table.h

#ifndef TABLE_INCLUDED
#define TABLE_INCLUDED

/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include "my_global.h"                          /* NO_EMBEDDED_ACCESS_CHECKS */
#include "sql_plist.h"
#include "sql_alloc.h"
#include "mdl.h"
#include "datadict.h"

#ifndef MYSQL_CLIENT

#include "hash.h"                               /* HASH */
#include "handler.h"                /* row_type, ha_choice, handler */
#include "mysql_com.h"              /* enum_field_types */
#include "thr_lock.h"                  /* thr_lock_type */
#include "filesort_utils.h"
#include "parse_file.h"
#include "table_id.h"

/* Structs that defines the TABLE */

class Item;                             /* Needed by ORDER */
class Item_subselect;
class Item_field;
class GRANT_TABLE;
class st_select_lex_unit;
class st_select_lex;
class partition_info;
class COND_EQUAL;
class Security_context;
struct TABLE_LIST;
class ACL_internal_schema_access;
class ACL_internal_table_access;
class Field;
class Field_temporal_with_date_and_time;
class Table_cache_element;

/*
  Used to identify NESTED_JOIN structures within a join (applicable to
  structures representing outer joins that have not been simplified away).
*/
typedef ulonglong nested_join_map;


#define tmp_file_prefix "#sql"                  
#define tmp_file_prefix_length 4
#define TMP_TABLE_KEY_EXTRA 8

enum enum_table_ref_type
{
  TABLE_REF_NULL= 0,
  TABLE_REF_VIEW,
  TABLE_REF_BASE_TABLE,
  TABLE_REF_I_S_TABLE,
  TABLE_REF_TMP_TABLE
};

enum enum_ident_name_check
{
  IDENT_NAME_OK,
  IDENT_NAME_WRONG,
  IDENT_NAME_TOO_LONG
};

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

class Object_creation_ctx
{
public:
  Object_creation_ctx *set_n_backup(THD *thd);

  void restore_env(THD *thd, Object_creation_ctx *backup_ctx);

protected:
  Object_creation_ctx() {}
  virtual Object_creation_ctx *create_backup_ctx(THD *thd) const = 0;

  virtual void change_env(THD *thd) const = 0;

public:
  virtual ~Object_creation_ctx()
  { }
};

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

class Default_object_creation_ctx : public Object_creation_ctx
{
public:
  const CHARSET_INFO *get_client_cs()
  {
    return m_client_cs;
  }

  const CHARSET_INFO *get_connection_cl()
  {
    return m_connection_cl;
  }

protected:
  Default_object_creation_ctx(THD *thd);

  Default_object_creation_ctx(const CHARSET_INFO *client_cs,
                              const CHARSET_INFO *connection_cl);

protected:
  virtual Object_creation_ctx *create_backup_ctx(THD *thd) const;

  virtual void change_env(THD *thd) const;

protected:
  const CHARSET_INFO *m_client_cs;

  const CHARSET_INFO *m_connection_cl;
};


class View_creation_ctx : public Default_object_creation_ctx,
                          public Sql_alloc
{
public:
  static View_creation_ctx *create(THD *thd);

  static View_creation_ctx *create(THD *thd,
                                   TABLE_LIST *view);

private:
  View_creation_ctx(THD *thd)
    : Default_object_creation_ctx(thd)
  { }
};

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

typedef struct st_order {
  struct st_order *next;
  Item   **item;                        /* Point at item in select fields */
  Item   *item_ptr;                     /* Storage for initial item */
  int    counter;                       /* position in SELECT list, correct
                                           only if counter_used is true */
  enum enum_order {
    ORDER_NOT_RELEVANT,
    ORDER_ASC,
    ORDER_DESC
  };

  enum_order direction;                 /* Requested direction of ordering */
  bool   in_field_list;                 /* true if in select field list */
  bool   counter_used;                  /* parameter was counter of columns */
  bool   used_alias;
  Field  *field;                        /* If tmp-table group */
  char   *buff;                         /* If tmp-table group */
  table_map used, depend_map;
} ORDER;

struct st_grant_internal_info
{
  bool m_schema_lookup_done;
  const ACL_internal_schema_access *m_schema_access;
  bool m_table_lookup_done;
  const ACL_internal_table_access *m_table_access;
};
typedef struct st_grant_internal_info GRANT_INTERNAL_INFO;

typedef struct st_grant_info
{
  GRANT_TABLE *grant_table;
  uint version;
  ulong privilege;
  ulong want_privilege;
  ulong orig_want_privilege;
  GRANT_INTERNAL_INFO m_internal;
} GRANT_INFO;

enum tmp_table_type
{
  NO_TMP_TABLE, NON_TRANSACTIONAL_TMP_TABLE, TRANSACTIONAL_TMP_TABLE,
  INTERNAL_TMP_TABLE, SYSTEM_TMP_TABLE
};
enum release_type { RELEASE_NORMAL, RELEASE_WAIT_FOR_DROP };


class Filesort_info
{
  Filesort_buffer filesort_buffer;

public:
  IO_CACHE *io_cache;           /* If sorted through filesort */
  uchar     *buffpek;           /* Buffer for buffpek structures */
  uint      buffpek_len;        /* Max number of buffpeks in the buffer */
  uchar     *addon_buf;         /* Pointer to a buffer if sorted with fields */
  size_t    addon_length;       /* Length of the buffer */
  struct st_sort_addon_field *addon_field;     /* Pointer to the fields info */
  void    (*unpack)(struct st_sort_addon_field *, uchar *); /* To unpack back */
  uchar     *record_pointers;    /* If sorted in memory */
  ha_rows   found_records;      /* How many records in sort */

  Filesort_info(): record_pointers(0) {};
  void sort_buffer(Sort_param *param, uint count)
  { filesort_buffer.sort_buffer(param, count); }

  uchar *get_record_buffer(uint idx)
  { return filesort_buffer.get_record_buffer(idx); }

  uchar **get_sort_keys()
  { return filesort_buffer.get_sort_keys(); }

  uchar **alloc_sort_buffer(uint num_records, uint record_length)
  { return filesort_buffer.alloc_sort_buffer(num_records, record_length); }

  void free_sort_buffer()
  { filesort_buffer.free_sort_buffer(); }

  void init_record_pointers()
  { filesort_buffer.init_record_pointers(); }

  size_t sort_buffer_size() const
  { return filesort_buffer.sort_buffer_size(); }
};

class Field_blob;
class Table_triggers_list;

enum enum_table_category
{
  TABLE_UNKNOWN_CATEGORY=0,

  TABLE_CATEGORY_TEMPORARY=1,

  TABLE_CATEGORY_USER=2,

  TABLE_CATEGORY_SYSTEM=3,

  /*
    TODO: Fixing the performance issues of I_S will lead
    to I_S tables in the table cache, which should use
    this table type.
  */
  TABLE_CATEGORY_INFORMATION=4,

  TABLE_CATEGORY_LOG=5,

  TABLE_CATEGORY_PERFORMANCE=6,

  TABLE_CATEGORY_RPL_INFO=7
};
typedef enum enum_table_category TABLE_CATEGORY;

