/* Copyright (C) 2008-2018 Kentoku Shiba
   Copyright (C) 2023 MariaDB plc

  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

  There are several kinds of spider parameters.

  - sysvar/thdvar that are not table parameters. These variables do
    not appear in a `SPIDER_SHARE`. Examples include `support_xa` and
    `conn_recycle_mode`. Their values are commonly retrieved by
    `SPIDER_SYSVAR_VALUE_FUNC()` and `SPIDER_THDVAR_VALUE_FUNC()`
  - sysvar/thdvar that are also table parameters. These variables
    commonly appear in a `SPIDER_SHARE`. Examples include
    `read_only_mode` and `use_table_charset`. Table parameter values
    override variable values, and their values are commonly retrieved
    by `SPIDER_SYSVAR_OVERRIDE_VALUE_FUNC()` and
    `SPIDER_THDVAR_OVERRIDE_VALUE_FUNC()`.
  - table parameters that are not sysvar/thdvar. Examples include
    host and username. They are not handled in this file which is only
    concerned with global/session variables
*/

#define MYSQL_SERVER 1
#include <my_global.h>
#include "mysql_version.h"
#include "sql_priv.h"
#include "probes_mysql.h"
#include "sql_class.h"
#include "sql_partition.h"
#include <my_getopt.h>
#include "spd_err.h"
#include "spd_db_include.h"
#include "spd_include.h"
#include "ha_spider.h"
#include "spd_table.h"
#include "spd_trx.h"

extern struct st_mysql_plugin spider_i_s_alloc_mem;
extern struct st_mysql_plugin spider_i_s_wrapper_protocols;
extern struct st_maria_plugin spider_i_s_alloc_mem_maria;
extern struct st_maria_plugin spider_i_s_wrapper_protocols_maria;

extern volatile ulonglong spider_mon_table_cache_version;
extern volatile ulonglong spider_mon_table_cache_version_req;

/*
  Define a function returning the value of a global variable.
*/
#define SPIDER_SYSVAR_VALUE_FUNC(param_type, param_name)             \
  param_type spider_param_ ## param_name()                           \
  {                                                                  \
    return SYSVAR(param_name);                                       \
  }

/*
  Define a function returning the value of a session variable.
*/
#define SPIDER_THDVAR_VALUE_FUNC(param_type, param_name)             \
  param_type spider_param_ ## param_name(THD *thd)                   \
  {                                                                  \
    return THDVAR(thd, param_name);                                  \
  }

/*
 Define a function returning the value of a table param that is also a
 global variable.

 If the table param value is not -1, use the table param value.
 Otherwise if the variable value is not -1, use the variable value.
 Otherwise use the default variable value.
*/
#define SPIDER_SYSVAR_OVERRIDE_VALUE_FUNC(param_type, param_name)   \
  param_type spider_param_ ## param_name(param_type param_name)     \
  {                                                                 \
    return param_name != -1 ? param_name :                          \
      SYSVAR(param_name) != -1 ? SYSVAR(param_name) :               \
      MYSQL_SYSVAR_NAME(param_name).def_val;                        \
  }

/*
 Define a function returning the value of a table param that is also a
 session variable.

 If the table param value is not -1, use the table param value.
 Otherwise if the variable value is not -1, use the variable value.
 Otherwise use the default variable value.
*/
#define SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(param_type, param_name)       \
  param_type spider_param_ ## param_name(THD* thd,                      \
                                         param_type param_name)         \
  {                                                                     \
    return param_name != -1 ? param_name :                              \
      THDVAR(thd, param_name) != -1 ? THDVAR(thd, param_name) :         \
      MYSQL_SYSVAR_NAME(param_name).def_val;                            \
  }

extern handlerton *spider_hton_ptr;
static void spider_trx_status_var(THD *thd, SHOW_VAR *var, void *buff,
                                 ulonglong SPIDER_TRX::*counter)
{
  DBUG_ENTER("spider_direct_update");
  var->type = SHOW_LONGLONG;
  var->value= buff;
  if (thd != current_thd)
    mysql_mutex_lock(&thd->LOCK_thd_data);
  SPIDER_TRX *trx = (SPIDER_TRX*)thd_get_ha_data(thd, spider_hton_ptr);
  *(ulonglong*)buff= trx ? trx->*counter : 0;
  if (thd != current_thd)
    mysql_mutex_unlock(&thd->LOCK_thd_data);
  DBUG_VOID_RETURN;
}


static int spider_direct_update(THD *thd, SHOW_VAR *var, void *buff,
                                system_status_var *, enum_var_type)
{
  DBUG_ENTER("spider_direct_update");
  spider_trx_status_var(thd, var, buff, &SPIDER_TRX::direct_update_count);
  DBUG_RETURN(0);
}

static int spider_direct_delete(THD *thd, SHOW_VAR *var, void *buff,
                                system_status_var *, enum_var_type)
{
  DBUG_ENTER("spider_direct_delete");
  spider_trx_status_var(thd, var, buff, &SPIDER_TRX::direct_delete_count);
  DBUG_RETURN(0);
}

static int spider_direct_order_limit(THD *thd, SHOW_VAR *var, void *buff,
                                     system_status_var *, enum_var_type)
{
  DBUG_ENTER("spider_direct_order_limit");
  spider_trx_status_var(thd, var, buff, &SPIDER_TRX::direct_order_limit_count);
  DBUG_RETURN(0);
}

static int spider_direct_aggregate(THD *thd, SHOW_VAR *var, void *buff,
                                   system_status_var *, enum_var_type)
{
  DBUG_ENTER("spider_direct_aggregate");
  spider_trx_status_var(thd, var, buff, &SPIDER_TRX::direct_aggregate_count);
  DBUG_RETURN(0);
}

static int spider_parallel_search(THD *thd, SHOW_VAR *var, void *buff,
                                  system_status_var *, enum_var_type)
{
  DBUG_ENTER("spider_parallel_search");
  spider_trx_status_var(thd, var, buff, &SPIDER_TRX::parallel_search_count);
  DBUG_RETURN(0);
}

