			/* During fts_drop_orphaned_tables() the
			btr_defragment_mutex has not yet been
			initialized by btr_defragment_init(). */
			btr_defragment_remove_table(table);
		}

		if (UNIV_LIKELY(!strstr(name, "/" TEMP_FILE_PREFIX_INNODB))) {
			/* Remove any persistent statistics for this table,
			in a separate transaction. */
			char errstr[1024];
			err = dict_stats_drop_table(name, errstr,
						    sizeof errstr);
			if (err != DB_SUCCESS) {
				ib::warn() << errstr;
			}
		}
	}

	dict_table_prevent_eviction(table);
	dict_table_close(table, TRUE, FALSE);

	/* Check if the table is referenced by foreign key constraints from
	some other table (not the table itself) */

	if (!srv_read_only_mode && trx->check_foreigns) {

		for (dict_foreign_set::iterator it
			= table->referenced_set.begin();
		     it != table->referenced_set.end();
		     ++it) {

			foreign = *it;

			const bool	ref_ok = sqlcom == SQLCOM_DROP_DB
				&& dict_tables_have_same_db(
					name,
					foreign->foreign_table_name_lookup);

			/* We should allow dropping a referenced table if creating
			that referenced table has failed for some reason. For example
			if referenced table is created but it column types that are
			referenced do not match. */
			if (foreign->foreign_table != table &&
			    !create_failed && !ref_ok) {

				FILE*	ef	= dict_foreign_err_file;

				/* We only allow dropping a referenced table
				if FOREIGN_KEY_CHECKS is set to 0 */

				err = DB_CANNOT_DROP_CONSTRAINT;

				mutex_enter(&dict_foreign_err_mutex);
				rewind(ef);
				ut_print_timestamp(ef);

				fputs("  Cannot drop table ", ef);
				ut_print_name(ef, trx, name);
				fputs("\n"
				      "because it is referenced by ", ef);
				ut_print_name(ef, trx,
					      foreign->foreign_table_name);
				putc('\n', ef);
				mutex_exit(&dict_foreign_err_mutex);

				goto funct_exit;
			}
		}
	}

	DBUG_EXECUTE_IF("row_drop_table_add_to_background", goto defer;);

	/* TODO: could we replace the counter n_foreign_key_checks_running
	with lock checks on the table? Acquire here an exclusive lock on the
	table, and rewrite lock0lock.cc and the lock wait in srv0srv.cc so that
	they can cope with the table having been dropped here? Foreign key
	checks take an IS or IX lock on the table. */

	if (table->n_foreign_key_checks_running > 0) {
defer:
		/* Rename #sql-backup to #sql-ib if table has open ref count
		while dropping the table. This scenario can happen
		when purge thread is waiting for dict_sys.mutex so
		that it could close the table. But drop table acquires
		dict_sys.mutex.
                In the future this should use 'tmp_file_prefix'!
                */
		if (!is_temp_name
		    || strstr(table->name.m_name, "/#sql-backup-")) {
			heap = mem_heap_create(FN_REFLEN);
			const char* tmp_name
				= dict_mem_create_temporary_tablename(
					heap, table->name.m_name, table->id);
			ib::info() << "Deferring DROP TABLE " << table->name
				   << "; renaming to " << tmp_name;
			err = row_rename_table_for_mysql(
				table->name.m_name, tmp_name, trx,
				false, false);
		} else {
			err = DB_SUCCESS;
		}
		if (err == DB_SUCCESS) {
			row_add_table_to_background_drop_list(table->id);
		}
		goto funct_exit;
	}

	/* Remove all locks that are on the table or its records, if there
	are no references to the table but it has record locks, we release
	the record locks unconditionally. One use case is:

		CREATE TABLE t2 (PRIMARY KEY (a)) SELECT * FROM t1;

	If after the user transaction has done the SELECT and there is a
	problem in completing the CREATE TABLE operation, MySQL will drop
	the table. InnoDB will create a new background transaction to do the
	actual drop, the trx instance that is passed to this function. To
	preserve existing behaviour we remove the locks but ideally we
	shouldn't have to. There should never be record locks on a table
	that is going to be dropped. */

	if (table->get_ref_count() > 0 || table->n_rec_locks > 0
	    || lock_table_has_locks(table)) {
		goto defer;
	}

	/* The "to_be_dropped" marks table that is to be dropped, but
	has not been dropped, instead, was put in the background drop
	list due to being used by concurrent DML operations. Clear it
	here since there are no longer any concurrent activities on it,
	and it is free to be dropped */
	table->to_be_dropped = false;

	switch (trx_get_dict_operation(trx)) {
	case TRX_DICT_OP_NONE:
		trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);
		trx->table_id = table->id;
	case TRX_DICT_OP_TABLE:
		break;
	case TRX_DICT_OP_INDEX:
		/* If the transaction was previously flagged as
		TRX_DICT_OP_INDEX, we should be dropping auxiliary
		tables for full-text indexes. */
		ut_ad(strstr(table->name.m_name, "/FTS_"));
	}

	/* Mark all indexes unavailable in the data dictionary cache
	before starting to drop the table. */

	unsigned*	page_no;
	unsigned*	page_nos;
	heap = mem_heap_create(
		200 + UT_LIST_GET_LEN(table->indexes) * sizeof *page_nos);
	tablename = mem_heap_strdup(heap, name);

	page_no = page_nos = static_cast<unsigned*>(
		mem_heap_alloc(
			heap,
			UT_LIST_GET_LEN(table->indexes) * sizeof *page_no));

	for (dict_index_t* index = dict_table_get_first_index(table);
	     index != NULL;
	     index = dict_table_get_next_index(index)) {
		rw_lock_x_lock(dict_index_get_lock(index));
		/* Save the page numbers so that we can restore them
		if the operation fails. */
		*page_no++ = index->page;
		/* Mark the index unusable. */
		index->page = FIL_NULL;
		rw_lock_x_unlock(dict_index_get_lock(index));
	}

	/* Deleting a row from SYS_INDEXES table will invoke
	dict_drop_index_tree(). */
	info = pars_info_create();

	pars_info_add_str_literal(info, "name", name);

	if (sqlcom != SQLCOM_TRUNCATE
	    && strchr(name, '/')
	    && dict_table_get_low("SYS_FOREIGN")
	    && dict_table_get_low("SYS_FOREIGN_COLS")) {
		err = que_eval_sql(
			info,
			"PROCEDURE DROP_FOREIGN_PROC () IS\n"
			"fid CHAR;\n"