TABLE_CATEGORY get_table_category(const LEX_STRING *db,
                                  const LEX_STRING *name);


extern ulong refresh_version;

typedef struct st_table_field_type
{
  LEX_STRING name;
  LEX_STRING type;
  LEX_STRING cset;
} TABLE_FIELD_TYPE;


typedef struct st_table_field_def
{
  uint count;
  const TABLE_FIELD_TYPE *field;
} TABLE_FIELD_DEF;


class Table_check_intact
{
protected:
  virtual void report_error(uint code, const char *fmt, ...)= 0;

public:
  Table_check_intact() {}
  virtual ~Table_check_intact() {}

  bool check(TABLE *table, const TABLE_FIELD_DEF *table_def);
};


class Wait_for_flush : public MDL_wait_for_subgraph
{
  MDL_context *m_ctx;
  TABLE_SHARE *m_share;
  uint m_deadlock_weight;
public:
  Wait_for_flush(MDL_context *ctx_arg, TABLE_SHARE *share_arg,
               uint deadlock_weight_arg)
    : m_ctx(ctx_arg), m_share(share_arg),
      m_deadlock_weight(deadlock_weight_arg)
  {}

  MDL_context *get_ctx() const { return m_ctx; }

  virtual bool accept_visitor(MDL_wait_for_graph_visitor *dvisitor);

  virtual uint get_deadlock_weight() const;

  Wait_for_flush *next_in_share;
  Wait_for_flush **prev_in_share;
};


typedef I_P_List <Wait_for_flush,
                  I_P_List_adapter<Wait_for_flush,
                                   &Wait_for_flush::next_in_share,
                                   &Wait_for_flush::prev_in_share> >
                 Wait_for_flush_list;


struct TABLE_SHARE
{
  TABLE_SHARE() {}                    /* Remove gcc warning */

  TABLE_CATEGORY table_category;

  /* hash of field names (contains pointers to elements of field array) */
  HASH  name_hash;                      /* hash of field names */
  MEM_ROOT mem_root;
  TYPELIB keynames;                     /* Pointers to keynames */
  TYPELIB fieldnames;                   /* Pointer to fieldnames */
  TYPELIB *intervals;                   /* pointer to interval info */
  mysql_mutex_t LOCK_ha_data;           /* To protect access to ha_data */
  TABLE_SHARE *next, **prev;            /* Link to unused shares */
  Table_cache_element **cache_element;

  /* The following is copied to each TABLE on OPEN */
  Field **field;
  Field **found_next_number_field;
  KEY  *key_info;                       /* data of keys defined for the table */
  uint  *blob_field;                    /* Index to blobs in Field arrray*/

  uchar *default_values;                /* row with default values */
  LEX_STRING comment;                   /* Comment about table */
  const CHARSET_INFO *table_charset;    /* Default charset of string fields */

  MY_BITMAP all_set;
  /*
    Key which is used for looking-up table in table cache and in the list
    of thread's temporary tables. Has the form of:
      "database_name\0table_name\0" + optional part for temporary tables.

    Note that all three 'table_cache_key', 'db' and 'table_name' members
    must be set (and be non-zero) for tables in table cache. They also
    should correspond to each other.
    To ensure this one can use set_table_cache() methods.
  */
  LEX_STRING table_cache_key;
  LEX_STRING db;                        /* Pointer to db */
  LEX_STRING table_name;                /* Table name (for open) */
  LEX_STRING path;                      /* Path to .frm file (from datadir) */
  LEX_STRING normalized_path;           /* unpack_filename(path) */
  LEX_STRING connect_string;

  /* 
     Set of keys in use, implemented as a Bitmap.
     Excludes keys disabled by ALTER TABLE ... DISABLE KEYS.
  */
  key_map keys_in_use;
  key_map keys_for_keyread;
  ha_rows min_rows, max_rows;           /* create information */
  ulong   avg_row_length;               /* create information */
  ulong   version;
  ulong   mysql_version;                /* 0 if .frm is created before 5.0 */
  ulong   reclength;                    /* Recordlength */

  plugin_ref db_plugin;                 /* storage engine plugin */
  inline handlerton *db_type() const    /* table_type for handler */
  { 
    // DBUG_ASSERT(db_plugin);
    return db_plugin ? plugin_data(db_plugin, handlerton*) : NULL;
  }
  enum row_type row_type;               /* How rows are stored */
  enum tmp_table_type tmp_table;

  uint ref_count;                       /* How many TABLE objects uses this */
  uint key_block_size;                  /* create key_block_size, if used */
  uint stats_sample_pages;              /* number of pages to sample during
                                        stats estimation, if used, otherwise 0. */
  enum_stats_auto_recalc stats_auto_recalc; /* Automatic recalc of stats. */
  uint null_bytes, last_null_bit_pos;
  uint fields;                          /* Number of fields */
  uint rec_buff_length;                 /* Size of table->record[] buffer */
  uint keys;                            /* Number of keys defined for the table*/
  uint key_parts;                       /* Number of key parts of all keys
                                           defined for the table
                                        */
  uint max_key_length;                  /* Length of the longest key */
  uint max_unique_length;               /* Length of the longest unique key */
  uint total_key_length;
  uint uniques;                         /* Number of UNIQUE index */
  uint null_fields;                     /* number of null fields */
  uint blob_fields;                     /* number of blob fields */
  uint varchar_fields;                  /* number of varchar fields */
  uint db_create_options;               /* Create options from database */
  uint db_options_in_use;               /* Options in use */
  uint db_record_offset;                /* if HA_REC_IN_SEQ */
  uint rowid_field_offset;              /* Field_nr +1 to rowid field */
  /* Primary key index number, used in TABLE::key_info[] */
  uint primary_key;                     
  uint next_number_index;               /* autoincrement key number */
  uint next_number_key_offset;          /* autoinc keypart offset in a key */
  uint next_number_keypart;             /* autoinc keypart number in a key */
  uint error, open_errno, errarg;       /* error from open_table_def() */
  uint column_bitmap_size;
  uchar frm_version;
  bool null_field_first;
  bool system;                          /* Set if system table (one record) */
  bool crypted;                         /* If .frm file is crypted */
  bool db_low_byte_first;               /* Portable row format */
  bool crashed;
  bool is_view;
  Table_id table_map_id;                   /* for row-based replication */

  /*
    Cache for row-based replication table share checks that does not
    need to be repeated. Possible values are: -1 when cache value is
    not calculated yet, 0 when table *shall not* be replicated, 1 when
    table *may* be replicated.
  */
  int cached_row_logging_check;

  /*
    Storage media to use for this table (unless another storage
    media has been specified on an individual column - in versions
    where that is supported)
  */
  enum ha_storage_media default_storage_media;

  /* Name of the tablespace used for this table */
  char *tablespace;

#ifdef WITH_PARTITION_STORAGE_ENGINE
  /* filled in when reading from frm */
  bool auto_partitioned;
  char *partition_info_str;
  uint  partition_info_str_len;
  uint  partition_info_buffer_size;
  handlerton *default_part_db_type;
#endif

  const TABLE_FIELD_DEF *table_field_def_cache;

  Handler_share *ha_share;

  PSI_table_share *m_psi;

  Wait_for_flush_list m_flush_tickets;

  const File_parser *view_def;


  /*
    Set share's table cache key and update its db and table name appropriately.

    SYNOPSIS
      set_table_cache_key()
        key_buff    Buffer with already built table cache key to be
                    referenced from share.
        key_length  Key length.

    NOTES
      Since 'key_buff' buffer will be referenced from share it should has same
      life-time as share itself.
      This method automatically ensures that TABLE_SHARE::table_name/db have
      appropriate values by using table cache key as their source.
  */

  void set_table_cache_key(char *key_buff, uint key_length)
  {
    table_cache_key.str= key_buff;
    table_cache_key.length= key_length;
    /*
      Let us use the fact that the key is "db/0/table_name/0" + optional
      part for temporary tables.
    */
    db.str=            table_cache_key.str;
    db.length=         strlen(db.str);
    table_name.str=    db.str + db.length + 1;
    table_name.length= strlen(table_name.str);
  }


  /*
    Set share's table cache key and update its db and table name appropriately.