struct st_mysql_show_var spider_status_variables[] =
{
  {"Spider_mon_table_cache_version",
    (char *) &spider_mon_table_cache_version, SHOW_LONGLONG},
  {"Spider_mon_table_cache_version_req",
    (char *) &spider_mon_table_cache_version_req, SHOW_LONGLONG},
#ifdef SPIDER_HAS_SHOW_SIMPLE_FUNC
  {"Spider_direct_update", (char *) &spider_direct_update, SHOW_SIMPLE_FUNC},
  {"Spider_direct_delete", (char *) &spider_direct_delete, SHOW_SIMPLE_FUNC},
#else
  {"Spider_direct_update", (char *) &spider_direct_update, SHOW_FUNC},
  {"Spider_direct_delete", (char *) &spider_direct_delete, SHOW_FUNC},
#endif
#ifdef SPIDER_HAS_SHOW_SIMPLE_FUNC
  {"Spider_direct_order_limit",
    (char *) &spider_direct_order_limit, SHOW_SIMPLE_FUNC},
  {"Spider_direct_aggregate",
    (char *) &spider_direct_aggregate, SHOW_SIMPLE_FUNC},
  {"Spider_parallel_search",
    (char *) &spider_parallel_search, SHOW_SIMPLE_FUNC},
#else
  {"Spider_direct_order_limit",
    (char *) &spider_direct_order_limit, SHOW_FUNC},
  {"Spider_direct_aggregate",
    (char *) &spider_direct_aggregate, SHOW_FUNC},
  {"Spider_parallel_search",
    (char *) &spider_parallel_search, SHOW_FUNC},
#endif
  {NullS, NullS, SHOW_LONG}
};

typedef DECLARE_MYSQL_THDVAR_SIMPLE(thdvar_int_t, int);
extern bool throw_bounds_warning(THD *thd, const char *name, bool fixed,
  bool is_unsignd, longlong v);

static my_bool spider_support_xa;
static MYSQL_SYSVAR_BOOL(
  support_xa,
  spider_support_xa,
  PLUGIN_VAR_OPCMDARG | PLUGIN_VAR_READONLY,
  "XA support",
  NULL,
  NULL,
  TRUE
);

static void spider_var_deprecated_int(THD *thd, st_mysql_sys_var *,
                                      void *var_ptr, const void *save)
{
  int val= *static_cast<const int *>(save);
  *static_cast<int *>(var_ptr)= val;
  if (val == -1)
  {
    push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
                        HA_ERR_UNSUPPORTED,
                        "The option value -1 (fallback to default) is "
                        "deprecated and will be removed in a future release");
  }
}

static void spider_var_deprecated_longlong(THD *thd, st_mysql_sys_var *,
                                           void *var_ptr, const void *save)
{
  longlong val= *static_cast<const longlong *>(save);
  *static_cast<longlong *>(var_ptr)= val;
  if (val == -1)
  {
    push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
                        HA_ERR_UNSUPPORTED,
                        "The option value -1 (fallback to default) is "
                        "deprecated and will be removed in a future release");
  }
}

SPIDER_SYSVAR_VALUE_FUNC(my_bool, support_xa)

static my_bool spider_connect_mutex;
static MYSQL_SYSVAR_BOOL(
  connect_mutex,
  spider_connect_mutex,
  PLUGIN_VAR_OPCMDARG,
  "Use mutex at connecting",
  NULL,
  NULL,
  FALSE
);

SPIDER_SYSVAR_VALUE_FUNC(my_bool, connect_mutex)

static uint spider_connect_error_interval;
/*
  0-: interval
 */
static MYSQL_SYSVAR_UINT(
  connect_error_interval,
  spider_connect_error_interval,
  PLUGIN_VAR_RQCMDARG,
  "Return same error code until interval passes if connection is failed",
  NULL,
  NULL,
  1,
  0,
  4294967295U,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(uint, connect_error_interval)

static uint spider_table_init_error_interval;
/*
  0-: interval
 */
static MYSQL_SYSVAR_UINT(
  table_init_error_interval,
  spider_table_init_error_interval,
  PLUGIN_VAR_RQCMDARG,
  "Return same error code until interval passes if table init is failed",
  NULL,
  NULL,
  1,
  0,
  4294967295U,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(uint, table_init_error_interval)

static int spider_use_table_charset;
/*
 -1 :fallback to default
  0 :use utf8
  1 :use table charset
 */
static MYSQL_SYSVAR_INT(
  use_table_charset,
  spider_use_table_charset,
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
  "Use table charset for remote access",
  NULL,
  spider_var_deprecated_int,
  1,
  -1,
  1,
  0
);

SPIDER_SYSVAR_OVERRIDE_VALUE_FUNC(int, use_table_charset)

/*
  0: no recycle
  1: recycle in instance
  2: recycle in thread
 */
static MYSQL_THDVAR_UINT(
  conn_recycle_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Connection recycle mode", /* comment */
  NULL, /* check */
  NULL, /* update */
  0, /* def */
  0, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(uint, conn_recycle_mode)

/*
  0: weak
  1: strict
 */
static MYSQL_THDVAR_UINT(
  conn_recycle_strict, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Strict connection recycle", /* comment */
  NULL, /* check */
  NULL, /* update */
  0, /* def */
  0, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(uint, conn_recycle_strict)

/*
  FALSE: no sync
  TRUE:  sync
 */
static MYSQL_THDVAR_BOOL(
  sync_trx_isolation, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Sync transaction isolation level", /* comment */
  NULL, /* check */
  NULL, /* update */
  TRUE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, sync_trx_isolation)

/*
  FALSE: no use
  TRUE:  use
 */
static MYSQL_THDVAR_BOOL(
  use_consistent_snapshot, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Use start transaction with consistent snapshot", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, use_consistent_snapshot)

/*
  FALSE: off
  TRUE:  on
 */
static MYSQL_THDVAR_BOOL(
  internal_xa, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Use inner xa transaction", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, internal_xa)

/*
  0 :err when use a spider table
  1 :err when start trx
  2 :start trx with snapshot on remote server(not use xa)
  3 :start xa on remote server(not use trx with snapshot)
 */
static MYSQL_THDVAR_UINT(
  internal_xa_snapshot, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Action of inner xa and snapshot both using", /* comment */
  NULL, /* check */
  NULL, /* update */
  0, /* def */
  0, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(uint, internal_xa_snapshot)

/*
  0 :off
  1 :continue prepare, commit, rollback if xid not found return
  2 :continue prepare, commit, rollback if all error return
 */
static MYSQL_THDVAR_UINT(
  force_commit, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Force prepare, commit, rollback mode", /* comment */
  NULL, /* check */
  NULL, /* update */
  1, /* def */
  0, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(uint, force_commit)

/*
  0: register all XA transaction
  1: register only write XA transaction
 */
static MYSQL_THDVAR_UINT(
  xa_register_mode, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Mode of XA transaction register into system table", /* comment */
  NULL, /* check */
  NULL, /* update */
  1, /* def */
  0, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(uint, xa_register_mode)

/*
 -1 :fallback to default
  0-:offset
 */
static MYSQL_THDVAR_LONGLONG(
  internal_offset, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Internal offset", /* comment */
  NULL, /* check */
  spider_var_deprecated_longlong, /* update */
  0, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, internal_offset)