			"DECLARE CURSOR fk IS\n"
			"SELECT ID FROM SYS_FOREIGN\n"
			"WHERE FOR_NAME = :name\n"
			"AND TO_BINARY(FOR_NAME) = TO_BINARY(:name)\n"
			"FOR UPDATE;\n"

			"BEGIN\n"
			"OPEN fk;\n"
			"WHILE 1 = 1 LOOP\n"
			"  FETCH fk INTO fid;\n"
			"  IF (SQL % NOTFOUND) THEN RETURN; END IF;\n"
			"  DELETE FROM SYS_FOREIGN_COLS WHERE ID=fid;\n"
			"  DELETE FROM SYS_FOREIGN WHERE ID=fid;\n"
			"END LOOP;\n"
			"CLOSE fk;\n"
			"END;\n", FALSE, trx);
		if (err == DB_SUCCESS) {
			info = pars_info_create();
			pars_info_add_str_literal(info, "name", name);
			goto do_drop;
		}
	} else {
do_drop:
		if (dict_table_get_low("SYS_VIRTUAL")) {
			err = que_eval_sql(
				info,
				"PROCEDURE DROP_VIRTUAL_PROC () IS\n"
				"tid CHAR;\n"

				"BEGIN\n"
				"SELECT ID INTO tid FROM SYS_TABLES\n"
				"WHERE NAME = :name FOR UPDATE;\n"
				"IF (SQL % NOTFOUND) THEN RETURN;"
				" END IF;\n"
				"DELETE FROM SYS_VIRTUAL"
				" WHERE TABLE_ID = tid;\n"
				"END;\n", FALSE, trx);
			if (err == DB_SUCCESS) {
				info = pars_info_create();
				pars_info_add_str_literal(
					info, "name", name);
			}
		} else {
			err = DB_SUCCESS;
		}

		err = err == DB_SUCCESS ? que_eval_sql(
			info,
			"PROCEDURE DROP_TABLE_PROC () IS\n"
			"tid CHAR;\n"
			"iid CHAR;\n"

			"DECLARE CURSOR cur_idx IS\n"
			"SELECT ID FROM SYS_INDEXES\n"
			"WHERE TABLE_ID = tid FOR UPDATE;\n"

			"BEGIN\n"
			"SELECT ID INTO tid FROM SYS_TABLES\n"
			"WHERE NAME = :name FOR UPDATE;\n"
			"IF (SQL % NOTFOUND) THEN RETURN; END IF;\n"

			"OPEN cur_idx;\n"
			"WHILE 1 = 1 LOOP\n"
			"  FETCH cur_idx INTO iid;\n"
			"  IF (SQL % NOTFOUND) THEN EXIT; END IF;\n"
			"  DELETE FROM SYS_FIELDS\n"
			"  WHERE INDEX_ID = iid;\n"
			"  DELETE FROM SYS_INDEXES\n"
			"  WHERE ID = iid AND TABLE_ID = tid;\n"
			"END LOOP;\n"
			"CLOSE cur_idx;\n"

			"DELETE FROM SYS_COLUMNS WHERE TABLE_ID=tid;\n"
			"DELETE FROM SYS_TABLES WHERE NAME=:name;\n"

			"END;\n", FALSE, trx) : err;

		if (err == DB_SUCCESS && table->space
		    && dict_table_get_low("SYS_TABLESPACES")
		    && dict_table_get_low("SYS_DATAFILES")) {
			info = pars_info_create();
			pars_info_add_int4_literal(info, "id",
						   lint(table->space_id));
			err = que_eval_sql(
				info,
				"PROCEDURE DROP_SPACE_PROC () IS\n"
				"BEGIN\n"
				"DELETE FROM SYS_TABLESPACES\n"
				"WHERE SPACE = :id;\n"
				"DELETE FROM SYS_DATAFILES\n"
				"WHERE SPACE = :id;\n"
				"END;\n", FALSE, trx);
		}
	}

	switch (err) {
		fil_space_t* space;
		char* filepath;
	case DB_SUCCESS:
		if (!table->no_rollback()) {
			err = row_drop_ancillary_fts_tables(table, trx);
			if (err != DB_SUCCESS) {
				break;
			}
		}

		space = table->space;
		ut_ad(!space || space->id == table->space_id);
		/* Determine the tablespace filename before we drop
		dict_table_t. */
		if (DICT_TF_HAS_DATA_DIR(table->flags)) {
			dict_get_and_save_data_dir_path(table, true);
			ut_ad(table->data_dir_path || !space);
			filepath = space ? NULL : fil_make_filepath(
				table->data_dir_path,
				table->name.m_name, IBD,
				table->data_dir_path != NULL);
		} else {
			filepath = space ? NULL : fil_make_filepath(
				NULL, table->name.m_name, IBD, false);
		}

		/* Free the dict_table_t object. */
		err = row_drop_table_from_cache(tablename, table, trx);
		if (err != DB_SUCCESS) {
			ut_free(filepath);
			break;
		}

		/* Do not attempt to drop known-to-be-missing tablespaces,
		nor the system tablespace. */
		if (!space) {
			fil_delete_file(filepath);
			ut_free(filepath);
			break;
		}

		ut_ad(!filepath);

		if (space->id != TRX_SYS_SPACE) {
			err = fil_delete_tablespace(space->id, false,
						    &detached_handles);
		}
		break;

	case DB_OUT_OF_FILE_SPACE:
		err = DB_MUST_GET_MORE_FILE_SPACE;
		trx->error_state = err;
		row_mysql_handle_errors(&err, trx, NULL, NULL);

		/* raise error */
		ut_error;
		break;

	case DB_TOO_MANY_CONCURRENT_TRXS:
		/* Cannot even find a free slot for the
		the undo log. We can directly exit here
		and return the DB_TOO_MANY_CONCURRENT_TRXS
		error. */

	default:
		/* This is some error we do not expect. Print
		the error number and rollback the transaction */
		ib::error() << "Unknown error code " << err << " while"
			" dropping table: "
			<< ut_get_name(trx, tablename) << ".";

		trx->error_state = DB_SUCCESS;
		trx->rollback();
		trx->error_state = DB_SUCCESS;