    SYNOPSIS
      set_table_cache_key()
        key_buff    Buffer to be used as storage for table cache key
                    (should be at least key_length bytes).
        key         Value for table cache key.
        key_length  Key length.

    NOTE
      Since 'key_buff' buffer will be used as storage for table cache key
      it should has same life-time as share itself.
  */

  void set_table_cache_key(char *key_buff, const char *key, uint key_length)
  {
    memcpy(key_buff, key, key_length);
    set_table_cache_key(key_buff, key_length);
  }

  inline bool honor_global_locks()
  {
    return ((table_category == TABLE_CATEGORY_USER)
            || (table_category == TABLE_CATEGORY_SYSTEM));
  }

  inline ulonglong get_table_def_version()
  {
    return table_map_id;
  }


  inline bool has_old_version() const
  {
    return version != refresh_version;
  }
  enum enum_table_ref_type get_table_ref_type() const
  {
    if (is_view)
      return TABLE_REF_VIEW;
    switch (tmp_table) {
    case NO_TMP_TABLE:
      return TABLE_REF_BASE_TABLE;
    case SYSTEM_TMP_TABLE:
      return TABLE_REF_I_S_TABLE;
    default:
      return TABLE_REF_TMP_TABLE;
    }
  }
  ulonglong get_table_ref_version() const
  {
    return (tmp_table == SYSTEM_TMP_TABLE) ? 0 : table_map_id.id();
  }

  bool visit_subgraph(Wait_for_flush *waiting_ticket,
                      MDL_wait_for_graph_visitor *gvisitor);

  bool wait_for_old_version(THD *thd, struct timespec *abstime,
                            uint deadlock_weight);
  void destroy();
};


class Blob_mem_storage: public Sql_alloc
{
private:
  MEM_ROOT storage;
  bool truncated_value;
public:
  Blob_mem_storage() :truncated_value(false)
  {
    init_alloc_root(&storage, MAX_FIELD_VARCHARLENGTH, 0);
  }
  ~ Blob_mem_storage()
  {
    free_root(&storage, MYF(0));
  }
  void reset()
  {
    free_root(&storage, MYF(MY_MARK_BLOCKS_FREE));
    truncated_value= false;
  }
  char *store(const char *from, uint length)
  {
    return (char*) memdup_root(&storage, from, length);
  }
  void set_truncated_value(bool is_truncated_value)
  {
    truncated_value= is_truncated_value;
  }
  bool is_truncated_value() { return truncated_value; }
};


/* Information for one open table */
enum index_hint_type
{
  INDEX_HINT_IGNORE,
  INDEX_HINT_USE,
  INDEX_HINT_FORCE
};

/* Bitmap of table's fields */
typedef Bitmap<MAX_FIELDS> Field_map;

struct TABLE
{
  TABLE() {}                               /* Remove gcc warning */
  /*
    Since TABLE instances are often cleared using memset(), do not
    add virtual members and do not inherit from TABLE.
    Otherwise memset() will start overwriting the vtable pointer.
  */

  TABLE_SHARE   *s;
  handler       *file;
  TABLE *next, *prev;

private:
  TABLE *cache_next, **cache_prev;

  /*
    Give Table_cache_element access to the above two members to allow
    using them for linking TABLE objects in a list.
  */
  friend class Table_cache_element;

public:

  THD   *in_use;                        /* Which thread uses this */
  Field **field;                        /* Pointer to fields */

  uchar *record[2];                     /* Pointer to records */
  uchar *write_row_record;              /* Used as optimisation in
                                           THD::write_row */
  uchar *insert_values;                  /* used by INSERT ... UPDATE */
  /* 
    Map of keys that can be used to retrieve all data from this table 
    needed by the query without reading the row.
  */
  key_map covering_keys;
  key_map quick_keys, merge_keys;
  key_map used_keys;  /* Indexes that cover all fields used by the query */
  
  /*
    possible_quick_keys is a superset of quick_keys to use with EXPLAIN of
    JOIN-less commands (single-table UPDATE and DELETE).
    
    When explaining regular JOINs, we use JOIN_TAB::keys to output the 
    "possible_keys" column value. However, it is not available for
    single-table UPDATE and DELETE commands, since they don't use JOIN
    optimizer at the top level. OTOH they directly use the range optimizer,
    that collects all keys usable for range access here.
  */
  key_map possible_quick_keys;

  /*
    A set of keys that can be used in the query that references this
    table.

    All indexes disabled on the table's TABLE_SHARE (see TABLE::s) will be 
    subtracted from this set upon instantiation. Thus for any TABLE t it holds
    that t.keys_in_use_for_query is a subset of t.s.keys_in_use. Generally we 
    must not introduce any new keys here (see setup_tables).

    The set is implemented as a bitmap.
  */
  key_map keys_in_use_for_query;
  /* Map of keys that can be used to calculate GROUP BY without sorting */
  key_map keys_in_use_for_group_by;
  /* Map of keys that can be used to calculate ORDER BY without sorting */
  key_map keys_in_use_for_order_by;
  KEY  *key_info;                       /* data of keys defined for the table */

  Field *next_number_field;             /* Set if next_number is activated */
  Field *found_next_number_field;       /* Set on open */
  Field *fts_doc_id_field;              /* Set if FTS_DOC_ID field is present */

  /* Table's triggers, 0 if there are no of them */
  Table_triggers_list *triggers;
  TABLE_LIST *pos_in_table_list;/* Element referring to this table */
  /* Position in thd->locked_table_list under LOCK TABLES */
  TABLE_LIST *pos_in_locked_tables;
  ORDER         *group;
  const char    *alias;                   /* alias or table name */
  uchar         *null_flags;
  my_bitmap_map *bitmap_init_value;
  MY_BITMAP     def_read_set, def_write_set, tmp_set; /* containers */
  MY_BITMAP     *read_set, *write_set;          /* Active column sets */
  /*
   The ID of the query that opened and is using this table. Has different
   meanings depending on the table type.

   Temporary tables:

   table->query_id is set to thd->query_id for the duration of a statement
   and is reset to 0 once it is closed by the same statement. A non-zero
   table->query_id means that a statement is using the table even if it's
   not the current statement (table is in use by some outer statement).