/*
 -1 :fallback to default
  0-:limit
 */
static MYSQL_THDVAR_LONGLONG(
  internal_limit, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Internal limit", /* comment */
  NULL, /* check */
  spider_var_deprecated_longlong, /* update */
  9223372036854775807LL, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, internal_limit)

/*
 -1 :fallback to default
  0-:number of rows at a select
 */
static MYSQL_THDVAR_LONGLONG(
  split_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Number of rows at a select", /* comment */
  NULL, /* check */
  spider_var_deprecated_longlong, /* update */
  9223372036854775807LL, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, split_read)

/*
  -1 :fallback to default
   0 :doesn't use "offset" and "limit" for "split_read"
   1-:magnification
 */
static MYSQL_THDVAR_INT(
  semi_split_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Use offset and limit parameter in SQL for split_read parameter", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  2, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(double, semi_split_read)

/*
 -1 :fallback to default
  0-:the limit value
 */
static MYSQL_THDVAR_LONGLONG(
  semi_split_read_limit, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "The limit value for semi_split_read", /* comment */
  NULL, /* check */
  spider_var_deprecated_longlong, /* update */
  9223372036854775807LL, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, semi_split_read_limit)

/*
 -1 :fallback to default
  0 :no alloc
  1-:alloc size
 */
static MYSQL_THDVAR_INT(
  init_sql_alloc_size, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Initial sql string alloc size", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1024, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, init_sql_alloc_size)

/*
 -1 :fallback to default
  0 :off
  1 :on
 */
static MYSQL_THDVAR_INT(
  reset_sql_alloc, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Reset sql string alloc after execute", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, reset_sql_alloc)

/*
 -1 :fallback to default
  0 :off
  1 :on
 */
static MYSQL_THDVAR_INT(
  multi_split_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Split read mode for multi range", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  100, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, multi_split_read)

/*
 -1 :fallback to default
  0-:max order columns
 */
static MYSQL_THDVAR_INT(
  max_order, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Max columns for order by", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  32767, /* def */
  -1, /* min */
  32767, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, max_order)

/*
 -1 :off
  0 :read uncommitted
  1 :read committed
  2 :repeatable read
  3 :serializable
 */
static MYSQL_THDVAR_INT(
  semi_trx_isolation, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Transaction isolation level during execute a sql", /* comment */
  NULL, /* check */
  NULL, /* update */
  -1, /* def */
  -1, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(int, semi_trx_isolation)

static int spider_param_semi_table_lock_check(
  MYSQL_THD thd,
  struct st_mysql_sys_var *var,
  void *save,
  struct st_mysql_value *value
) {
  int error_num;
  SPIDER_TRX *trx;
  my_bool fixed;
  long long tmp;
  struct my_option options;
  DBUG_ENTER("spider_param_semi_table_lock_check");
  if (!(trx = spider_get_trx((THD *) thd, TRUE, &error_num)))
    DBUG_RETURN(error_num);
  if (trx->locked_connections)
  {
    my_message(ER_SPIDER_ALTER_BEFORE_UNLOCK_NUM,
      ER_SPIDER_ALTER_BEFORE_UNLOCK_STR, MYF(0));
    DBUG_RETURN(ER_SPIDER_ALTER_BEFORE_UNLOCK_NUM);
  }
  value->val_int(value, &tmp);
  options.deprecation_substitute = 0;
  options.var_type = GET_INT;
  options.def_value = ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->def_val;
  options.min_value = ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->min_val;
  options.max_value = ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->max_val;
  options.block_size =
    (long) ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->blk_sz;
  options.arg_type = REQUIRED_ARG;
  *((int *) save) = (int) getopt_ll_limit_value(tmp, &options, &fixed);
  DBUG_RETURN(throw_bounds_warning(thd,
    ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->name, fixed, FALSE,
    (longlong) tmp));
}

/*
  0 :off
  1 :on
 */
static MYSQL_THDVAR_INT(
  semi_table_lock, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Table lock during execute a sql", /* comment */
  &spider_param_semi_table_lock_check, /* check */
  NULL, /* update */
  0, /* def */
  0, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, semi_table_lock)

static int spider_param_semi_table_lock_connection_check(
  MYSQL_THD thd,
  struct st_mysql_sys_var *var,
  void *save,
  struct st_mysql_value *value
) {
  int error_num;
  SPIDER_TRX *trx;
  my_bool fixed;
  long long tmp;
  struct my_option options;
  DBUG_ENTER("spider_param_semi_table_lock_connection_check");
  if (!(trx = spider_get_trx((THD *) thd, TRUE, &error_num)))
    DBUG_RETURN(error_num);
  if (trx->locked_connections)
  {
    my_message(ER_SPIDER_ALTER_BEFORE_UNLOCK_NUM,
      ER_SPIDER_ALTER_BEFORE_UNLOCK_STR, MYF(0));
    DBUG_RETURN(ER_SPIDER_ALTER_BEFORE_UNLOCK_NUM);
  }
  value->val_int(value, &tmp);
  options.deprecation_substitute = 0;
  options.var_type = GET_INT;
  options.def_value = ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->def_val;
  options.min_value = ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->min_val;
  options.max_value = ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->max_val;
  options.block_size =
    (long) ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->blk_sz;
  options.arg_type = REQUIRED_ARG;
  *((int *) save) = (int) getopt_ll_limit_value(tmp, &options, &fixed);
  DBUG_RETURN(throw_bounds_warning(thd,
    ((MYSQL_SYSVAR_NAME(thdvar_int_t) *) var)->name, fixed, FALSE,
    (longlong) tmp));
}

/*
 -1 :off
  0 :use same connection
  1 :use different connection
 */
static MYSQL_THDVAR_INT(
  semi_table_lock_connection, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Use different connection if semi_table_lock is enabled", /* comment */
  &spider_param_semi_table_lock_connection_check, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, semi_table_lock_connection)

/*
  0-:block_size
 */
static MYSQL_THDVAR_UINT(
  block_size, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Index block size", /* comment */
  NULL, /* check */
  NULL, /* update */
  16384, /* def */
  0, /* min */
  4294967295U, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(uint, block_size)

/*
 -1 :fallback to default
  0 :off
  1 :lock in share mode
  2 :for update
 */
static MYSQL_THDVAR_INT(
  selupd_lock_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Lock for select with update", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, selupd_lock_mode)

/*
  FALSE: no sync
  TRUE:  sync
 */
static MYSQL_THDVAR_BOOL(
  sync_autocommit, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Sync autocommit", /* comment */
  NULL, /* check */
  NULL, /* update */
  TRUE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, sync_autocommit)