		/* Mark all indexes available in the data dictionary
		cache again. */

		page_no = page_nos;

		for (dict_index_t* index = dict_table_get_first_index(table);
		     index != NULL;
		     index = dict_table_get_next_index(index)) {
			rw_lock_x_lock(dict_index_get_lock(index));
			ut_a(index->page == FIL_NULL);
			index->page = *page_no++;
			rw_lock_x_unlock(dict_index_get_lock(index));
		}
	}

	if (err != DB_SUCCESS && table != NULL) {
		/* Drop table has failed with error but as drop table is not
		transaction safe we should mark the table as corrupted to avoid
		unwarranted follow-up action on this table that can result
		in more serious issues. */

		table->corrupted = true;
		for (dict_index_t* index = UT_LIST_GET_FIRST(table->indexes);
		     index != NULL;
		     index = UT_LIST_GET_NEXT(indexes, index)) {
			dict_set_corrupted(index, trx, "DROP TABLE");
		}
	}

funct_exit:
	if (heap) {
		mem_heap_free(heap);
	}

funct_exit_all_freed:
	if (locked_dictionary) {

		if (trx_is_started(trx)) {

			trx_commit_for_mysql(trx);
		}

		/* Add the table to fts queue if drop table fails */
		if (err != DB_SUCCESS && table->fts) {
			fts_optimize_add_table(table);
		}

		row_mysql_unlock_data_dictionary(trx);
	}

	for (const auto& handle : detached_handles) {
		ut_ad(handle != OS_FILE_CLOSED);
		os_file_close(handle);
	}

	trx->op_info = "";

	DBUG_RETURN(err);
}

/** Drop a table after failed CREATE TABLE. */
dberr_t row_drop_table_after_create_fail(const char* name, trx_t* trx)
{
	ib::warn() << "Dropping incompletely created " << name << " table.";
	return row_drop_table_for_mysql(name, trx, SQLCOM_DROP_DB, true);
}

/*******************************************************************//**
Drop all foreign keys in a database, see Bug#18942.
Called at the end of row_drop_database_for_mysql().
@return error code or DB_SUCCESS */
static MY_ATTRIBUTE((nonnull, warn_unused_result))
dberr_t
drop_all_foreign_keys_in_db(
/*========================*/
	const char*	name,	/*!< in: database name which ends to '/' */
	trx_t*		trx)	/*!< in: transaction handle */
{
	pars_info_t*	pinfo;
	dberr_t		err;

	ut_a(name[strlen(name) - 1] == '/');

	pinfo = pars_info_create();

	pars_info_add_str_literal(pinfo, "dbname", name);

/** true if for_name is not prefixed with dbname */
#define TABLE_NOT_IN_THIS_DB \
"SUBSTR(for_name, 0, LENGTH(:dbname)) <> :dbname"

	err = que_eval_sql(pinfo,
			   "PROCEDURE DROP_ALL_FOREIGN_KEYS_PROC () IS\n"
			   "foreign_id CHAR;\n"
			   "for_name CHAR;\n"
			   "found INT;\n"
			   "DECLARE CURSOR cur IS\n"
			   "SELECT ID, FOR_NAME FROM SYS_FOREIGN\n"
			   "WHERE FOR_NAME >= :dbname\n"
			   "LOCK IN SHARE MODE\n"
			   "ORDER BY FOR_NAME;\n"
			   "BEGIN\n"
			   "found := 1;\n"
			   "OPEN cur;\n"
			   "WHILE found = 1 LOOP\n"
			   "        FETCH cur INTO foreign_id, for_name;\n"
			   "        IF (SQL % NOTFOUND) THEN\n"
			   "                found := 0;\n"
			   "        ELSIF (" TABLE_NOT_IN_THIS_DB ") THEN\n"
			   "                found := 0;\n"
			   "        ELSIF (1=1) THEN\n"
			   "                DELETE FROM SYS_FOREIGN_COLS\n"
			   "                WHERE ID = foreign_id;\n"
			   "                DELETE FROM SYS_FOREIGN\n"
			   "                WHERE ID = foreign_id;\n"
			   "        END IF;\n"
			   "END LOOP;\n"
			   "CLOSE cur;\n"
			   "COMMIT WORK;\n"
			   "END;\n",
			   FALSE, /* do not reserve dict mutex,
				  we are already holding it */
			   trx);

	return(err);
}

/** Drop a database for MySQL.
@param[in]	name	database name which ends at '/'
@param[in]	trx	transaction handle
@param[out]	found	number of dropped tables/partitions
@return error code or DB_SUCCESS */
dberr_t
row_drop_database_for_mysql(
	const char*	name,
	trx_t*		trx,
	ulint*		found)
{
	dict_table_t*	table;
	char*		table_name;
	dberr_t		err	= DB_SUCCESS;
	ulint		namelen	= strlen(name);
	bool		is_partition = false;

	ut_ad(found != NULL);

	DBUG_ENTER("row_drop_database_for_mysql");

	DBUG_PRINT("row_drop_database_for_mysql", ("db: '%s'", name));

	ut_a(name != NULL);
	/* Assert DB name or partition name. */
	if (name[namelen - 1] == '#') {
		ut_ad(name[namelen - 2] != '/');
		is_partition = true;
		trx->op_info = "dropping partitions";
	} else {
		ut_a(name[namelen - 1] == '/');
		trx->op_info = "dropping database";
	}