   Non-temporary tables:

   Under pre-locked or LOCK TABLES mode: query_id is set to thd->query_id
   for the duration of a statement and is reset to 0 once it is closed by
   the same statement. A non-zero query_id is used to control which tables
   in the list of pre-opened and locked tables are actually being used.
  */
  query_id_t    query_id;

  /* 
    For each key that has quick_keys.is_set(key) == TRUE: estimate of #records
    and max #key parts that range access would use.
  */
  ha_rows       quick_rows[MAX_KEY];

  /* Bitmaps of key parts that =const for the entire join. */
  key_part_map  const_key_parts[MAX_KEY];

  uint          quick_key_parts[MAX_KEY];
  uint          quick_n_ranges[MAX_KEY];

  /* 
    Estimate of number of records that satisfy SARGable part of the table
    condition, or table->file->records if no SARGable condition could be
    constructed.
    This value is used by join optimizer as an estimate of number of records
    that will pass the table condition (condition that depends on fields of 
    this table and constants)
  */
  ha_rows       quick_condition_rows;
  table_map     map;                    /* ID bit of table (1,2,4,8,16...) */

  uint          lock_position;          /* Position in MYSQL_LOCK.table */
  uint          lock_data_start;        /* Start pos. in MYSQL_LOCK.locks */
  uint          lock_count;             /* Number of locks */
  uint          tablenr,used_fields;
  uint          temp_pool_slot;         /* Used by intern temp tables */
  uint          db_stat;                /* mode of file as in handler.h */
  int           current_lock;           /* Type of lock on table */

  /*
    0 or JOIN_TYPE_{LEFT|RIGHT}. Currently this is only compared to 0.
    If maybe_null !=0, this table is inner w.r.t. some outer join operation,
    and null_row may be true.
  */
  uint maybe_null;
  /*
    If true, the current table row is considered to have all columns set to 
    NULL, including columns declared as "not null" (see maybe_null).
  */
  my_bool null_row;

  uint8   status;                       /* What's in record[0] */
  my_bool copy_blobs;                   /* copy_blobs when storing */

  /*
    TODO: Each of the following flags take up 8 bits. They can just as easily
    be put into one single unsigned long and instead of taking up 18
    bytes, it would take up 4.
  */
  my_bool force_index;

  my_bool force_index_order;

  my_bool force_index_group;
  my_bool distinct,const_table,no_rows;

  my_bool key_read;
  my_bool no_keyread;
  my_bool locked_by_logger;
  my_bool no_replicate;
  my_bool locked_by_name;
  my_bool fulltext_searched;
  my_bool no_cache;
  /* To signal that the table is associated with a HANDLER statement */
  my_bool open_by_handler;
  /*
    To indicate that a non-null value of the auto_increment field
    was provided by the user or retrieved from the current record.
    Used only in the MODE_NO_AUTO_VALUE_ON_ZERO mode.
  */
  my_bool auto_increment_field_not_null;
  my_bool insert_or_update;             /* Can be used by the handler */
  my_bool alias_name_used;              /* true if table_name is alias */
  my_bool get_fields_in_item_tree;      /* Signal to fix_field */
  my_bool m_needs_reopen;
private:
  bool created; /* For tmp tables. TRUE <=> tmp table has been instantiated.*/
public:
  uint max_keys; /* Size of allocated key_info array. */

  REGINFO reginfo;                      /* field connections */
  MEM_ROOT mem_root;
  Blob_mem_storage *blob_storage;
  GRANT_INFO grant;
  Filesort_info sort;
#ifdef WITH_PARTITION_STORAGE_ENGINE
  partition_info *part_info;            /* Partition related information */
  /* If true, all partitions have been pruned away */
  bool all_partitions_pruned_away;
#endif
  MDL_ticket *mdl_ticket;

  void init(THD *thd, TABLE_LIST *tl);
  bool fill_item_list(List<Item> *item_list) const;
  void reset_item_list(List<Item> *item_list) const;
  void clear_column_bitmaps(void);
  void prepare_for_position(void);
  void mark_columns_used_by_index_no_reset(uint index, MY_BITMAP *map);
  void mark_columns_used_by_index(uint index);
  void mark_auto_increment_column(void);
  void mark_columns_needed_for_update(void);
  void mark_columns_needed_for_delete(void);
  void mark_columns_needed_for_insert(void);
  void mark_columns_per_binlog_row_image(void);
  inline void column_bitmaps_set(MY_BITMAP *read_set_arg,
                                 MY_BITMAP *write_set_arg)
  {
    read_set= read_set_arg;
    write_set= write_set_arg;
    if (file && created)
      file->column_bitmaps_signal();
  }
  inline void column_bitmaps_set_no_signal(MY_BITMAP *read_set_arg,
                                           MY_BITMAP *write_set_arg)
  {
    read_set= read_set_arg;
    write_set= write_set_arg;
  }
  inline void use_all_columns()
  {
    column_bitmaps_set(&s->all_set, &s->all_set);
  }
  inline void default_column_bitmaps()
  {
    read_set= &def_read_set;
    write_set= &def_write_set;
  }
  inline bool needs_reopen()
  { return !db_stat || m_needs_reopen; }
  bool alloc_keys(uint key_count);
  bool add_tmp_key(Field_map *key_parts, char *key_name);
  void use_index(int key_to_save);

  void set_keyread(bool flag)
  {
    DBUG_ASSERT(file);
    if (flag && !key_read)
    {
      key_read= 1;
      if (is_created())
        file->extra(HA_EXTRA_KEYREAD);
    }
    else if (!flag && key_read)
    {
      key_read= 0;
      if (is_created())
        file->extra(HA_EXTRA_NO_KEYREAD);
    }
  }

  bool update_const_key_parts(Item *conds);

  bool check_read_removal(uint index);

  bool is_created() const { return created; }

  void set_created()
  {
    if (created)
      return;
    if (key_read)
      file->extra(HA_EXTRA_KEYREAD);
    created= true;
  }
  void set_deleted()
  {
    created= false;
  }
};


enum enum_schema_table_state
{ 
  NOT_PROCESSED= 0,
  PROCESSED_BY_CREATE_SORT_INDEX,
  PROCESSED_BY_JOIN_EXEC
};

typedef struct st_foreign_key_info
{
  LEX_STRING *foreign_id;
  LEX_STRING *foreign_db;
  LEX_STRING *foreign_table;
  LEX_STRING *referenced_db;
  LEX_STRING *referenced_table;
  LEX_STRING *update_method;
  LEX_STRING *delete_method;
  LEX_STRING *referenced_key_name;
  List<LEX_STRING> foreign_fields;
  List<LEX_STRING> referenced_fields;
} FOREIGN_KEY_INFO;

#define MY_I_S_MAYBE_NULL 1
#define MY_I_S_UNSIGNED   2


#define SKIP_OPEN_TABLE 0                // do not open table
#define OPEN_FRM_ONLY   1                // open FRM file only
#define OPEN_FULL_TABLE 2                // open FRM,MYD, MYI files

typedef struct st_field_info
{
  const char* field_name;
  uint field_length;
  enum enum_field_types field_type;
  int value;
  uint field_flags;        // Field atributes(maybe_null, signed, unsigned etc.)
  const char* old_name;
  uint open_method;
} ST_FIELD_INFO;


struct TABLE_LIST;

typedef struct st_schema_table
{
  const char* table_name;
  ST_FIELD_INFO *fields_info;
  /* Create information_schema table */
  TABLE *(*create_table)  (THD *thd, TABLE_LIST *table_list);
  /* Fill table with data */
  int (*fill_table) (THD *thd, TABLE_LIST *tables, Item *cond);
  /* Handle fileds for old SHOW */
  int (*old_format) (THD *thd, struct st_schema_table *schema_table);
  int (*process_table) (THD *thd, TABLE_LIST *tables, TABLE *table,
                        bool res, LEX_STRING *db_name, LEX_STRING *table_name);
  int idx_field1, idx_field2; 
  bool hidden;
  uint i_s_requested_object;  /* the object we need to open(TABLE | VIEW) */
} ST_SCHEMA_TABLE;


#define JOIN_TYPE_LEFT  1
#define JOIN_TYPE_RIGHT 2

enum enum_derived_type {
  VIEW_ALGORITHM_UNDEFINED = 0,
  VIEW_ALGORITHM_TMPTABLE,
  VIEW_ALGORITHM_MERGE,
  DERIVED_ALGORITHM_TMPTABLE
};