/*
  FALSE: not use
  TRUE:  use
 */
static MYSQL_THDVAR_BOOL(
  use_default_database, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Use default database", /* comment */
  NULL, /* check */
  NULL, /* update */
  TRUE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, use_default_database)

/*
-1 :don't know or does not matter; don't send 'SET SQL_LOG_OFF' statement
 0 :do send 'SET SQL_LOG_OFF 0' statement to data nodes
 1 :do send 'SET SQL_LOG_OFF 1' statement to data nodes
*/
static MYSQL_THDVAR_INT(
  internal_sql_log_off,                                  /* name */
  PLUGIN_VAR_RQCMDARG,                                   /* opt */
  "Manage SQL_LOG_OFF mode statement to the data nodes", /* comment */
  NULL,                                                  /* check */
  NULL,                                                  /* update */
  -1,                                                    /* default */
  -1,                                                    /* min */
  1,                                                     /* max */
  0                                                      /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(int, internal_sql_log_off)

/*
 -1 :fallback to default
  0-:bulk insert size
 */
static MYSQL_THDVAR_INT(
  bulk_size, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Bulk insert size", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  16000, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, bulk_size)

/*
 -1 :fallback to default
  0 : Send "update" and "delete" statements one by one.
  1 : Send collected multiple "update" and "delete" statements.
      (Collected statements are sent one by one)
  2 : Send collected multiple "update" and "delete" statements.
      (Collected statements are sent together)
 */
static MYSQL_THDVAR_INT(
  bulk_update_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "The mode of bulk updating and deleting", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, bulk_update_mode)

/*
 -1 :fallback to default
  0-:bulk update size
 */
static MYSQL_THDVAR_INT(
  bulk_update_size, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Bulk update size", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  16000, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, bulk_update_size)

/*
 -1 :fallback to default
  0-:buffer size
 */
static MYSQL_THDVAR_INT(
  buffer_size, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Buffer size", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  16000, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, buffer_size)

/*
 -1 :fallback to default
  0 :off
  1 :on
 */
static MYSQL_THDVAR_INT(
  internal_optimize, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Execute optimize to remote server", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, internal_optimize)

/*
 -1 :fallback to default
  0 :off
  1 :on
 */
static MYSQL_THDVAR_INT(
  internal_optimize_local, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Execute optimize to remote server with local", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, internal_optimize_local)

/*
  FALSE: off
  TRUE:  on
 */
static MYSQL_THDVAR_BOOL(
  use_flash_logs, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Execute flush logs to remote server", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, use_flash_logs)

/*
  0 :off
  1 :flush tables with read lock
  2 :flush tables another connection
 */
static MYSQL_THDVAR_INT(
  use_snapshot_with_flush_tables, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Execute optimize to remote server with local", /* comment */
  NULL, /* check */
  NULL, /* update */
  0, /* def */
  0, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(int, use_snapshot_with_flush_tables)

/*
  FALSE: off
  TRUE:  on
 */
static MYSQL_THDVAR_BOOL(
  use_all_conns_snapshot, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "When start trx with snapshot, it send to all connections", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, use_all_conns_snapshot)

/*
  FALSE: off
  TRUE:  on
 */
static MYSQL_THDVAR_BOOL(
  lock_exchange, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Exchange select lock to lock tables", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, lock_exchange)

/*
  FALSE: off
  TRUE:  on
 */
static MYSQL_THDVAR_BOOL(
  internal_unlock, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Unlock tables for using connections in sql", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, internal_unlock)

/*
  FALSE: off
  TRUE:  on
 */
static MYSQL_THDVAR_BOOL(
  semi_trx, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Take a transaction during execute a sql", /* comment */
  NULL, /* check */
  NULL, /* update */
  TRUE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, semi_trx)

/*
 -1 :fallback to default
  0-:seconds of timeout
 */
static MYSQL_THDVAR_INT(
  connect_timeout, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Wait timeout of connecting to remote server", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  6, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, connect_timeout)

/*
 -1 :fallback to default
  0-:seconds of timeout
 */
static MYSQL_THDVAR_INT(
  net_read_timeout, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Wait timeout of receiving data from remote server", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  600, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, net_read_timeout)

/*
 -1 :fallback to default
  0-:seconds of timeout
 */
static MYSQL_THDVAR_INT(
  net_write_timeout, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Wait timeout of sending data to remote server", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  600, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, net_write_timeout)

/*
 -1 :fallback to default
  0 :It acquires it collectively.
  1 :Acquisition one by one.If it discontinues once, and it will need
     it later, it retrieves it again when there is interrupt on the way.
  2 :Acquisition one by one.Interrupt is waited for until end of getting
     result when there is interrupt on the way.
 */
static MYSQL_THDVAR_INT(
  quick_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "The retrieval result from a remote server is acquired by acquisition one by one", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  3, /* def */
  -1, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, quick_mode)

/*
 -1 :fallback to default
  0-:number of records
 */
static MYSQL_THDVAR_LONGLONG(
  quick_page_size, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Number of records in a page when acquisition one by one", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1024, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, quick_page_size)

/*
 -1 :fallback to default
  0-:the limitation of memory size
 */
static MYSQL_THDVAR_LONGLONG(
  quick_page_byte, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "The limitation of memory size in a page when acquisition one by one", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  10485760, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, quick_page_byte)

/*
 -1 :fallback to default
  0 :It doesn't use low memory mode.
  1 :It uses low memory mode.
 */
static MYSQL_THDVAR_INT(
  low_mem_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Use low memory mode when SQL(SELECT) internally issued to a remote server is executed and get a result list", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, low_mem_read)

/*
 -1 :fallback to default
  0 :Use index columns if select statement can solve by using index,
     otherwise use all columns.
  1 :Use columns that are judged necessary.
 */
static MYSQL_THDVAR_INT(
  select_column_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "The mode of using columns at select clause", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, select_column_mode)

/*
 -1 :fallback to default
  0 :background search is disabled
  1 :background search is used if search with no lock
  2 :background search is used if search with no lock or shared lock
  3 :background search is used regardless of the lock
 */
static MYSQL_THDVAR_INT(
  bgs_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Mode of background search", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, bgs_mode)

/*
 -1 :fallback to default
  0 :records is gotten usually
  1-:number of records
 */
static MYSQL_THDVAR_LONGLONG(
  bgs_first_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Number of first read records when background search is used", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  2, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, bgs_first_read)

/*
 -1 :fallback to default
  0 :records is gotten usually
  1-:number of records
 */
static MYSQL_THDVAR_LONGLONG(
  bgs_second_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Number of second read records when background search is used", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  100, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, bgs_second_read)

/*
 -1 :fallback to default
  0 :records is gotten usually
  1-:number of records
 */
static MYSQL_THDVAR_LONGLONG(
  first_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Number of first read records", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, first_read)

