~drizzle-trunk/drizzle/development

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

Copyright (c) 2000, 2009, Innobase Oy. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under

the terms of the GNU General Public License as published by the Free Software

Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT

ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with

this program; if not, write to the Free Software Foundation, Inc., 59 Temple

Place, Suite 330, Boston, MA 02111-1307 USA

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

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

Interface between Innobase row operations and MySQL.

Contains also create table and other data dictionary operations.

Created 9/17/2000 Heikki Tuuri

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

#ifndef row0mysql_h

#define row0mysql_h

#include "univ.i"

#include "data0data.h"

#include "que0types.h"

#include "dict0types.h"

#include "trx0types.h"

#include "row0types.h"

#include "btr0pcur.h"

#include "trx0types.h"

extern ibool row_rollback_on_timeout;

typedef struct row_prebuilt_struct row_prebuilt_t;

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

Frees the blob heap in prebuilt when no longer needed. */

UNIV_INTERN

void

row_mysql_prebuilt_free_blob_heap(

/*==============================*/

	row_prebuilt_t*	prebuilt);	/* in: prebuilt struct of a

					ha_innobase:: table handle */

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

Stores a >= 5.0.3 format true VARCHAR length to dest, in the MySQL row

format. */

UNIV_INTERN

byte*

row_mysql_store_true_var_len(

/*=========================*/

			/* out: pointer to the data, we skip the 1 or 2 bytes

			at the start that are used to store the 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 */