#define VIEW_SUID_INVOKER               0
#define VIEW_SUID_DEFINER               1
#define VIEW_SUID_DEFAULT               2

/* view WITH CHECK OPTION parameter options */
#define VIEW_CHECK_NONE       0
#define VIEW_CHECK_LOCAL      1
#define VIEW_CHECK_CASCADED   2

/* result of view WITH CHECK OPTION parameter check */
#define VIEW_CHECK_OK         0
#define VIEW_CHECK_ERROR      1
#define VIEW_CHECK_SKIP       2

#define MAX_TDC_BLOB_SIZE 65536

class select_union;
class TMP_TABLE_PARAM;

struct Field_translator
{
  Item *item;
  const char *name;
};


/*
  Column reference of a NATURAL/USING join. Since column references in
  joins can be both from views and stored tables, may point to either a
  Field (for tables), or a Field_translator (for views).
*/

class Natural_join_column: public Sql_alloc
{
public:
  Field_translator *view_field;  /* Column reference of merge view. */
  Item_field       *table_field; /* Column reference of table or temp view. */
  TABLE_LIST *table_ref; /* Original base table/view reference. */
  /*
    True if a common join column of two NATURAL/USING join operands. Notice
    that when we have a hierarchy of nested NATURAL/USING joins, a column can
    be common at some level of nesting but it may not be common at higher
    levels of nesting. Thus this flag may change depending on at which level
    we are looking at some column.
  */
  bool is_common;
public:
  Natural_join_column(Field_translator *field_param, TABLE_LIST *tab);
  Natural_join_column(Item_field *field_param, TABLE_LIST *tab);
  const char *name();
  Item *create_item(THD *thd);
  Field *field();
  const char *table_name();
  const char *db_name();
  GRANT_INFO *grant();
};


enum enum_open_type
{
  OT_TEMPORARY_OR_BASE= 0, OT_TEMPORARY_ONLY, OT_BASE_ONLY
};

class Derived_key: public Sql_alloc {
public:
  table_map referenced_by;
  Field_map used_fields;
};

class Index_hint;
class Item_exists_subselect;


/*
  Table reference in the FROM clause.

  These table references can be of several types that correspond to
  different SQL elements. Below we list all types of TABLE_LISTs with
  the necessary conditions to determine when a TABLE_LIST instance
  belongs to a certain type.

  1) table (TABLE_LIST::view == NULL)
     - base table
       (TABLE_LIST::derived == NULL)
     - subquery - TABLE_LIST::table is a temp table
       (TABLE_LIST::derived != NULL)
     - information schema table
       (TABLE_LIST::schema_table != NULL)
       NOTICE: for schema tables TABLE_LIST::field_translation may be != NULL
  2) view (TABLE_LIST::view != NULL)
     - merge    (TABLE_LIST::effective_algorithm == VIEW_ALGORITHM_MERGE)
           also (TABLE_LIST::field_translation != NULL)
     - tmptable (TABLE_LIST::effective_algorithm == VIEW_ALGORITHM_TMPTABLE)
           also (TABLE_LIST::field_translation == NULL)
  3) nested table reference (TABLE_LIST::nested_join != NULL)
     - table sequence - e.g. (t1, t2, t3)
       TODO: how to distinguish from a JOIN?
     - general JOIN
       TODO: how to distinguish from a table sequence?
     - NATURAL JOIN
       (TABLE_LIST::natural_join != NULL)
       - JOIN ... USING
         (TABLE_LIST::join_using_fields != NULL)
     - semi-join
       ;
*/

struct Name_resolution_context;
struct LEX;
struct TABLE_LIST
{
  TABLE_LIST() {}                          /* Remove gcc warning */

  inline void init_one_table(const char *db_name_arg,
                             size_t db_length_arg,
                             const char *table_name_arg,
                             size_t table_name_length_arg,
                             const char *alias_arg,
                             enum thr_lock_type lock_type_arg)
  {
    memset(this, 0, sizeof(*this));
    db= (char*) db_name_arg;
    db_length= db_length_arg;
    table_name= (char*) table_name_arg;
    table_name_length= table_name_length_arg;
    alias= (char*) alias_arg;
    lock_type= lock_type_arg;
    mdl_request.init(MDL_key::TABLE, db, table_name,
                     (lock_type >= TL_WRITE_ALLOW_WRITE) ?
                     MDL_SHARED_WRITE : MDL_SHARED_READ,
                     MDL_TRANSACTION);
    callback_func= 0;
  }

  static TABLE_LIST *new_nested_join(MEM_ROOT *allocator,
                                     const char *alias,
                                     TABLE_LIST *embedding,
                                     List<TABLE_LIST> *belongs_to,
                                     class st_select_lex *select);

  /*
    List of tables local to a subquery or the top-level SELECT (used by
    SQL_I_List). Considers views as leaves (unlike 'next_leaf' below).
    Created at parse time in st_select_lex::add_table_to_list() ->
    table_list.link_in_list().
  */
  TABLE_LIST *next_local;
  /* link in a global list of all queries tables */
  TABLE_LIST *next_global, **prev_global;
  char          *db, *alias, *table_name, *schema_table_name;
  char          *option;                /* Used by cache index  */
  Name_resolution_context *context_of_embedding;

private:
  Item          *m_join_cond;           /* Used with outer join */
public:
  Item         **join_cond_ref() { return &m_join_cond; }
  Item          *join_cond() const { return m_join_cond; }
  Item          *set_join_cond(Item *val)
                 { return m_join_cond= val; }
  /*
    The structure of the join condition presented in the member above
    can be changed during certain optimizations. This member
    contains a snapshot of AND-OR structure of the join condition
    made after permanent transformations of the parse tree, and is
    used to restore the join condition before every reexecution of a prepared
    statement or stored procedure.
  */
  Item          *prep_join_cond;

  Item          *sj_on_expr;            /* Synthesized semijoin condition */
  /*
    (Valid only for semi-join nests) Bitmap of tables that are within the
    semi-join (this is different from bitmap of all nest's children because
    tables that were pulled out of the semi-join nest remain listed as
    nest's children).
  */
  table_map     sj_inner_tables;

  COND_EQUAL    *cond_equal;            /* Used with outer join */
  /*
    During parsing - left operand of NATURAL/USING join where 'this' is
    the right operand. After parsing (this->natural_join == this) iff
    'this' represents a NATURAL or USING join operation. Thus after
    parsing 'this' is a NATURAL/USING join iff (natural_join != NULL).
  */
  TABLE_LIST *natural_join;
  /*
    True if 'this' represents a nested join that is a NATURAL JOIN.
    For one of the operands of 'this', the member 'natural_join' points
    to the other operand of 'this'.
  */
  bool is_natural_join;
  /* Field names in a USING clause for JOIN ... USING. */
  List<String> *join_using_fields;
  /*
    Explicitly store the result columns of either a NATURAL/USING join or
    an operand of such a join.
  */
  List<Natural_join_column> *join_columns;
  /* TRUE if join_columns contains all columns of this table reference. */
  bool is_join_columns_complete;