/*
 -1 :fallback to default
  0 :records is gotten usually
  1-:number of records
 */
static MYSQL_THDVAR_LONGLONG(
  second_read, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Number of second read records", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, second_read)

/*
 -1 :fallback to default
  0 :always get the newest information
  1-:interval
 */
static MYSQL_THDVAR_INT(
  crd_interval, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Interval of cardinality confirmation.(second)", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  51, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(double, crd_interval)

/*
 -1 :fallback to default
  0 :use table parameter
  1 :use show command
  2 :use information schema
  3 :use explain
 */
static MYSQL_THDVAR_INT(
  crd_mode, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Mode of cardinality confirmation", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, crd_mode)

/*
 -1 :fallback to default
  0 :No synchronization.
  1 :Cardinality is synchronized when opening a table.
     Then no synchronization.
  2 :Synchronization.
 */
static MYSQL_THDVAR_INT(
  crd_sync, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Cardinality synchronization in partitioned table", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, crd_sync)

/*
 -1 :fallback to default
  0 :The crd_weight is used as a fixed value.
  1 :The crd_weight is used as an addition value.
  2 :The crd_weight is used as a multiplication value.
 */
static MYSQL_THDVAR_INT(
  crd_type, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Type of cardinality calculation", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  2, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, crd_type)

/*
 -1 :fallback to default
  0-:weight
 */
static MYSQL_THDVAR_INT(
  crd_weight, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Weight coefficient to calculate effectiveness of index from cardinality of column", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  2, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(double, crd_weight)

/*
 -1 :fallback to default
  0 :Background confirmation is disabled
  1 :Background confirmation is enabled (create thread per table/partition)
  2 :Background confirmation is enabled (use static threads)
 */
static MYSQL_THDVAR_INT(
  crd_bg_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Mode of cardinality confirmation at background", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  2, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, crd_bg_mode)

/*
 -1 :fallback to default
  0 :always get the newest information
  1-:interval
 */
static MYSQL_THDVAR_INT(
  sts_interval, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Interval of table state confirmation.(second)", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  10, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(double, sts_interval)

/*
 -1 :fallback to default
  0 :use table parameter
  1 :use show command
  2 :use information schema
 */
static MYSQL_THDVAR_INT(
  sts_mode, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Mode of table state confirmation", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, sts_mode)

/*
 -1 :fallback to default
  0 :No synchronization.
  1 :Table stat is synchronized when opening a table.
     Then no synchronization.
  2 :Synchronization.
 */
static MYSQL_THDVAR_INT(
  sts_sync, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Table state synchronization in partitioned table", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, sts_sync)

/*
 -1 :fallback to default
  0 :Background confirmation is disabled
  1 :Background confirmation is enabled (create thread per table/partition)
  2 :Background confirmation is enabled (use static threads)
 */
static MYSQL_THDVAR_INT(
  sts_bg_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Mode of table state confirmation at background", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  2, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, sts_bg_mode)

/*
  0 :always ping
  1-:interval
 */
static MYSQL_THDVAR_INT(
  ping_interval_at_trx_start, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Ping interval at transaction start", /* comment */
  NULL, /* check */
  NULL, /* update */
  3600, /* def */
  0, /* min */
  2147483647, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(double, ping_interval_at_trx_start)

/*
 -1 :fallback to default
  0 :normal mode
  1 :quick mode
  2 :set 0 value
 */
static MYSQL_THDVAR_INT(
  auto_increment_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Mode of auto increment", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, auto_increment_mode)

/*
  FALSE: off
  TRUE:  on
 */
static MYSQL_THDVAR_BOOL(
  same_server_link, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Permit one to link same server's table", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, same_server_link)

/*
  FALSE: transmits
  TRUE:  don't transmit
 */
static MYSQL_THDVAR_BOOL(
  local_lock_table, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Remote server transmission when lock tables is executed at local",
    /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, local_lock_table)

/*
 -1 :fallback to default
  0 :don't transmit
  1 :transmits
 */
static MYSQL_THDVAR_INT(
  use_pushdown_udf, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Remote server transmission existence when UDF is used at condition", /* comment */
  NULL, /* check */
  NULL, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, use_pushdown_udf)

/*
 -1 :fallback to default
  0 :duplicate check on local server
  1 :avoid duplicate check on local server
 */
static MYSQL_THDVAR_INT(
  direct_dup_insert, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Execute \"REPLACE\" and \"INSERT IGNORE\" on remote server and avoid duplicate check on local server", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, direct_dup_insert)

static char *spider_remote_access_charset;
/*
 */
static MYSQL_SYSVAR_STR(
  remote_access_charset,
  spider_remote_access_charset,
  PLUGIN_VAR_MEMALLOC |
  PLUGIN_VAR_RQCMDARG,
  "Set remote access charset at connecting for improvement performance of connection if you know",
  NULL,
  NULL,
  NULL
);

SPIDER_SYSVAR_VALUE_FUNC(char*, remote_access_charset)

static int spider_remote_autocommit;
/*
 -1 :don't set
  0 :autocommit = 0
  1 :autocommit = 1
 */
static MYSQL_SYSVAR_INT(
  remote_autocommit,
  spider_remote_autocommit,
  PLUGIN_VAR_RQCMDARG,
  "Set autocommit mode at connecting for improvement performance of connection if you know",
  NULL,
  NULL,
  -1,
  -1,
  1,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(int, remote_autocommit)

static char *spider_remote_time_zone;
/*
 */
static MYSQL_SYSVAR_STR(
  remote_time_zone,
  spider_remote_time_zone,
  PLUGIN_VAR_MEMALLOC |
  PLUGIN_VAR_RQCMDARG,
  "Set remote time_zone at connecting for improvement performance of connection if you know",
  NULL,
  NULL,
  NULL
);

SPIDER_SYSVAR_VALUE_FUNC(char *, remote_time_zone)

static int spider_remote_sql_log_off;
/*
 -1 :don't know the value on all data nodes, or does not matter
  0 :sql_log_off = 0 on all data nodes
  1 :sql_log_off = 1 on all data nodes
 */
static MYSQL_SYSVAR_INT(
  remote_sql_log_off,
  spider_remote_sql_log_off,
  PLUGIN_VAR_RQCMDARG,
  "Set SQL_LOG_OFF mode on connecting for improved performance of connection, if you know",
  NULL,
  NULL,
  -1,
  -1,
  1,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(int, remote_sql_log_off)

static int spider_remote_trx_isolation;
/*
 -1 :don't set
  0 :READ UNCOMMITTED
  1 :READ COMMITTED
  2 :REPEATABLE READ
  3 :SERIALIZABLE
 */
static MYSQL_SYSVAR_INT(
  remote_trx_isolation,
  spider_remote_trx_isolation,
  PLUGIN_VAR_RQCMDARG,
  "Set transaction isolation level at connecting for improvement performance of connection if you know",
  NULL,
  NULL,
  -1,
  -1,
  3,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(int, remote_trx_isolation)

static char *spider_remote_default_database;
/*
 */
static MYSQL_SYSVAR_STR(
  remote_default_database,
  spider_remote_default_database,
  PLUGIN_VAR_MEMALLOC |
  PLUGIN_VAR_RQCMDARG,
  "Set remote database at connecting for improvement performance of connection if you know",
  NULL,
  NULL,
  NULL
);