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

Reads a >= 5.0.3 format true VARCHAR length, in the MySQL row format, and

returns a pointer to the data. */

const byte*

row_mysql_read_true_varchar(

/*========================*/

				/* out: pointer to the data, we skip

				the 1 or 2 bytes at the start that are

				used to store the len */

	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 */

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

Stores a reference to a BLOB in the MySQL format. */

UNIV_INTERN

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! */

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

Reads a reference to a BLOB in the MySQL format. */

const byte*

row_mysql_read_blob_ref(

/*====================*/

					/* out: pointer to BLOB data */

	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) */

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

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.c. */

UNIV_INTERN

byte*

row_mysql_store_col_in_innobase_format(

/*===================================*/

					/* out: up to which byte we used

					buf in the conversion */

	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! */

	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 */

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

Handles user errors and lock waits detected by the database engine. */

UNIV_INTERN

ibool

row_mysql_handle_errors(

/*====================*/

				/* out: TRUE if it was a lock wait and

				we should continue running the query thread */

	ulint*		new_err,/* out: possible new error encountered in

				rollback, or the old error which was

				during the function entry */

	trx_t*		trx,	/* in: transaction */

	que_thr_t*	thr,	/* in: query thread */

	trx_savept_t*	savept);/* in: savepoint */

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

Create a prebuilt struct for a MySQL table handle. */

UNIV_INTERN

row_prebuilt_t*

row_create_prebuilt(

/*================*/

				/* out, own: a prebuilt struct */

	dict_table_t*	table);	/* in: Innobase table handle */

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

Free a prebuilt struct for a MySQL table handle. */

UNIV_INTERN

void

row_prebuilt_free(

/*==============*/

	row_prebuilt_t*	prebuilt,	/* in, own: prebuilt struct */

	ibool		dict_locked);	/* in: TRUE=data dictionary locked */

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

Updates the transaction pointers in query graphs stored in the prebuilt

struct. */

UNIV_INTERN

void

row_update_prebuilt_trx(

/*====================*/

					/* out: prebuilt dtuple */

	row_prebuilt_t*	prebuilt,	/* in: prebuilt struct in MySQL

					handle */

	trx_t*		trx);		/* in: transaction handle */

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

Unlocks AUTO_INC type locks that were possibly reserved by a trx. */

UNIV_INTERN

void

row_unlock_table_autoinc_for_mysql(

/*===============================*/

	trx_t*	trx);			/* in/out: transaction */

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

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. */

UNIV_INTERN

int

row_lock_table_autoinc_for_mysql(

/*=============================*/

					/* out: error code or DB_SUCCESS */

	row_prebuilt_t*	prebuilt);	/* in: prebuilt struct in the MySQL

					table handle */

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

Sets a table lock on the table mentioned in prebuilt. */

UNIV_INTERN

int

row_lock_table_for_mysql(

/*=====================*/

					/* out: error code or DB_SUCCESS */

	row_prebuilt_t*	prebuilt,	/* in: prebuilt struct in the MySQL

					table handle */

	dict_table_t*	table,		/* in: table to lock, or NULL

					if prebuilt->table should be

					locked as

					prebuilt->select_lock_type */

	ulint		mode);		/* in: lock mode of table

					(ignored if table==NULL) */

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

Does an insert for MySQL. */

UNIV_INTERN

int

row_insert_for_mysql(

/*=================*/

					/* out: error code or DB_SUCCESS */

	byte*		mysql_rec,	/* in: row in the MySQL format */

	row_prebuilt_t*	prebuilt);	/* in: prebuilt struct in MySQL

					handle */

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

Builds a dummy query graph used in selects. */

UNIV_INTERN

void

row_prebuild_sel_graph(

/*===================*/

	row_prebuilt_t*	prebuilt);	/* in: prebuilt struct in MySQL

					handle */

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

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. */

UNIV_INTERN

upd_t*

row_get_prebuilt_update_vector(

/*===========================*/

					/* out: prebuilt update vector */

	row_prebuilt_t*	prebuilt);	/* in: prebuilt struct in MySQL

					handle */

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

Checks if a table is such that we automatically created a clustered

index on it (on row id). */

UNIV_INTERN

ibool

row_table_got_default_clust_index(

/*==============================*/

	const dict_table_t*	table);

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

Calculates the key number used inside MySQL for an Innobase index. We have

to take into account if we generated a default clustered index for the table */

UNIV_INTERN

ulint

row_get_mysql_key_number_for_index(

/*===============================*/

	const dict_index_t*	index);

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

Does an update or delete of a row for MySQL. */

UNIV_INTERN

int

row_update_for_mysql(

/*=================*/

					/* out: error code or DB_SUCCESS */

	byte*		mysql_rec,	/* in: the row to be updated, in

					the MySQL format */

	row_prebuilt_t*	prebuilt);	/* in: prebuilt struct in MySQL

					handle */

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

This can only be used when srv_locks_unsafe_for_binlog is TRUE or

session is using a READ COMMITTED isolation level. Before

calling this function we must use trx_reset_new_rec_lock_info() and

trx_register_new_rec_lock() to store the information which new record locks

really were set. This function removes a newly set lock under prebuilt->pcur,

and also under prebuilt->clust_pcur. Currently, this is only used and tested

in the case of an UPDATE or a DELETE statement, where the row lock is of the

LOCK_X type.

Thus, this implements a 'mini-rollback' that releases the latest record

locks we set. */

UNIV_INTERN

int

row_unlock_for_mysql(

/*=================*/

					/* out: error code or DB_SUCCESS */

	row_prebuilt_t*	prebuilt,	/* in: prebuilt struct in MySQL

					handle */

	ibool		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. */

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

Creates an query graph node of 'update' type to be used in the MySQL

interface. */

UNIV_INTERN

upd_node_t*

row_create_update_node_for_mysql(

/*=============================*/

				/* out, own: update node */

	dict_table_t*	table,	/* in: table to update */

	mem_heap_t*	heap);	/* in: mem heap from which allocated */

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

Does a cascaded delete or set null in a foreign key operation. */

UNIV_INTERN

ulint

row_update_cascade_for_mysql(

/*=========================*/

				/* out: error code or DB_SUCCESS */

	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 */

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

Locks the data dictionary exclusively for performing a table create or other

data dictionary modification operation. */

UNIV_INTERN

void

row_mysql_lock_data_dictionary_func(

/*================================*/

	trx_t*		trx,	/* in/out: transaction */

	const char*	file,	/* in: file name */

	ulint		line);	/* in: line number */

#define row_mysql_lock_data_dictionary(trx)				\

	row_mysql_lock_data_dictionary_func(trx, __FILE__, __LINE__)