  /*
    List of nodes in a nested join tree, that should be considered as
    leaves with respect to name resolution. The leaves are: views,
    top-most nodes representing NATURAL/USING joins, subqueries, and
    base tables. All of these TABLE_LIST instances contain a
    materialized list of columns. The list is local to a subquery.
  */
  TABLE_LIST *next_name_resolution_table;
  /* Index names in a "... JOIN ... USE/IGNORE INDEX ..." clause. */
  List<Index_hint> *index_hints;
  TABLE        *table;                          /* opened table */
  Table_id table_id; /* table id (from binlog) for opened table */
  /*
    select_result for derived table to pass it from table creation to table
    filling procedure
  */
  select_union  *derived_result;
  /*
    Reference from aux_tables to local list entry of main select of
    multi-delete statement:
    delete t1 from t2,t1 where t1.a<'B' and t2.b=t1.b;
    here it will be reference of first occurrence of t1 to second (as you
    can see this lists can't be merged)
  */
  TABLE_LIST    *correspondent_table;
  st_select_lex_unit *derived;          /* SELECT_LEX_UNIT of derived table */
  /*
    TRUE <=> all possible keys for a derived table were collected and
    could be re-used while statement re-execution.
  */
  bool derived_keys_ready;
  ST_SCHEMA_TABLE *schema_table;        /* Information_schema table */
  st_select_lex *schema_select_lex;
  /*
    True when the view field translation table is used to convert
    schema table fields for backwards compatibility with SHOW command.
  */
  bool schema_table_reformed;
  TMP_TABLE_PARAM *schema_table_param;
  /* link to select_lex where this table was used */
  st_select_lex *select_lex;
  LEX *view;                    /* link on VIEW lex for merging */
  Field_translator *field_translation;  /* array of VIEW fields */
  /* pointer to element after last one in translation table above */
  Field_translator *field_translation_end;
  /*
    List (based on next_local) of underlying tables of this view. I.e. it
    does not include the tables of subqueries used in the view. Is set only
    for merged views.
  */
  TABLE_LIST    *merge_underlying_list;
  /*
    - 0 for base tables
    - in case of the view it is the list of all (not only underlying
    tables but also used in subquery ones) tables of the view.
  */
  List<TABLE_LIST> *view_tables;
  /* most upper view this table belongs to */
  TABLE_LIST    *belong_to_view;
  /*
    The view directly referencing this table
    (non-zero only for merged underlying tables of a view).
  */
  TABLE_LIST    *referencing_view;
  /* Ptr to parent MERGE table list item. See top comment in ha_myisammrg.cc */
  TABLE_LIST    *parent_l;
  /*
    Security  context (non-zero only for tables which belong
    to view with SQL SECURITY DEFINER)
  */
  Security_context *security_ctx;
  /*
    This view security context (non-zero only for views with
    SQL SECURITY DEFINER)
  */
  Security_context *view_sctx;
  /*
    List of all base tables local to a subquery including all view
    tables. Unlike 'next_local', this in this list views are *not*
    leaves. Created in setup_tables() -> make_leaves_list().
  */
  bool allowed_show;
  TABLE_LIST    *next_leaf;
  Item          *where;                 /* VIEW WHERE clause condition */
  Item          *check_option;          /* WITH CHECK OPTION condition */
  LEX_STRING    select_stmt;            /* text of (CREATE/SELECT) statement */
  LEX_STRING    md5;                    /* md5 of query text */
  LEX_STRING    source;                 /* source of CREATE VIEW */
  LEX_STRING    view_db;                /* saved view database */
  LEX_STRING    view_name;              /* saved view name */
  LEX_STRING    timestamp;              /* GMT time stamp of last operation */
  st_lex_user   definer;                /* definer of view */
  ulonglong     file_version;           /* version of file's field set */
  ulonglong     updatable_view;         /* VIEW can be updated */
  ulonglong     algorithm;
  ulonglong     view_suid;              /* view is suid (TRUE dy default) */
  ulonglong     with_check;             /* WITH CHECK OPTION */
  /*
    effective value of WITH CHECK OPTION (differ for temporary table
    algorithm)
  */
  uint8         effective_with_check;
  enum_derived_type effective_algorithm;
  GRANT_INFO    grant;
  /* data need by some engines in query cache*/
  ulonglong     engine_data;
  /* call back function for asking handler about caching in query cache */
  qc_engine_callback callback_func;
  thr_lock_type lock_type;
  uint          outer_join;             /* Which join type */
  uint          shared;                 /* Used in multi-upd */
  size_t        db_length;
  size_t        table_name_length;
  bool          updatable;              /* VIEW/TABLE can be updated now */
  bool          straight;               /* optimize with prev table */
  bool          updating;               /* for replicate-do/ignore table */
  bool          force_index;            /* prefer index over table scan */
  bool          ignore_leaves;          /* preload only non-leaf nodes */
  table_map     dep_tables;             /* tables the table depends on      */
  table_map     on_expr_dep_tables;     /* tables on expression depends on  */
  struct st_nested_join *nested_join;   /* if the element is a nested join  */
  TABLE_LIST *embedding;             /* nested join containing the table */
  List<TABLE_LIST> *join_list;/* join list the table belongs to   */
  bool          cacheable_table;        /* stop PS caching */
  /* used in multi-upd/views privilege check */
  bool          table_in_first_from_clause;
  enum enum_open_type open_type;
  /* TRUE if this merged view contain auto_increment field */
  bool          contain_auto_increment;
  bool          multitable_view;        /* TRUE iff this is multitable view */
  bool          compact_view_format;    /* Use compact format for SHOW CREATE VIEW */
  /* view where processed */
  bool          where_processed;
  /* TRUE <=> VIEW CHECK OPTION expression has been processed */
  bool          check_option_processed;
  /* FRMTYPE_ERROR if any type is acceptable */
  enum frm_type_enum required_type;
  char          timestamp_buffer[20];   /* buffer for timestamp (19+1) */
  /*
    This TABLE_LIST object is just placeholder for prelocking, it will be
    used for implicit LOCK TABLES only and won't be used in real statement.
  */
  bool          prelocking_placeholder;
  enum
  {
    /* Normal open. */
    OPEN_NORMAL= 0,
    /* Associate a table share only if the the table exists. */
    OPEN_IF_EXISTS,
    /*
      Associate a table share only if the the table exists.
      Also upgrade metadata lock to exclusive if table doesn't exist.
    */
    OPEN_FOR_CREATE,
    /* Don't associate a table share. */
    OPEN_STUB
  } open_strategy;
  bool          internal_tmp_table;
  bool          is_alias;
  bool          is_fqtn;


  /* View creation context. */

  View_creation_ctx *view_creation_ctx;

  /*
    Attributes to save/load view creation context in/from frm-file.

    Ther are required only to be able to use existing parser to load
    view-definition file. As soon as the parser parsed the file, view
    creation context is initialized and the attributes become redundant.