	*found = 0;

	trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);

	trx_start_if_not_started_xa(trx, true);

loop:
	row_mysql_lock_data_dictionary(trx);

	while ((table_name = dict_get_first_table_name_in_db(name))) {
		/* Drop parent table if it is a fts aux table, to
		avoid accessing dropped fts aux tables in information
		scheam when parent table still exists.
		Note: Drop parent table will drop fts aux tables. */
		char*		parent_table_name = NULL;
		table_id_t	table_id;
		index_id_t	index_id;

		if (fts_check_aux_table(
				table_name, &table_id, &index_id)) {
			dict_table_t* parent_table = dict_table_open_on_id(
					table_id, TRUE, DICT_TABLE_OP_NORMAL);
			if (parent_table != NULL) {
				parent_table_name = mem_strdupl(
					parent_table->name.m_name,
					strlen(parent_table->name.m_name));
				dict_table_close(parent_table, TRUE, FALSE);
			}
		}

		if (parent_table_name != NULL) {
			ut_free(table_name);
			table_name = parent_table_name;
		}

		ut_a(memcmp(table_name, name, namelen) == 0);

		table = dict_table_open_on_name(
			table_name, TRUE, FALSE, static_cast<dict_err_ignore_t>(
				DICT_ERR_IGNORE_INDEX_ROOT
				| DICT_ERR_IGNORE_CORRUPT));

		if (!table) {
			ib::error() << "Cannot load table " << table_name
				<< " from InnoDB internal data dictionary"
				" during drop database";
			ut_free(table_name);
			err = DB_TABLE_NOT_FOUND;
			break;

		}

		if (!table->name.is_temporary()) {
			/* There could be orphan temp tables left from
			interrupted alter table. Leave them, and handle
			the rest.*/
			if (table->can_be_evicted
			    && (name[namelen - 1] != '#')) {
				ib::warn() << "Orphan table encountered during"
					" DROP DATABASE. This is possible if '"
					<< table->name << ".frm' was lost.";
			}

			if (!table->is_readable() && !table->space) {
				ib::warn() << "Missing .ibd file for table "
					<< table->name << ".";
			}
		}

		dict_table_close(table, TRUE, FALSE);

		/* The dict_table_t object must not be accessed before
		dict_table_open() or after dict_table_close(). But this is OK
		if we are holding, the dict_sys.mutex. */
		ut_ad(mutex_own(&dict_sys.mutex));

		/* Disable statistics on the found table. */
		if (!dict_stats_stop_bg(table)) {
			row_mysql_unlock_data_dictionary(trx);

			os_thread_sleep(250000);

			ut_free(table_name);

			goto loop;
		}

		/* Wait until MySQL does not have any queries running on
		the table */

		if (table->get_ref_count() > 0) {
			row_mysql_unlock_data_dictionary(trx);

			ib::warn() << "MySQL is trying to drop database "
				<< ut_get_name(trx, name) << " though"
				" there are still open handles to table "
				<< table->name << ".";

			os_thread_sleep(1000000);

			ut_free(table_name);

			goto loop;
		}

		err = row_drop_table_for_mysql(
			table_name, trx, SQLCOM_DROP_DB);
		trx_commit_for_mysql(trx);

		if (UNIV_UNLIKELY(err != DB_SUCCESS)) {
			ib::error() << "DROP DATABASE "
				<< ut_get_name(trx, name) << " failed"
				" with error (" << err << ") for"
				" table " << ut_get_name(trx, table_name);
			ut_free(table_name);
			break;
		}

		ut_free(table_name);
		(*found)++;
	}

	/* Partitioning does not yet support foreign keys. */
	if (err == DB_SUCCESS && !is_partition) {
		/* after dropping all tables try to drop all leftover
		foreign keys in case orphaned ones exist */
		err = drop_all_foreign_keys_in_db(name, trx);

		if (err != DB_SUCCESS) {
			const std::string&	db = ut_get_name(trx, name);
			ib::error() << "DROP DATABASE " << db << " failed with"
				" error " << err << " while dropping all"
				" foreign keys";
		}
	}

	trx_commit_for_mysql(trx);

	row_mysql_unlock_data_dictionary(trx);

	trx->op_info = "";

	DBUG_RETURN(err);
}

/****************************************************************//**
Delete a single constraint.
@return error code or DB_SUCCESS */
static MY_ATTRIBUTE((nonnull, warn_unused_result))
dberr_t
row_delete_constraint_low(
/*======================*/
	const char*	id,		/*!< in: constraint id */
	trx_t*		trx)		/*!< in: transaction handle */
{
	pars_info_t*	info = pars_info_create();

	pars_info_add_str_literal(info, "id", id);

	return(que_eval_sql(info,
			    "PROCEDURE DELETE_CONSTRAINT () IS\n"
			    "BEGIN\n"
			    "DELETE FROM SYS_FOREIGN_COLS WHERE ID = :id;\n"
			    "DELETE FROM SYS_FOREIGN WHERE ID = :id;\n"
			    "END;\n"
			    , FALSE, trx));
}

/****************************************************************//**
Delete a single constraint.
@return error code or DB_SUCCESS */
static MY_ATTRIBUTE((nonnull, warn_unused_result))
dberr_t
row_delete_constraint(
/*==================*/
	const char*	id,		/*!< in: constraint id */
	const char*	database_name,	/*!< in: database name, with the
					trailing '/' */
	mem_heap_t*	heap,		/*!< in: memory heap */
	trx_t*		trx)		/*!< in: transaction handle */
{
	dberr_t	err;

	/* New format constraints have ids <databasename>/<constraintname>. */
	err = row_delete_constraint_low(
		mem_heap_strcat(heap, database_name, id), trx);

	if ((err == DB_SUCCESS) && !strchr(id, '/')) {
		/* Old format < 4.0.18 constraints have constraint ids
		NUMBER_NUMBER. We only try deleting them if the
		constraint name does not contain a '/' character, otherwise
		deleting a new format constraint named 'foo/bar' from
		database 'baz' would remove constraint 'bar' from database
		'foo', if it existed. */

		err = row_delete_constraint_low(id, trx);
	}

	return(err);
}

/*********************************************************************//**
Renames a table for MySQL.
@return error code or DB_SUCCESS */
dberr_t
row_rename_table_for_mysql(
/*=======================*/
	const char*	old_name,	/*!< in: old table name */
	const char*	new_name,	/*!< in: new table name */
	trx_t*		trx,		/*!< in/out: transaction */
	bool		commit,		/*!< in: whether to commit trx */
	bool		use_fk)		/*!< in: whether to parse and enforce
					FOREIGN KEY constraints */
{
	dict_table_t*	table			= NULL;
	dberr_t		err			= DB_ERROR;
	mem_heap_t*	heap			= NULL;
	const char**	constraints_to_drop	= NULL;
	ulint		n_constraints_to_drop	= 0;
	ibool		old_is_tmp, new_is_tmp;
	pars_info_t*	info			= NULL;
	int		retry;
	bool		aux_fts_rename		= false;
	char*		is_part 		= NULL;

	ut_a(old_name != NULL);
	ut_a(new_name != NULL);
	ut_ad(trx->state == TRX_STATE_ACTIVE);
	const bool dict_locked = trx->dict_operation_lock_mode == RW_X_LATCH;
	ut_ad(!commit || dict_locked);

	if (high_level_read_only) {
		return(DB_READ_ONLY);
	}

	trx->op_info = "renaming table";

	old_is_tmp = dict_table_t::is_temporary_name(old_name);
	new_is_tmp = dict_table_t::is_temporary_name(new_name);

	table = dict_table_open_on_name(old_name, dict_locked, FALSE,
					DICT_ERR_IGNORE_FK_NOKEY);