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

Unlocks the data dictionary exclusive lock. */

UNIV_INTERN

void

row_mysql_unlock_data_dictionary(

/*=============================*/

	trx_t*	trx);	/* in/out: transaction */

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

Locks the data dictionary in shared mode from modifications, for performing

foreign key check, rollback, or other operation invisible to MySQL. */

UNIV_INTERN

void

row_mysql_freeze_data_dictionary_func(

/*==================================*/

	trx_t*		trx,	/* in/out: transaction */

	const char*	file,	/* in: file name */

	ulint		line);	/* in: line number */

#define row_mysql_freeze_data_dictionary(trx)				\

	row_mysql_freeze_data_dictionary_func(trx, __FILE__, __LINE__)

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

Unlocks the data dictionary shared lock. */

UNIV_INTERN

void

row_mysql_unfreeze_data_dictionary(

/*===============================*/

	trx_t*	trx);	/* in/out: transaction */

#ifndef UNIV_HOTBACKUP

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

Creates a table for MySQL. If the name of the table ends in

one of "innodb_monitor", "innodb_lock_monitor", "innodb_tablespace_monitor",

"innodb_table_monitor", then this will also start the printing of monitor

output by the master thread. If the table name ends in "innodb_mem_validate",

InnoDB will try to invoke mem_validate(). */

UNIV_INTERN

int

row_create_table_for_mysql(

/*=======================*/

					/* out: error code or DB_SUCCESS */

	dict_table_t*	table,		/* in, own: table definition

					(will be freed) */

	trx_t*		trx);		/* in: transaction handle */

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

Does an index creation operation for MySQL. TODO: currently failure

to create an index results in dropping the whole table! This is no problem

currently as all indexes must be created at the same time as the table. */

UNIV_INTERN

int

row_create_index_for_mysql(

/*=======================*/

					/* out: error number or DB_SUCCESS */

	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. */

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

Scans a table create SQL string and adds to the data dictionary

the foreign key constraints declared in the string. This function

should be called after the indexes for a table have been created.

Each foreign key constraint must be accompanied with indexes in

bot participating tables. The indexes are allowed to contain more

fields than mentioned in the constraint. */

UNIV_INTERN

int

row_table_add_foreign_constraints(

/*==============================*/

					/* out: error code or DB_SUCCESS */

	trx_t*		trx,		/* in: transaction */

	const char*	sql_string,	/* in: table create statement where

					foreign keys are declared like:

				FOREIGN KEY (a, b) REFERENCES table2(c, d),

					table2 can be written also with the

					database name before it: test.table2 */

	const char*	name,		/* in: table full name in the

					normalized form

					database_name/table_name */

	ibool		reject_fks);	/* in: if TRUE, fail with error

					code DB_CANNOT_ADD_CONSTRAINT if

					any foreign keys are found. */

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

The master thread in srv0srv.c 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. */

UNIV_INTERN

ulint

row_drop_tables_for_mysql_in_background(void);

/*=========================================*/

					/* out: how many tables dropped

					+ remaining tables in list */

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

Get the background drop list length. NOTE: the caller must own the kernel

mutex! */

UNIV_INTERN

ulint

row_get_background_drop_list_len_low(void);