    These attributes MUST NOT be used for any purposes but the parsing.
  */

  LEX_STRING view_client_cs_name;
  LEX_STRING view_connection_cl_name;

  /*
    View definition (SELECT-statement) in the UTF-form.
  */

  LEX_STRING view_body_utf8;

   /* End of view definition context. */
  /* List of possible keys. Valid only for materialized derived tables/views. */
  List<Derived_key> derived_key_list;

  uint8 trg_event_map;
  /* TRUE <=> this table is a const one and was optimized away. */
  bool optimized_away;
  uint i_s_requested_object;
  bool has_db_lookup_value;
  bool has_table_lookup_value;
  uint table_open_method;
  enum enum_schema_table_state schema_table_state;

  MDL_request mdl_request;

#ifdef WITH_PARTITION_STORAGE_ENGINE
  /* List to carry partition names from PARTITION (...) clause in statement */
  List<String> *partition_names;
#endif /* WITH_PARTITION_STORAGE_ENGINE */

  void calc_md5(char *buffer);
  void set_underlying_merge();
  int view_check_option(THD *thd, bool ignore_failure) const;
  bool setup_underlying(THD *thd);
  void cleanup_items();
  bool placeholder()
  {
    return derived || view || schema_table || !table;
  }
  void print(THD *thd, String *str, enum_query_type query_type);
  bool check_single_table(TABLE_LIST **table, table_map map,
                          TABLE_LIST *view);
  bool set_insert_values(MEM_ROOT *mem_root);
  void hide_view_error(THD *thd);
  TABLE_LIST *find_underlying_table(TABLE *table);
  TABLE_LIST *first_leaf_for_name_resolution();
  TABLE_LIST *last_leaf_for_name_resolution();
  bool is_leaf_for_name_resolution();
  inline const TABLE_LIST *top_table() const
    { return belong_to_view ? belong_to_view : this; }

  inline TABLE_LIST *top_table()
  {
    return
      const_cast<TABLE_LIST*>(const_cast<const TABLE_LIST*>(this)->top_table());
  }

  inline bool prepare_check_option(THD *thd)
  {
    bool res= FALSE;
    if (effective_with_check)
      res= prep_check_option(thd, effective_with_check);
    return res;
  }
  inline bool prepare_where(THD *thd, Item **conds,
                            bool no_where_clause)
  {
    if (effective_algorithm == VIEW_ALGORITHM_MERGE)
      return prep_where(thd, conds, no_where_clause);
    return FALSE;
  }
  inline bool uses_materialization() const
  {
    return (effective_algorithm == VIEW_ALGORITHM_TMPTABLE ||
            effective_algorithm == DERIVED_ALGORITHM_TMPTABLE);
  }
  inline bool is_view_or_derived() const
  {
    return (effective_algorithm != VIEW_ALGORITHM_UNDEFINED);
  }
  bool materializable_is_const() const;

  void register_want_access(ulong want_access);
  bool prepare_security(THD *thd);
#ifndef NO_EMBEDDED_ACCESS_CHECKS
  Security_context *find_view_security_context(THD *thd);
  bool prepare_view_securety_context(THD *thd);
#endif
  /*
    Cleanup for re-execution in a prepared statement or a stored
    procedure.
  */
  void reinit_before_use(THD *thd);
  Item_subselect *containing_subselect();

  /* 
    Compiles the tagged hints list and fills up TABLE::keys_in_use_for_query,
    TABLE::keys_in_use_for_group_by, TABLE::keys_in_use_for_order_by,
    TABLE::force_index and TABLE::covering_keys.
  */
  bool process_index_hints(TABLE *table);

  inline
  bool is_table_ref_id_equal(TABLE_SHARE *s) const
  {
    return (m_table_ref_type == s->get_table_ref_type() &&
            m_table_ref_version == s->get_table_ref_version());
  }

  inline
  void set_table_ref_id(TABLE_SHARE *s)
  { set_table_ref_id(s->get_table_ref_type(), s->get_table_ref_version()); }

  inline
  void set_table_ref_id(enum_table_ref_type table_ref_type_arg,
                        ulonglong table_ref_version_arg)
  {
    m_table_ref_type= table_ref_type_arg;
    m_table_ref_version= table_ref_version_arg;
  }

  bool is_anonymous_derived_table() const { return derived && !view; }

  uint query_block_id() const;

  char *get_db_name() const { return view != NULL ? view_db.str : db; }

  char *get_table_name() const { return view != NULL ? view_name.str : table_name; }
  int fetch_number_of_rows();
  bool update_derived_keys(Field*, Item**, uint);
  bool generate_keys();
  bool handle_derived(LEX *lex, bool (*processor)(THD*, LEX*, TABLE_LIST*));
  st_select_lex_unit *get_unit() const;

  TABLE_LIST *outer_join_nest() const
  {
    if (!embedding)
      return NULL;
    if (embedding->sj_on_expr)
      return embedding->embedding;
    return embedding;
  }

private:
  bool prep_check_option(THD *thd, uint8 check_opt_type);
  bool prep_where(THD *thd, Item **conds, bool no_where_clause);
  enum enum_table_ref_type m_table_ref_type;
  ulonglong m_table_ref_version;
};


struct st_position;
  
class Item;

/*
  Iterator over the fields of a generic table reference.
*/

class Field_iterator: public Sql_alloc
{
public:
  Field_iterator() {}                         /* Remove gcc warning */
  virtual ~Field_iterator() {}
  virtual void set(TABLE_LIST *)= 0;
  virtual void next()= 0;
  virtual bool end_of_fields()= 0;              /* Return 1 at end of list */
  virtual const char *name()= 0;
  virtual Item *create_item(THD *)= 0;
  virtual Field *field()= 0;
};


/* 
  Iterator over the fields of a base table, view with temporary
  table, or subquery.
*/

class Field_iterator_table: public Field_iterator
{
  Field **ptr;
public:
  Field_iterator_table() :ptr(0) {}
  void set(TABLE_LIST *table) { ptr= table->table->field; }
  void set_table(TABLE *table) { ptr= table->field; }
  void next() { ptr++; }
  bool end_of_fields() { return *ptr == 0; }
  const char *name();
  Item *create_item(THD *thd);
  Field *field() { return *ptr; }
};


/* Iterator over the fields of a merge view. */

class Field_iterator_view: public Field_iterator
{
  Field_translator *ptr, *array_end;
  TABLE_LIST *view;
public:
  Field_iterator_view() :ptr(0), array_end(0) {}
  void set(TABLE_LIST *table);
  void next() { ptr++; }
  bool end_of_fields() { return ptr == array_end; }
  const char *name();
  Item *create_item(THD *thd);
  Item **item_ptr() {return &ptr->item; }
  Field *field() { return 0; }
  inline Item *item() { return ptr->item; }
  Field_translator *field_translator() { return ptr; }
};


/*
  Field_iterator interface to the list of materialized fields of a
  NATURAL/USING join.
*/

class Field_iterator_natural_join: public Field_iterator
{
  List_iterator_fast<Natural_join_column> column_ref_it;
  Natural_join_column *cur_column_ref;
public:
  Field_iterator_natural_join() :cur_column_ref(NULL) {}
  ~Field_iterator_natural_join() {}
  void set(TABLE_LIST *table);
  void next();
  bool end_of_fields() { return !cur_column_ref; }
  const char *name() { return cur_column_ref->name(); }
  Item *create_item(THD *thd) { return cur_column_ref->create_item(thd); }
  Field *field() { return cur_column_ref->field(); }
  Natural_join_column *column_ref() { return cur_column_ref; }
};


/*
  Generic iterator over the fields of an arbitrary table reference.

  DESCRIPTION
    This class unifies the various ways of iterating over the columns
    of a table reference depending on the type of SQL entity it
    represents. If such an entity represents a nested table reference,
    this iterator encapsulates the iteration over the columns of the
    members of the table reference.