	/* We look for pattern #P# to see if the table is partitioned
	MySQL table. */
#ifdef __WIN__
	is_part = strstr((char *)old_name, (char *)"#p#");
#else
	is_part = strstr((char *)old_name, (char *)"#P#");
#endif /* __WIN__ */

	/* MySQL partition engine hard codes the file name
	separator as "#P#". The text case is fixed even if
	lower_case_table_names is set to 1 or 2. This is true
	for sub-partition names as well. InnoDB always
	normalises file names to lower case on Windows, this
	can potentially cause problems when copying/moving
	tables between platforms.

	1) If boot against an installation from Windows
	platform, then its partition table name could
	be all be in lower case in system tables. So we
	will need to check lower case name when load table.

	2) If  we boot an installation from other case
	sensitive platform in Windows, we might need to
	check the existence of table name without lowering
	case them in the system table. */
	if (!table &&
	    is_part &&
	    innobase_get_lower_case_table_names() == 1) {
		char par_case_name[MAX_FULL_NAME_LEN + 1];
#ifndef __WIN__
		/* Check for the table using lower
		case name, including the partition
		separator "P" */
		memcpy(par_case_name, old_name,
			strlen(old_name));
		par_case_name[strlen(old_name)] = 0;
		innobase_casedn_str(par_case_name);
#else
		/* On Windows platfrom, check
		whether there exists table name in
		system table whose name is
		not being normalized to lower case */
		normalize_table_name_c_low(
			par_case_name, old_name, FALSE);
#endif
		table = dict_table_open_on_name(par_case_name, dict_locked, FALSE,
						DICT_ERR_IGNORE_FK_NOKEY);
	}

	if (!table) {
		err = DB_TABLE_NOT_FOUND;
		goto funct_exit;

	} else if (!table->is_readable() && !table->space
		   && !(table->flags2 & DICT_TF2_DISCARDED)) {

		err = DB_TABLE_NOT_FOUND;

		ib::error() << "Table " << old_name << " does not have an .ibd"
			" file in the database directory. "
			<< TROUBLESHOOTING_MSG;

		goto funct_exit;

	} else if (use_fk && !old_is_tmp && new_is_tmp) {
		/* MySQL is doing an ALTER TABLE command and it renames the
		original table to a temporary table name. We want to preserve
		the original foreign key constraint definitions despite the
		name change. An exception is those constraints for which
		the ALTER TABLE contained DROP FOREIGN KEY <foreign key id>.*/

		heap = mem_heap_create(100);

		err = dict_foreign_parse_drop_constraints(
			heap, trx, table, &n_constraints_to_drop,
			&constraints_to_drop);

		if (err != DB_SUCCESS) {
			goto funct_exit;
		}
	}

	/* Is a foreign key check running on this table? */
	for (retry = 0; retry < 100
	     && table->n_foreign_key_checks_running > 0; ++retry) {
		row_mysql_unlock_data_dictionary(trx);
		os_thread_yield();
		row_mysql_lock_data_dictionary(trx);
	}

	if (table->n_foreign_key_checks_running > 0) {
		ib::error() << "In ALTER TABLE "
			<< ut_get_name(trx, old_name)
			<< " a FOREIGN KEY check is running. Cannot rename"
			" table.";
		err = DB_TABLE_IN_FK_CHECK;
		goto funct_exit;
	}

	if (!table->is_temporary()) {
		if (commit) {
			dict_stats_wait_bg_to_stop_using_table(table, trx);
		}

		err = trx_undo_report_rename(trx, table);

		if (err != DB_SUCCESS) {
			goto funct_exit;
		}
	}

	/* We use the private SQL parser of Innobase to generate the query
	graphs needed in updating the dictionary data from system tables. */

	info = pars_info_create();

	pars_info_add_str_literal(info, "new_table_name", new_name);
	pars_info_add_str_literal(info, "old_table_name", old_name);

	err = que_eval_sql(info,
			   "PROCEDURE RENAME_TABLE () IS\n"
			   "BEGIN\n"
			   "UPDATE SYS_TABLES"
			   " SET NAME = :new_table_name\n"
			   " WHERE NAME = :old_table_name;\n"
			   "END;\n"
			   , FALSE, trx);

	/* Assume the caller guarantees destination name doesn't exist. */
	ut_ad(err != DB_DUPLICATE_KEY);

	/* SYS_TABLESPACES and SYS_DATAFILES need to be updated if
	the table is in a single-table tablespace. */
	if (err != DB_SUCCESS || !dict_table_is_file_per_table(table)) {
	} else if (table->space) {
		/* If old path and new path are the same means tablename
		has not changed and only the database name holding the table
		has changed so we need to make the complete filepath again. */
		char*	new_path = dict_tables_have_same_db(old_name, new_name)
			? os_file_make_new_pathname(
				table->space->chain.start->name, new_name)
			: fil_make_filepath(NULL, new_name, IBD, false);

		info = pars_info_create();

		pars_info_add_str_literal(info, "new_table_name", new_name);
		pars_info_add_str_literal(info, "new_path_name", new_path);
		pars_info_add_int4_literal(info, "space_id", table->space_id);

		err = que_eval_sql(info,
				   "PROCEDURE RENAME_SPACE () IS\n"
				   "BEGIN\n"
				   "UPDATE SYS_TABLESPACES"
				   " SET NAME = :new_table_name\n"
				   " WHERE SPACE = :space_id;\n"
				   "UPDATE SYS_DATAFILES"
				   " SET PATH = :new_path_name\n"
				   " WHERE SPACE = :space_id;\n"
				   "END;\n"
				   , FALSE, trx);