SPIDER_SYSVAR_VALUE_FUNC(char *, remote_default_database)

/*
  0-:connect retry interval (micro second)
 */
static MYSQL_THDVAR_LONGLONG(
  connect_retry_interval, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Connect retry interval", /* comment */
  NULL, /* check */
  NULL, /* update */
  1000, /* def */
  0, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

longlong spider_param_connect_retry_interval(
  THD *thd
) {
  DBUG_ENTER("spider_param_connect_retry_interval");
  if (thd)
    DBUG_RETURN(THDVAR(thd, connect_retry_interval));
  DBUG_RETURN(0);
}

/*
  0-:connect retry count
 */
static MYSQL_THDVAR_INT(
  connect_retry_count, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Connect retry count", /* comment */
  NULL, /* check */
  NULL, /* update */
  2, /* def */
  0, /* min */
  2147483647, /* max */
  0 /* blk */
);

int spider_param_connect_retry_count(
  THD *thd
) {
  DBUG_ENTER("spider_param_connect_retry_count");
  if (thd)
    DBUG_RETURN(THDVAR(thd, connect_retry_count));
  DBUG_RETURN(0);
}

/*
 */
static MYSQL_THDVAR_STR(
  bka_engine, /* name */
  PLUGIN_VAR_MEMALLOC |
  PLUGIN_VAR_RQCMDARG,
  "Temporary table's engine for BKA", /* comment */
  NULL, /* check */
  NULL, /* update */
  NULL /* def */
);

char *spider_param_bka_engine(
  THD *thd,
  char *bka_engine
) {
  DBUG_ENTER("spider_param_bka_engine");
  DBUG_RETURN(bka_engine ? bka_engine : THDVAR(thd, bka_engine));
}

/*
 -1 :fallback to default
  0 :use union all
  1 :use temporary table
 */
static MYSQL_THDVAR_INT(
  bka_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Mode of BKA for Spider", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  2, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, bka_mode)

/*
 -1 :fallback to default
  0 :return error if error
  1 :return 0 record if error
 */
static MYSQL_THDVAR_INT(
  error_read_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Read error mode if error", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, error_read_mode)

/*
 -1 :fallback to default
  0 :return error if error
  1 :return 0 record if error
 */
static MYSQL_THDVAR_INT(
  error_write_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Write error mode if error", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, error_write_mode)

/*
 -1 :fallback to default
  0 :not skip
  1 :skip
 */
static MYSQL_THDVAR_INT(
  skip_default_condition, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Skip generating internal default condition", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, skip_default_condition)

/*
 -1 :fallback to default
  0 :not skip
  1 :skip parallel search if query is not SELECT statement
  2 :skip parallel search if query has SQL_NO_CACHE
  3 :1+2
 */
static MYSQL_THDVAR_INT(
  skip_parallel_search, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Skip parallel search by specific conditions", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, skip_parallel_search)

/*
 -1 :fallback to default
  0 :not send directly
  1-:send directly
 */
static MYSQL_THDVAR_LONGLONG(
  direct_order_limit, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Send 'ORDER BY' and 'LIMIT' to remote server directly", /* comment */
  NULL, /* check */
  spider_var_deprecated_longlong, /* update */
  9223372036854775807LL, /* def */
  -1, /* min */
  9223372036854775807LL, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(longlong, direct_order_limit)

/*
 -1 :fallback to default
  0 :writable
  1 :read only
 */
static MYSQL_THDVAR_INT(
  read_only_mode, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Read only", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, read_only_mode)

static my_bool spider_general_log;
static MYSQL_SYSVAR_BOOL(
  general_log,
  spider_general_log,
  PLUGIN_VAR_OPCMDARG,
  "Log query to remote server in general log",
  NULL,
  NULL,
  FALSE
);

SPIDER_SYSVAR_VALUE_FUNC(my_bool, general_log)

/*
  FALSE: no pushdown hints
  TRUE:  pushdown hints
 */
static MYSQL_THDVAR_BOOL(
  index_hint_pushdown, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "switch to control if push down index hint, like force_index", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(my_bool, index_hint_pushdown)

static uint spider_max_connections;
static MYSQL_SYSVAR_UINT(
  max_connections,
  spider_max_connections,
  PLUGIN_VAR_RQCMDARG,
  "the values, as the max conncetion from spider to remote mysql. Default 0, mean unlimit the connections",
  NULL,
  NULL,
  0, /* def */
  0, /* min */
  99999, /* max */
  0 /* blk */
);

SPIDER_SYSVAR_VALUE_FUNC(uint, max_connections)

static uint spider_conn_wait_timeout;
static MYSQL_SYSVAR_UINT(
  conn_wait_timeout,
  spider_conn_wait_timeout,
  PLUGIN_VAR_RQCMDARG,
  "the values, as the max waiting time when spider get a remote conn",
  NULL,
  NULL,
  10, /* def */
  0, /* min */
  1000, /* max */
  0 /* blk */
);

SPIDER_SYSVAR_VALUE_FUNC(uint, conn_wait_timeout)

static uint spider_log_result_errors;
/*
  0: no log
  1: log error
  2: log warning summary
  3: log warning
  4: log info
 */
static MYSQL_SYSVAR_UINT(
  log_result_errors,
  spider_log_result_errors,
  PLUGIN_VAR_RQCMDARG,
  "Log error from remote server in error log",
  NULL,
  NULL,
  0,
  0,
  4,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(uint, log_result_errors)

static uint spider_log_result_error_with_sql;
/*
  0: no log
  1: log spider sql at logging result errors
  2: log user sql at logging result errors
  3: log both sql at logging result errors
 */
static MYSQL_SYSVAR_UINT(
  log_result_error_with_sql,
  spider_log_result_error_with_sql,
  PLUGIN_VAR_RQCMDARG,
  "Log sql at logging result errors",
  NULL,
  NULL,
  0,
  0,
  3,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(uint, log_result_error_with_sql)