/*======================================*/

					/* out: how many tables in list */

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

Truncates a table for MySQL. */

UNIV_INTERN

int

row_truncate_table_for_mysql(

/*=========================*/

				/* out: error code or DB_SUCCESS */

	dict_table_t*	table,	/* in: table handle */

	trx_t*		trx);	/* in: transaction handle */

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

Drops a table for MySQL.  If the name of the dropped table ends in

one of "innodb_monitor", "innodb_lock_monitor", "innodb_tablespace_monitor",

"innodb_table_monitor", then this will also stop the printing of monitor

output by the master thread.  If the data dictionary was not already locked

by the transaction, the transaction will be committed.  Otherwise, the

data dictionary will remain locked. */

UNIV_INTERN

int

row_drop_table_for_mysql(

/*=====================*/

				/* out: error code or DB_SUCCESS */

	const char*	name,	/* in: table name */

	trx_t*		trx,	/* in: transaction handle */

	ibool		drop_db);/* in: TRUE=dropping whole database */

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

Discards the tablespace of a table which stored in an .ibd file. Discarding

means that this function deletes the .ibd file and assigns a new table id for

the table. Also the flag table->ibd_file_missing is set TRUE. */

UNIV_INTERN

int

row_discard_tablespace_for_mysql(

/*=============================*/

				/* out: error code or DB_SUCCESS */

	const char*	name,	/* in: table name */

	trx_t*		trx);	/* in: transaction handle */

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

Imports a tablespace. The space id in the .ibd file must match the space id

of the table in the data dictionary. */

UNIV_INTERN

int

row_import_tablespace_for_mysql(

/*============================*/

				/* out: error code or DB_SUCCESS */

	const char*	name,	/* in: table name */

	trx_t*		trx);	/* in: transaction handle */

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

Drops a database for MySQL. */

UNIV_INTERN

int

row_drop_database_for_mysql(

/*========================*/

				/* out: error code or DB_SUCCESS */

	const char*	name,	/* in: database name which ends to '/' */

	trx_t*		trx);	/* in: transaction handle */

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

Renames a table for MySQL. */

UNIV_INTERN

ulint

row_rename_table_for_mysql(

/*=======================*/

					/* out: error code or DB_SUCCESS */

	const char*	old_name,	/* in: old table name */

	const char*	new_name,	/* in: new table name */

	trx_t*		trx,		/* in: transaction handle */

	ibool		commit);	/* in: if TRUE then commit trx */

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

Checks a table for corruption. */

UNIV_INTERN

ulint

row_check_table_for_mysql(

/*======================*/

					/* out: DB_ERROR or DB_SUCCESS */

	row_prebuilt_t*	prebuilt);	/* in: prebuilt struct in MySQL

					handle */

#endif /* !UNIV_HOTBACKUP */

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

Determines if a table is a magic monitor table. */

UNIV_INTERN

ibool

row_is_magic_monitor_table(

/*=======================*/

					/* out: TRUE if monitor table */

	const char*	table_name);	/* in: name of the table, in the

					form database/table_name */

/* A struct describing a place for an individual column in the MySQL

row format which is presented to the table handler in ha_innobase.

This template struct is used to speed up row transformations between

Innobase and MySQL. */

typedef struct mysql_row_templ_struct mysql_row_templ_t;

struct mysql_row_templ_struct {

	ulint	col_no;			/* column number of the column */

	ulint	rec_field_no;		/* field number of the column in an

					Innobase record in the current index;

					not defined if template_type is

					ROW_MYSQL_WHOLE_ROW */

	ulint	mysql_col_offset;	/* offset of the column in the MySQL

					row format */

	ulint	mysql_col_len;		/* length of the column in the MySQL

					row format */

	ulint	mysql_null_byte_offset;	/* MySQL NULL bit byte offset in a

					MySQL record */

	ulint	mysql_null_bit_mask;	/* bit mask to get the NULL bit,

					zero if column cannot be NULL */

	ulint	type;			/* column type in Innobase mtype

					numbers DATA_CHAR... */

	ulint	mysql_type;		/* MySQL type code; this is always

					< 256 */

	ulint	mysql_length_bytes;	/* if mysql_type

					== DATA_MYSQL_TRUE_VARCHAR, this tells

					whether we should use 1 or 2 bytes to

					store the MySQL true VARCHAR data

					length at the start of row in the MySQL

					format (NOTE that the MySQL key value

					format always uses 2 bytes for the data

					len) */

	ulint	charset;		/* MySQL charset-collation code

					of the column, or zero */

	ulint	mbminlen;		/* minimum length of a char, in bytes,

					or zero if not a char type */

	ulint	mbmaxlen;		/* maximum length of a char, in bytes,

					or zero if not a char type */

	ulint	is_unsigned;		/* if a column type is an integer

					type and this field is != 0, then

					it is an unsigned integer type */

};

#define MYSQL_FETCH_CACHE_SIZE		8

/* After fetching this many rows, we start caching them in fetch_cache */

#define MYSQL_FETCH_CACHE_THRESHOLD	4

#define ROW_PREBUILT_ALLOCATED	78540783

#define ROW_PREBUILT_FREED	26423527

typedef int64_t (*index_cond_func_t)(void *param);