		ut_free(new_path);
	}
	if (err != DB_SUCCESS) {
		goto err_exit;
	}

	if (!new_is_tmp) {
		/* Rename all constraints. */
		char	new_table_name[MAX_TABLE_NAME_LEN + 1];
		char	old_table_utf8[MAX_TABLE_NAME_LEN + 1];
		uint	errors = 0;

		strncpy(old_table_utf8, old_name, MAX_TABLE_NAME_LEN);
		old_table_utf8[MAX_TABLE_NAME_LEN] = '\0';
		innobase_convert_to_system_charset(
			strchr(old_table_utf8, '/') + 1,
			strchr(old_name, '/') +1,
			MAX_TABLE_NAME_LEN, &errors);

		if (errors) {
			/* Table name could not be converted from charset
			my_charset_filename to UTF-8. This means that the
			table name is already in UTF-8 (#mysql#50). */
			strncpy(old_table_utf8, old_name, MAX_TABLE_NAME_LEN);
			old_table_utf8[MAX_TABLE_NAME_LEN] = '\0';
		}

		info = pars_info_create();

		pars_info_add_str_literal(info, "new_table_name", new_name);
		pars_info_add_str_literal(info, "old_table_name", old_name);
		pars_info_add_str_literal(info, "old_table_name_utf8",
					  old_table_utf8);

		strncpy(new_table_name, new_name, MAX_TABLE_NAME_LEN);
		new_table_name[MAX_TABLE_NAME_LEN] = '\0';
		innobase_convert_to_system_charset(
			strchr(new_table_name, '/') + 1,
			strchr(new_name, '/') +1,
			MAX_TABLE_NAME_LEN, &errors);

		if (errors) {
			/* Table name could not be converted from charset
			my_charset_filename to UTF-8. This means that the
			table name is already in UTF-8 (#mysql#50). */
			strncpy(new_table_name, new_name, MAX_TABLE_NAME_LEN);
			new_table_name[MAX_TABLE_NAME_LEN] = '\0';
		}

		pars_info_add_str_literal(info, "new_table_utf8", new_table_name);

		err = que_eval_sql(
			info,
			"PROCEDURE RENAME_CONSTRAINT_IDS () IS\n"
			"gen_constr_prefix CHAR;\n"
			"new_db_name CHAR;\n"
			"foreign_id CHAR;\n"
			"new_foreign_id CHAR;\n"
			"old_db_name_len INT;\n"
			"old_t_name_len INT;\n"
			"new_db_name_len INT;\n"
			"id_len INT;\n"
			"offset INT;\n"
			"found INT;\n"
			"BEGIN\n"
			"found := 1;\n"
			"old_db_name_len := INSTR(:old_table_name, '/')-1;\n"
			"new_db_name_len := INSTR(:new_table_name, '/')-1;\n"
			"new_db_name := SUBSTR(:new_table_name, 0,\n"
			"                      new_db_name_len);\n"
			"old_t_name_len := LENGTH(:old_table_name);\n"
			"gen_constr_prefix := CONCAT(:old_table_name_utf8,\n"
			"                            '_ibfk_');\n"
			"WHILE found = 1 LOOP\n"
			"       SELECT ID INTO foreign_id\n"
			"        FROM SYS_FOREIGN\n"
			"        WHERE FOR_NAME = :old_table_name\n"
			"         AND TO_BINARY(FOR_NAME)\n"
			"           = TO_BINARY(:old_table_name)\n"
			"         LOCK IN SHARE MODE;\n"
			"       IF (SQL % NOTFOUND) THEN\n"
			"        found := 0;\n"
			"       ELSE\n"
			"        UPDATE SYS_FOREIGN\n"
			"        SET FOR_NAME = :new_table_name\n"
			"         WHERE ID = foreign_id;\n"
			"        id_len := LENGTH(foreign_id);\n"
			"        IF (INSTR(foreign_id, '/') > 0) THEN\n"
			"               IF (INSTR(foreign_id,\n"
			"                         gen_constr_prefix) > 0)\n"
			"               THEN\n"
                        "                offset := INSTR(foreign_id, '_ibfk_') - 1;\n"
			"                new_foreign_id :=\n"
			"                CONCAT(:new_table_utf8,\n"
			"                SUBSTR(foreign_id, offset,\n"
			"                       id_len - offset));\n"
			"               ELSE\n"
			"                new_foreign_id :=\n"
			"                CONCAT(new_db_name,\n"
			"                SUBSTR(foreign_id,\n"
			"                       old_db_name_len,\n"
			"                       id_len - old_db_name_len));\n"
			"               END IF;\n"
			"               UPDATE SYS_FOREIGN\n"
			"                SET ID = new_foreign_id\n"
			"                WHERE ID = foreign_id;\n"
			"               UPDATE SYS_FOREIGN_COLS\n"
			"                SET ID = new_foreign_id\n"
			"                WHERE ID = foreign_id;\n"
			"        END IF;\n"
			"       END IF;\n"
			"END LOOP;\n"
			"UPDATE SYS_FOREIGN SET REF_NAME = :new_table_name\n"
			"WHERE REF_NAME = :old_table_name\n"
			"  AND TO_BINARY(REF_NAME)\n"
			"    = TO_BINARY(:old_table_name);\n"
			"END;\n"
			, FALSE, trx);