/*
  0: server_id + thread_id
  1: server_id + thread_id + query_id
 */
static MYSQL_THDVAR_UINT(
  internal_xa_id_type, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "The type of internal_xa id", /* comment */
  NULL, /* check */
  NULL, /* update */
  0, /* def */
  0, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(uint, internal_xa_id_type)

/*
 -1 :fallback to default
  0 :OFF
  1 :automatic channel
  2-63 :use custom channel
 */
static MYSQL_THDVAR_INT(
  casual_read, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "Read casually if it is possible", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  63, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, casual_read)

static my_bool spider_dry_access;
static MYSQL_SYSVAR_BOOL(
  dry_access,
  spider_dry_access,
  PLUGIN_VAR_OPCMDARG | PLUGIN_VAR_READONLY,
  "dry access",
  NULL,
  NULL,
  FALSE
);

SPIDER_SYSVAR_VALUE_FUNC(my_bool, dry_access)

/*
 -1 :fallback to default
  0 :fast
  1 :correct delete row number
 */
static MYSQL_THDVAR_INT(
  delete_all_rows_type, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "The type of delete_all_rows", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, delete_all_rows_type)

/*
 -1 :fallback to default
  0 :compact
  1 :add original table name
 */
static MYSQL_THDVAR_INT(
  bka_table_name_type, /* name */
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED, /* opt */
  "The type of temporary table name for bka", /* comment */
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  0, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, bka_table_name_type)

/*
 -1 :fallback to default
  0 :off
  1 :on
 */
static MYSQL_THDVAR_INT(
  use_cond_other_than_pk_for_update, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Use all conditions even if condition has pk", /* comment */
  NULL, /* check */
  NULL, /* update */
  1, /* def */
  0, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_VALUE_FUNC(int, use_cond_other_than_pk_for_update)

static int spider_store_last_sts;
/*
 -1 : fallback to default
  0 : do not store
  1 : do store
 */
static MYSQL_SYSVAR_INT(
  store_last_sts,
  spider_store_last_sts,
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED,
  "Store last sts result into system table",
  NULL,
  spider_var_deprecated_int,
  1,
  -1,
  1,
  0
);

SPIDER_SYSVAR_OVERRIDE_VALUE_FUNC(int, store_last_sts)

static int spider_store_last_crd;
/*
 -1 : fallback to default
  0 : do not store
  1 : do store
 */
static MYSQL_SYSVAR_INT(
  store_last_crd,
  spider_store_last_crd,
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED,
  "Store last crd result into system table",
  NULL,
  spider_var_deprecated_int,
  1,
  -1,
  1,
  0
);

SPIDER_SYSVAR_OVERRIDE_VALUE_FUNC(int, store_last_crd)

static int spider_load_sts_at_startup;
/*
 -1 : fallback to default
  0 : do not load
  1 : do load
 */
static MYSQL_SYSVAR_INT(
  load_sts_at_startup,
  spider_load_sts_at_startup,
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED,
  "Load sts from system table at startup",
  NULL,
  spider_var_deprecated_int,
  1,
  -1,
  1,
  0
);

SPIDER_SYSVAR_OVERRIDE_VALUE_FUNC(int, load_sts_at_startup)

static int spider_load_crd_at_startup;
/*
 -1 : fallback to default
  0 : do not load
  1 : do load
 */
static MYSQL_SYSVAR_INT(
  load_crd_at_startup,
  spider_load_crd_at_startup,
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_DEPRECATED,
  "Load crd from system table at startup",
  NULL,
  spider_var_deprecated_int,
  1,
  -1,
  1,
  0
);

SPIDER_SYSVAR_OVERRIDE_VALUE_FUNC(int, load_crd_at_startup)

static uint spider_table_sts_thread_count;
/*
  1-: thread count
 */
static MYSQL_SYSVAR_UINT(
  table_sts_thread_count,
  spider_table_sts_thread_count,
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY | PLUGIN_VAR_DEPRECATED,
  "Deprecated parameter with no effect",
  NULL,
  NULL,
  1,
  1,
  4294967295U,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(uint, table_sts_thread_count)

static uint spider_table_crd_thread_count;
/*
  1-: thread count
 */
static MYSQL_SYSVAR_UINT(
  table_crd_thread_count,
  spider_table_crd_thread_count,
  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY | PLUGIN_VAR_DEPRECATED,
  "Deprecated parameter with no effect",
  NULL,
  NULL,
  1,
  1,
  4294967295U,
  0
);

SPIDER_SYSVAR_VALUE_FUNC(uint, table_crd_thread_count)

static int spider_slave_trx_isolation;
/*
 -1 :off
  0 :read uncommitted
  1 :read committed
  2 :repeatable read
  3 :serializable
 */
static MYSQL_SYSVAR_INT(
  slave_trx_isolation,
  spider_slave_trx_isolation,
  PLUGIN_VAR_RQCMDARG,
  "Transaction isolation level when Spider table is used by slave SQL thread",
  NULL, /* check */
  NULL, /* update */
  -1, /* def */
  -1, /* min */
  3, /* max */
  0 /* blk */
);

SPIDER_SYSVAR_VALUE_FUNC(int, slave_trx_isolation)

/*
 -1 :not set
  0-:seconds of timeout
 */
static MYSQL_THDVAR_INT(
  remote_wait_timeout, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Wait timeout on remote server", /* comment */
  NULL, /* check */
  NULL, /* update */
  -1, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

int spider_param_remote_wait_timeout(
  THD *thd
) {
  DBUG_ENTER("spider_param_remote_wait_timeout");
  if (likely(thd))
    DBUG_RETURN(THDVAR(thd, remote_wait_timeout));
  DBUG_RETURN(-1);
}

/*
 -1 :not set
  0-:seconds of timeout
 */
static MYSQL_THDVAR_INT(
  wait_timeout, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Wait timeout of setting to remote server", /* comment */
  NULL, /* check */
  NULL, /* update */
  604800, /* def */
  -1, /* min */
  2147483647, /* max */
  0 /* blk */
);

int spider_param_wait_timeout(
  THD *thd
) {
  DBUG_ENTER("spider_param_wait_timeout");
  if (likely(thd))
    DBUG_RETURN(THDVAR(thd, wait_timeout));
  DBUG_RETURN(604800);
}

/*
  FALSE: no sync
  TRUE:  sync
 */
static MYSQL_THDVAR_BOOL(
  sync_sql_mode, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Sync sql_mode", /* comment */
  NULL, /* check */
  NULL, /* update */
  TRUE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, sync_sql_mode)

/*
 -1 : fallback to default
  0 : do not strict
  1 : do strict
 */
static MYSQL_THDVAR_INT(
  strict_group_by, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Use columns in select clause strictly for group by clause",
  NULL, /* check */
  spider_var_deprecated_int, /* update */
  1, /* def */
  -1, /* min */
  1, /* max */
  0 /* blk */
);