/* A struct for (sometimes lazily) prebuilt structures in an Innobase table

handle used within MySQL; these are used to save CPU time. */

struct row_prebuilt_struct {

	ulint		magic_n;	/* this magic number is set to

					ROW_PREBUILT_ALLOCATED when created,

					or ROW_PREBUILT_FREED when the

					struct has been freed */

	dict_table_t*	table;		/* Innobase table handle */

	trx_t*		trx;		/* current transaction handle */

	ibool		sql_stat_start;	/* TRUE when we start processing of

					an SQL statement: we may have to set

					an intention lock on the table,

					create a consistent read view etc. */

	ibool		mysql_has_locked; /* this is set TRUE when MySQL

					calls external_lock on this handle

					with a lock flag, and set FALSE when

					with the F_UNLOCK flag */

	ibool		clust_index_was_generated;

					/* if the user did not define a

					primary key in MySQL, then Innobase

					automatically generated a clustered

					index where the ordering column is

					the row id: in this case this flag

					is set to TRUE */

	dict_index_t*	index;		/* current index for a search, if

					any */

	ulint		read_just_key;	/* set to 1 when MySQL calls

					ha_innobase::extra with the

					argument HA_EXTRA_KEYREAD; it is enough

					to read just columns defined in

					the index (i.e., no read of the

					clustered index record necessary) */

	ibool		used_in_HANDLER;/* TRUE if we have been using this

					handle in a MySQL HANDLER low level

					index cursor command: then we must

					store the pcur position even in a

					unique search from a clustered index,

					because HANDLER allows NEXT and PREV

					in such a situation */

	ulint		template_type;	/* ROW_MYSQL_WHOLE_ROW,

					ROW_MYSQL_REC_FIELDS,

					ROW_MYSQL_DUMMY_TEMPLATE, or

					ROW_MYSQL_NO_TEMPLATE */

	ulint		n_template;	/* number of elements in the

					template */

	ulint		null_bitmap_len;/* number of bytes in the SQL NULL

					bitmap at the start of a row in the

					MySQL format */

	ibool		need_to_access_clustered; /* if we are fetching

					columns through a secondary index

					and at least one column is not in

					the secondary index, then this is

					set to TRUE */

	ibool		templ_contains_blob;/* TRUE if the template contains

					BLOB column(s) */

	mysql_row_templ_t* mysql_template;/* template used to transform

					rows fast between MySQL and Innobase

					formats; memory for this template

					is not allocated from 'heap' */

	mem_heap_t*	heap;		/* memory heap from which

					these auxiliary structures are

					allocated when needed */

	ins_node_t*	ins_node;	/* Innobase SQL insert node

					used to perform inserts

					to the table */

	byte*		ins_upd_rec_buff;/* buffer for storing data converted

					to the Innobase format from the MySQL

					format */

	const byte*	default_rec;	/* the default values of all columns

					(a "default row") in MySQL format */

	ulint		hint_need_to_fetch_extra_cols;

					/* normally this is set to 0; if this

					is set to ROW_RETRIEVE_PRIMARY_KEY,

					then we should at least retrieve all

					columns in the primary key; if this

					is set to ROW_RETRIEVE_ALL_COLS, then

					we must retrieve all columns in the

					key (if read_just_key == 1), or all

					columns in the table */

	upd_node_t*	upd_node;	/* Innobase SQL update node used

					to perform updates and deletes */

	que_fork_t*	ins_graph;	/* Innobase SQL query graph used

					in inserts */

	que_fork_t*	upd_graph;	/* Innobase SQL query graph used

					in updates or deletes */

	btr_pcur_t*	pcur;		/* persistent cursor used in selects

					and updates */

	btr_pcur_t*	clust_pcur;	/* persistent cursor used in

					some selects and updates */

	que_fork_t*	sel_graph;	/* dummy query graph used in

					selects */

	dtuple_t*	search_tuple;	/* prebuilt dtuple used in selects */

	byte		row_id[DATA_ROW_ID_LEN];

					/* if the clustered index was

					generated, the row id of the

					last row fetched is stored

					here */

	dtuple_t*	clust_ref;	/* prebuilt dtuple used in

					sel/upd/del */

	ulint		select_lock_type;/* LOCK_NONE, LOCK_S, or LOCK_X */

	ulint		stored_select_lock_type;/* this field is used to

					remember the original select_lock_type

					that was decided in ha_innodb.cc,

					::store_lock(), ::external_lock(),

					etc. */

	ulint		row_read_type;	/* ROW_READ_WITH_LOCKS if row locks

					should be the obtained for records

					under an UPDATE or DELETE cursor.