	} else if (n_constraints_to_drop > 0) {
		/* Drop some constraints of tmp tables. */

		ulint	db_name_len = dict_get_db_name_len(old_name) + 1;
		char*	db_name = mem_heap_strdupl(heap, old_name,
						   db_name_len);
		ulint	i;

		for (i = 0; i < n_constraints_to_drop; i++) {
			err = row_delete_constraint(constraints_to_drop[i],
						    db_name, heap, trx);

			if (err != DB_SUCCESS) {
				break;
			}
		}
	}

	if (err == DB_SUCCESS
	    && (dict_table_has_fts_index(table)
	    || DICT_TF2_FLAG_IS_SET(table, DICT_TF2_FTS_HAS_DOC_ID))
	    && !dict_tables_have_same_db(old_name, new_name)) {
		err = fts_rename_aux_tables(table, new_name, trx);
		if (err != DB_TABLE_NOT_FOUND) {
			aux_fts_rename = true;
		}
	}

	if (err != DB_SUCCESS) {
err_exit:
		if (err == DB_DUPLICATE_KEY) {
			ib::error() << "Possible reasons:";
			ib::error() << "(1) Table rename would cause two"
				" FOREIGN KEY constraints to have the same"
				" internal name in case-insensitive"
				" comparison.";
			ib::error() << "(2) Table "
				<< ut_get_name(trx, new_name)
				<< " exists in the InnoDB internal data"
				" dictionary though MySQL is trying to rename"
				" table " << ut_get_name(trx, old_name)
				<< " to it. Have you deleted the .frm file and"
				" not used DROP TABLE?";
			ib::info() << TROUBLESHOOTING_MSG;
			ib::error() << "If table "
				<< ut_get_name(trx, new_name)
				<< " is a temporary table #sql..., then"
				" it can be that there are still queries"
				" running on the table, and it will be dropped"
				" automatically when the queries end. You can"
				" drop the orphaned table inside InnoDB by"
				" creating an InnoDB table with the same name"
				" in another database and copying the .frm file"
				" to the current database. Then MySQL thinks"
				" the table exists, and DROP TABLE will"
				" succeed.";
		}
		trx->error_state = DB_SUCCESS;
		trx->rollback();
		trx->error_state = DB_SUCCESS;
	} else {
		/* The following call will also rename the .ibd data file if
		the table is stored in a single-table tablespace */

		err = dict_table_rename_in_cache(
			table, new_name, !new_is_tmp);
		if (err != DB_SUCCESS) {
			trx->error_state = DB_SUCCESS;
			trx->rollback();
			trx->error_state = DB_SUCCESS;
			goto funct_exit;
		}

		/* In case of copy alter, template db_name and
		table_name should be renamed only for newly
		created table. */
		if (table->vc_templ != NULL && !new_is_tmp) {
			innobase_rename_vc_templ(table);
		}

		/* We only want to switch off some of the type checking in
		an ALTER TABLE, not in a RENAME. */
		dict_names_t	fk_tables;

		err = dict_load_foreigns(
			new_name, NULL, false,
			!old_is_tmp || trx->check_foreigns,
			use_fk
			? DICT_ERR_IGNORE_NONE
			: DICT_ERR_IGNORE_FK_NOKEY,
			fk_tables);

		if (err != DB_SUCCESS) {

			if (old_is_tmp) {
				/* In case of copy alter, ignore the
				loading of foreign key constraint
				when foreign_key_check is disabled */
				ib::error_or_warn(trx->check_foreigns)
					<< "In ALTER TABLE "
					<< ut_get_name(trx, new_name)
					<< " has or is referenced in foreign"
					" key constraints which are not"
					" compatible with the new table"
					" definition.";
				if (!trx->check_foreigns) {
					err = DB_SUCCESS;
					goto funct_exit;
				}
			} else {
				ib::error() << "In RENAME TABLE table "
					<< ut_get_name(trx, new_name)
					<< " is referenced in foreign key"
					" constraints which are not compatible"
					" with the new table definition.";
			}

			trx->error_state = DB_SUCCESS;
			trx->rollback();
			trx->error_state = DB_SUCCESS;
		}

		/* Check whether virtual column or stored column affects
		the foreign key constraint of the table. */
		if (dict_foreigns_has_s_base_col(
				table->foreign_set, table)) {
			err = DB_NO_FK_ON_S_BASE_COL;
			ut_a(DB_SUCCESS == dict_table_rename_in_cache(
				table, old_name, FALSE));
			trx->error_state = DB_SUCCESS;
			trx->rollback();
			trx->error_state = DB_SUCCESS;
			goto funct_exit;
		}

		/* Fill the virtual column set in foreign when
		the table undergoes copy alter operation. */
		dict_mem_table_free_foreign_vcol_set(table);
		dict_mem_table_fill_foreign_vcol_set(table);

		while (!fk_tables.empty()) {
			dict_load_table(fk_tables.front(),
					DICT_ERR_IGNORE_NONE);
			fk_tables.pop_front();
		}

		table->data_dir_path= NULL;
	}

funct_exit:
	if (aux_fts_rename && err != DB_SUCCESS
	    && table != NULL && (table->space != 0)) {

		char*	orig_name = table->name.m_name;
		trx_t*	trx_bg = trx_create();

		/* If the first fts_rename fails, the trx would
		be rolled back and committed, we can't use it any more,
		so we have to start a new background trx here. */
		ut_a(trx_state_eq(trx_bg, TRX_STATE_NOT_STARTED));
		trx_bg->op_info = "Revert the failing rename "
				  "for fts aux tables";
		trx_bg->dict_operation_lock_mode = RW_X_LATCH;
		trx_start_for_ddl(trx_bg, TRX_DICT_OP_TABLE);

		/* If rename fails and table has its own tablespace,
		we need to call fts_rename_aux_tables again to
		revert the ibd file rename, which is not under the
		control of trx. Also notice the parent table name
		in cache is not changed yet. If the reverting fails,
		the ibd data may be left in the new database, which
		can be fixed only manually. */
		table->name.m_name = const_cast<char*>(new_name);
		fts_rename_aux_tables(table, old_name, trx_bg);
		table->name.m_name = orig_name;

		trx_bg->dict_operation_lock_mode = 0;
		trx_commit_for_mysql(trx_bg);
		trx_bg->free();
	}

	if (table != NULL) {
		if (commit && !table->is_temporary()) {
			table->stats_bg_flag &= byte(~BG_STAT_SHOULD_QUIT);
		}
		dict_table_close(table, dict_locked, FALSE);
	}

	if (commit) {
		DEBUG_SYNC(trx->mysql_thd, "before_rename_table_commit");
		trx_commit_for_mysql(trx);
	}