  IMPLEMENTATION
    The implementation assumes that all underlying NATURAL/USING table
    references already contain their result columns and are linked into
    the list TABLE_LIST::next_name_resolution_table.
*/

class Field_iterator_table_ref: public Field_iterator
{
  TABLE_LIST *table_ref, *first_leaf, *last_leaf;
  Field_iterator_table        table_field_it;
  Field_iterator_view         view_field_it;
  Field_iterator_natural_join natural_join_it;
  Field_iterator *field_it;
  void set_field_iterator();
public:
  Field_iterator_table_ref() :field_it(NULL) {}
  void set(TABLE_LIST *table);
  void next();
  bool end_of_fields()
  { return (table_ref == last_leaf && field_it->end_of_fields()); }
  const char *name() { return field_it->name(); }
  const char *get_table_name();
  const char *get_db_name();
  GRANT_INFO *grant();
  Item *create_item(THD *thd) { return field_it->create_item(thd); }
  Field *field() { return field_it->field(); }
  Natural_join_column *get_or_create_column_ref(THD *thd, TABLE_LIST *parent_table_ref);
  Natural_join_column *get_natural_column_ref();
};

struct Semijoin_mat_optimize
{
  struct st_position *positions;
  bool lookup_allowed;
  bool scan_allowed;
  double expected_rowcount;
  Cost_estimate materialization_cost;
  Cost_estimate lookup_cost;
  Cost_estimate scan_cost;
  Item_field **mat_fields;
};

typedef struct st_nested_join
{
  List<TABLE_LIST>  join_list;       /* list of elements in the nested join */
  table_map         used_tables;     /* bitmap of tables in the nested join */
  table_map         not_null_tables; /* tables that rejects nulls           */
  struct st_join_table *first_nested;
  uint              nj_total;
  uint              nj_counter;
  nested_join_map   nj_map;
  table_map         sj_depends_on;
  table_map         sj_corr_tables;
  uint query_block_id;
  /*
    Lists of trivially-correlated expressions from the outer and inner tables
    of the semi-join, respectively.
  */
  List<Item>        sj_outer_exprs, sj_inner_exprs;
  Semijoin_mat_optimize sjm;
} NESTED_JOIN;


typedef struct st_changed_table_list
{
  struct        st_changed_table_list *next;
  char          *key;
  uint32        key_length;
} CHANGED_TABLE_LIST;


typedef struct st_open_table_list{
  struct st_open_table_list *next;
  char  *db,*table;
  uint32 in_use,locked;
} OPEN_TABLE_LIST;


static inline my_bitmap_map *tmp_use_all_columns(TABLE *table,
                                                 MY_BITMAP *bitmap)
{
  my_bitmap_map *old= bitmap->bitmap;
  bitmap->bitmap= table->s->all_set.bitmap;// does not repoint last_word_ptr
  return old;
}


static inline void tmp_restore_column_map(MY_BITMAP *bitmap,
                                          my_bitmap_map *old)
{
  bitmap->bitmap= old;
}

/* The following is only needed for debugging */

static inline my_bitmap_map *dbug_tmp_use_all_columns(TABLE *table,
                                                      MY_BITMAP *bitmap)
{
#ifndef DBUG_OFF
  return tmp_use_all_columns(table, bitmap);
#else
  return 0;
#endif
}

static inline void dbug_tmp_restore_column_map(MY_BITMAP *bitmap,
                                               my_bitmap_map *old)
{
#ifndef DBUG_OFF
  tmp_restore_column_map(bitmap, old);
#endif
}


/* 
  Variant of the above : handle both read and write sets.
  Provide for the possiblity of the read set being the same as the write set
*/
static inline void dbug_tmp_use_all_columns(TABLE *table,
                                            my_bitmap_map **save,
                                            MY_BITMAP *read_set,
                                            MY_BITMAP *write_set)
{
#ifndef DBUG_OFF
  save[0]= read_set->bitmap;
  save[1]= write_set->bitmap;
  (void) tmp_use_all_columns(table, read_set);
  (void) tmp_use_all_columns(table, write_set);
#endif
}


static inline void dbug_tmp_restore_column_maps(MY_BITMAP *read_set,
                                                MY_BITMAP *write_set,
                                                my_bitmap_map **old)
{
#ifndef DBUG_OFF
  tmp_restore_column_map(read_set, old[0]);
  tmp_restore_column_map(write_set, old[1]);
#endif
}


size_t max_row_length(TABLE *table, const uchar *data);


void init_mdl_requests(TABLE_LIST *table_list);

int open_table_from_share(THD *thd, TABLE_SHARE *share, const char *alias,
                          uint db_stat, uint prgflag, uint ha_open_flags,
                          TABLE *outparam, bool is_create_table);
TABLE_SHARE *alloc_table_share(TABLE_LIST *table_list, const char *key,
                               uint key_length);
void init_tmp_table_share(THD *thd, TABLE_SHARE *share, const char *key,
                          uint key_length,
                          const char *table_name, const char *path);
void free_table_share(TABLE_SHARE *share);
int open_table_def(THD *thd, TABLE_SHARE *share, uint db_flags);
void open_table_error(TABLE_SHARE *share, int error, int db_errno, int errarg);
void update_create_info_from_table(HA_CREATE_INFO *info, TABLE *form);
enum_ident_name_check check_and_convert_db_name(LEX_STRING *db,
                                                bool preserve_lettercase);
bool check_column_name(const char *name);
enum_ident_name_check check_table_name(const char *name, size_t length,
                                       bool check_for_path_chars);
int rename_file_ext(const char * from,const char * to,const char * ext);
char *get_field(MEM_ROOT *mem, Field *field);
bool get_field(MEM_ROOT *mem, Field *field, class String *res);

int closefrm(TABLE *table, bool free_share);
int read_string(File file, uchar* *to, size_t length);
void free_blobs(TABLE *table);
void free_field_buffers_larger_than(TABLE *table, uint32 size);
int set_zone(int nr,int min_zone,int max_zone);
ulong get_form_pos(File file, uchar *head, TYPELIB *save_names);
ulong make_new_entry(File file,uchar *fileinfo,TYPELIB *formnames,
                     const char *newname);
ulong next_io_size(ulong pos);
void append_unescaped(String *res, const char *pos, uint length);
File create_frm(THD *thd, const char *name, const char *db,
                const char *table, uint reclength, uchar *fileinfo,
                HA_CREATE_INFO *create_info, uint keys, KEY *key_info);
char *fn_rext(char *name);

/* performance schema */
extern LEX_STRING PERFORMANCE_SCHEMA_DB_NAME;

extern LEX_STRING GENERAL_LOG_NAME;
extern LEX_STRING SLOW_LOG_NAME;

/* information schema */
extern LEX_STRING INFORMATION_SCHEMA_NAME;
extern LEX_STRING MYSQL_SCHEMA_NAME;

/* replication's tables */
extern LEX_STRING RLI_INFO_NAME;
extern LEX_STRING MI_INFO_NAME;
extern LEX_STRING WORKER_INFO_NAME;

inline bool is_infoschema_db(const char *name, size_t len)
{
  return (INFORMATION_SCHEMA_NAME.length == len &&
          !my_strcasecmp(system_charset_info,
                         INFORMATION_SCHEMA_NAME.str, name));
}

inline bool is_infoschema_db(const char *name)
{
  return !my_strcasecmp(system_charset_info,
                        INFORMATION_SCHEMA_NAME.str, name);
}

TYPELIB *typelib(MEM_ROOT *mem_root, List<String> &strings);

inline bool is_user_table(TABLE * table)
{
  const char *name= table->s->table_name.str;
  return strncmp(name, tmp_file_prefix, tmp_file_prefix_length);
}

inline void mark_as_null_row(TABLE *table)
{
  table->null_row=1;
  table->status|=STATUS_NULL_ROW;
  memset(table->null_flags, 255, table->s->null_bytes);
}

bool is_simple_order(ORDER *order);

#endif /* MYSQL_CLIENT */

#endif /* TABLE_INCLUDED */