					If innodb_locks_unsafe_for_binlog

					is TRUE, this can be set to

					ROW_READ_TRY_SEMI_CONSISTENT, so that

					if the row under an UPDATE or DELETE

					cursor was locked by another

					transaction, InnoDB will resort

					to reading the last committed value

					('semi-consistent read').  Then,

					this field will be set to

					ROW_READ_DID_SEMI_CONSISTENT to

					indicate that.	If the row does not

					match the WHERE condition, MySQL will

					invoke handler::unlock_row() to

					clear the flag back to

					ROW_READ_TRY_SEMI_CONSISTENT and

					to simply skip the row.	 If

					the row matches, the next call to

					row_search_for_mysql() will lock

					the row.

					This eliminates lock waits in some

					cases; note that this breaks

					serializability. */

	ulint		mysql_prefix_len;/* byte offset of the end of

					the last requested column */

	ulint		mysql_row_len;	/* length in bytes of a row in the

					MySQL format */

	ulint		n_rows_fetched;	/* number of rows fetched after

					positioning the current cursor */

	ulint		fetch_direction;/* ROW_SEL_NEXT or ROW_SEL_PREV */

	byte*		fetch_cache[MYSQL_FETCH_CACHE_SIZE];

					/* a cache for fetched rows if we

					fetch many rows from the same cursor:

					it saves CPU time to fetch them in a

					batch; we reserve mysql_row_len

					bytes for each such row; these

					pointers point 4 bytes past the

					allocated mem buf start, because

					there is a 4 byte magic number at the

					start and at the end */

	ibool		keep_other_fields_on_keyread; /* when using fetch

					cache with HA_EXTRA_KEYREAD, don't

					overwrite other fields in mysql row

					row buffer.*/

	ulint		fetch_cache_first;/* position of the first not yet

					fetched row in fetch_cache */

	ulint		n_fetch_cached;	/* number of not yet fetched rows

					in fetch_cache */

	mem_heap_t*	blob_heap;	/* in SELECTS BLOB fields are copied

					to this heap */

	mem_heap_t*	old_vers_heap;	/* memory heap where a previous

					version is built in consistent read */

	/*----------------------*/

	ib_uint64_t	autoinc_last_value;/* last value of AUTO-INC interval */

	ib_uint64_t	autoinc_increment;/* The increment step of the auto 

					increment column. Value must be

					greater than or equal to 1. Required to

					calculate the next value */

	ib_uint64_t	autoinc_offset; /* The offset passed to

					get_auto_increment() by MySQL. Required

					to calculate the next value */

	ulint		autoinc_error;	/* The actual error code encountered

					while trying to init or read the

					autoinc value from the table. We

					store it here so that we can return

					it to MySQL */

	/*----------------------*/

	UT_LIST_NODE_T(row_prebuilt_t)	prebuilts;

					/* list node of table->prebuilts */

	index_cond_func_t idx_cond_func;/* Index Condition Pushdown function,

                                        or NULL if there is none set */

	void*           idx_cond_func_arg;/* ICP function  argument */

        ulint           n_index_fields; /* Number of fields at the start of

                                        mysql_template. Valid only when using

                                        ICP. */

	ulint		magic_n2;	/* this should be the same as

					magic_n */

};

#define ROW_PREBUILT_FETCH_MAGIC_N	465765687

#define ROW_MYSQL_WHOLE_ROW	0

#define ROW_MYSQL_REC_FIELDS	1

#define ROW_MYSQL_NO_TEMPLATE	2

#define ROW_MYSQL_DUMMY_TEMPLATE 3	/* dummy template used in

					row_scan_and_check_index */

/* Values for hint_need_to_fetch_extra_cols */

#define ROW_RETRIEVE_PRIMARY_KEY	1

#define ROW_RETRIEVE_ALL_COLS		2

/* Values for row_read_type */

#define ROW_READ_WITH_LOCKS		0

#define ROW_READ_TRY_SEMI_CONSISTENT	1

#define ROW_READ_DID_SEMI_CONSISTENT	2

#ifndef UNIV_NONINL

#include "row0mysql.ic"

#endif

#endif