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}

	trx->op_info = "";

	return(err);
}

/*********************************************************************//**
Scans an index for either COUNT(*) or CHECK TABLE.
If CHECK TABLE; Checks that the index contains entries in an ascending order,
unique constraint is not broken, and calculates the number of index entries
in the read view of the current transaction.
@return DB_SUCCESS or other error */
dberr_t
row_scan_index_for_mysql(
/*=====================*/
	row_prebuilt_t*		prebuilt,	/*!< in: prebuilt struct
						in MySQL handle */
	const dict_index_t*	index,		/*!< in: index */
	ulint*			n_rows)		/*!< out: number of entries
						seen in the consistent read */
{
	dtuple_t*	prev_entry	= NULL;
	ulint		matched_fields;
	byte*		buf;
	dberr_t		ret;
	rec_t*		rec;
	int		cmp;
	ibool		contains_null;
	ulint		i;
	ulint		cnt;
	mem_heap_t*	heap		= NULL;
	rec_offs	offsets_[REC_OFFS_NORMAL_SIZE];
	rec_offs*	offsets;
	rec_offs_init(offsets_);

	*n_rows = 0;

	/* Don't support RTree Leaf level scan */
	ut_ad(!dict_index_is_spatial(index));

	if (dict_index_is_clust(index)) {
		/* The clustered index of a table is always available.
		During online ALTER TABLE that rebuilds the table, the
		clustered index in the old table will have
		index->online_log pointing to the new table. All
		indexes of the old table will remain valid and the new
		table will be unaccessible to MySQL until the
		completion of the ALTER TABLE. */
	} else if (dict_index_is_online_ddl(index)
		   || (index->type & DICT_FTS)) {
		/* Full Text index are implemented by auxiliary tables,
		not the B-tree. We also skip secondary indexes that are
		being created online. */
		return(DB_SUCCESS);
	}

	ulint bufsize = std::max<ulint>(srv_page_size,
					prebuilt->mysql_row_len);
	buf = static_cast<byte*>(ut_malloc_nokey(bufsize));
	heap = mem_heap_create(100);

	cnt = 1000;

	ret = row_search_for_mysql(buf, PAGE_CUR_G, prebuilt, 0, 0);
loop:
	/* Check thd->killed every 1,000 scanned rows */
	if (--cnt == 0) {
		if (trx_is_interrupted(prebuilt->trx)) {
			ret = DB_INTERRUPTED;
			goto func_exit;
		}
		cnt = 1000;
	}

	switch (ret) {
	case DB_SUCCESS:
		break;
	case DB_DEADLOCK:
	case DB_LOCK_TABLE_FULL:
	case DB_LOCK_WAIT_TIMEOUT:
	case DB_INTERRUPTED:
		goto func_exit;
	default:
		ib::warn() << "CHECK TABLE on index " << index->name << " of"
			" table " << index->table->name << " returned " << ret;
		/* (this error is ignored by CHECK TABLE) */
		/* fall through */
	case DB_END_OF_INDEX:
		ret = DB_SUCCESS;
func_exit:
		ut_free(buf);
		mem_heap_free(heap);

		return(ret);
	}

	*n_rows = *n_rows + 1;

	/* else this code is doing handler::check() for CHECK TABLE */

	/* row_search... returns the index record in buf, record origin offset
	within buf stored in the first 4 bytes, because we have built a dummy
	template */

	rec = buf + mach_read_from_4(buf);

	offsets = rec_get_offsets(rec, index, offsets_, index->n_core_fields,
				  ULINT_UNDEFINED, &heap);

	if (prev_entry != NULL) {
		matched_fields = 0;

		cmp = cmp_dtuple_rec_with_match(prev_entry, rec, offsets,
						&matched_fields);
		contains_null = FALSE;

		/* In a unique secondary index we allow equal key values if
		they contain SQL NULLs */

		for (i = 0;
		     i < dict_index_get_n_ordering_defined_by_user(index);
		     i++) {
			if (UNIV_SQL_NULL == dfield_get_len(
				    dtuple_get_nth_field(prev_entry, i))) {

				contains_null = TRUE;
				break;
			}
		}

		const char* msg;

		if (cmp > 0) {
			ret = DB_INDEX_CORRUPT;
			msg = "index records in a wrong order in ";
not_ok:
			ib::error()
				<< msg << index->name
				<< " of table " << index->table->name
				<< ": " << *prev_entry << ", "
				<< rec_offsets_print(rec, offsets);
			/* Continue reading */
		} else if (dict_index_is_unique(index)
			   && !contains_null
			   && matched_fields
			   >= dict_index_get_n_ordering_defined_by_user(
				   index)) {
			ret = DB_DUPLICATE_KEY;
			msg = "duplicate key in ";
			goto not_ok;
		}
	}

	{
		mem_heap_t*	tmp_heap = NULL;

		/* Empty the heap on each round.  But preserve offsets[]
		for the row_rec_to_index_entry() call, by copying them
		into a separate memory heap when needed. */
		if (UNIV_UNLIKELY(offsets != offsets_)) {
			ulint	size = rec_offs_get_n_alloc(offsets)
				* sizeof *offsets;

			tmp_heap = mem_heap_create(size);

			offsets = static_cast<rec_offs*>(
				mem_heap_dup(tmp_heap, offsets, size));
		}

		mem_heap_empty(heap);

		prev_entry = row_rec_to_index_entry(
			rec, index, offsets, heap);

		if (UNIV_LIKELY_NULL(tmp_heap)) {
			mem_heap_free(tmp_heap);
		}
	}

	ret = row_search_for_mysql(
		buf, PAGE_CUR_G, prebuilt, 0, ROW_SEL_NEXT);

	goto loop;
}

/*********************************************************************//**
Initialize this module */
void
row_mysql_init(void)
/*================*/
{
	mutex_create(LATCH_ID_ROW_DROP_LIST, &row_drop_list_mutex);

	UT_LIST_INIT(
		row_mysql_drop_list,
		&row_mysql_drop_t::row_mysql_drop_list);

	row_mysql_drop_list_inited = true;
}

void row_mysql_close()
{
  ut_ad(!UT_LIST_GET_LEN(row_mysql_drop_list) ||
        srv_force_recovery >= SRV_FORCE_NO_BACKGROUND);
  if (row_mysql_drop_list_inited)
  {
    row_mysql_drop_list_inited= false;
    mutex_free(&row_drop_list_mutex);

    while (row_mysql_drop_t *drop= UT_LIST_GET_FIRST(row_mysql_drop_list))
    {
      UT_LIST_REMOVE(row_mysql_drop_list, drop);
      ut_free(drop);
    }
  }
}