SPIDER_THDVAR_OVERRIDE_VALUE_FUNC(int, strict_group_by)

/*
 -1 : use table parameter
  0 : do not strict
  1 : do strict
 */
static MYSQL_THDVAR_BOOL(
  direct_aggregate, /* name */
  PLUGIN_VAR_RQCMDARG, /* opt */
  "Whether to enable direct aggregate",
  NULL, /* check */
  NULL, /* update */
  TRUE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, direct_aggregate)

static MYSQL_THDVAR_BOOL(
  disable_group_by_handler, /* name */
  PLUGIN_VAR_OPCMDARG, /* opt */
  "Disables the group by handler", /* comment */
  NULL, /* check */
  NULL, /* update */
  FALSE /* def */
);

SPIDER_THDVAR_VALUE_FUNC(bool, disable_group_by_handler)

static MYSQL_THDVAR_BOOL(
  suppress_comment_ignored_warning,
  PLUGIN_VAR_RQCMDARG,
  "Whether to suppress warnings that table COMMENT or CONNECTION strings "
  "are ignored due to specified table options",
  NULL,
  NULL,
  FALSE
);

SPIDER_THDVAR_VALUE_FUNC(bool, suppress_comment_ignored_warning)

static MYSQL_THDVAR_BOOL(
  ignore_comments,
  PLUGIN_VAR_RQCMDARG,
  "Whether to unconditionally ignore COMMENT and CONNECTION strings "
  "without checking whether table options are specified",
  NULL,
  NULL,
  FALSE
);

SPIDER_THDVAR_VALUE_FUNC(bool, ignore_comments)

static struct st_mysql_storage_engine spider_storage_engine =
{ MYSQL_HANDLERTON_INTERFACE_VERSION };

static struct st_mysql_sys_var* spider_system_variables[] = {
  MYSQL_SYSVAR(support_xa),
  MYSQL_SYSVAR(table_init_error_interval),
  MYSQL_SYSVAR(use_table_charset),
  MYSQL_SYSVAR(conn_recycle_mode),
  MYSQL_SYSVAR(conn_recycle_strict),
  MYSQL_SYSVAR(sync_trx_isolation),
  MYSQL_SYSVAR(use_consistent_snapshot),
  MYSQL_SYSVAR(internal_xa),
  MYSQL_SYSVAR(internal_xa_snapshot),
  MYSQL_SYSVAR(force_commit),
  MYSQL_SYSVAR(xa_register_mode),
  MYSQL_SYSVAR(internal_offset),
  MYSQL_SYSVAR(internal_limit),
  MYSQL_SYSVAR(split_read),
  MYSQL_SYSVAR(semi_split_read),
  MYSQL_SYSVAR(semi_split_read_limit),
  MYSQL_SYSVAR(init_sql_alloc_size),
  MYSQL_SYSVAR(reset_sql_alloc),
  MYSQL_SYSVAR(multi_split_read),
  MYSQL_SYSVAR(max_order),
  MYSQL_SYSVAR(semi_trx_isolation),
  MYSQL_SYSVAR(semi_table_lock),
  MYSQL_SYSVAR(semi_table_lock_connection),
  MYSQL_SYSVAR(block_size),
  MYSQL_SYSVAR(selupd_lock_mode),
  MYSQL_SYSVAR(sync_autocommit),
  MYSQL_SYSVAR(use_default_database),
  MYSQL_SYSVAR(internal_sql_log_off),
  MYSQL_SYSVAR(bulk_size),
  MYSQL_SYSVAR(bulk_update_mode),
  MYSQL_SYSVAR(bulk_update_size),
  MYSQL_SYSVAR(buffer_size),
  MYSQL_SYSVAR(internal_optimize),
  MYSQL_SYSVAR(internal_optimize_local),
  MYSQL_SYSVAR(use_flash_logs),
  MYSQL_SYSVAR(use_snapshot_with_flush_tables),
  MYSQL_SYSVAR(use_all_conns_snapshot),
  MYSQL_SYSVAR(lock_exchange),
  MYSQL_SYSVAR(internal_unlock),
  MYSQL_SYSVAR(semi_trx),
  MYSQL_SYSVAR(connect_timeout),
  MYSQL_SYSVAR(net_read_timeout),
  MYSQL_SYSVAR(net_write_timeout),
  MYSQL_SYSVAR(quick_mode),
  MYSQL_SYSVAR(quick_page_size),
  MYSQL_SYSVAR(quick_page_byte),
  MYSQL_SYSVAR(low_mem_read),
  MYSQL_SYSVAR(select_column_mode),
  MYSQL_SYSVAR(bgs_mode),
  MYSQL_SYSVAR(bgs_first_read),
  MYSQL_SYSVAR(bgs_second_read),
  MYSQL_SYSVAR(first_read),
  MYSQL_SYSVAR(second_read),
  MYSQL_SYSVAR(crd_interval),
  MYSQL_SYSVAR(crd_mode),
  MYSQL_SYSVAR(crd_sync),
  MYSQL_SYSVAR(store_last_crd),
  MYSQL_SYSVAR(load_crd_at_startup),
  MYSQL_SYSVAR(crd_type),
  MYSQL_SYSVAR(crd_weight),
  MYSQL_SYSVAR(crd_bg_mode),
  MYSQL_SYSVAR(sts_interval),
  MYSQL_SYSVAR(sts_mode),
  MYSQL_SYSVAR(sts_sync),
  MYSQL_SYSVAR(store_last_sts),
  MYSQL_SYSVAR(load_sts_at_startup),
  MYSQL_SYSVAR(sts_bg_mode),
  MYSQL_SYSVAR(ping_interval_at_trx_start),
  MYSQL_SYSVAR(auto_increment_mode),
  MYSQL_SYSVAR(same_server_link),
  MYSQL_SYSVAR(local_lock_table),
  MYSQL_SYSVAR(use_pushdown_udf),
  MYSQL_SYSVAR(direct_dup_insert),
  MYSQL_SYSVAR(remote_access_charset),
  MYSQL_SYSVAR(remote_autocommit),
  MYSQL_SYSVAR(remote_time_zone),
  MYSQL_SYSVAR(remote_sql_log_off),
  MYSQL_SYSVAR(remote_trx_isolation),
  MYSQL_SYSVAR(remote_default_database),
  MYSQL_SYSVAR(connect_retry_interval),
  MYSQL_SYSVAR(connect_retry_count),
  MYSQL_SYSVAR(connect_mutex),
  MYSQL_SYSVAR(bka_engine),
  MYSQL_SYSVAR(bka_mode),
  MYSQL_SYSVAR(error_read_mode),
  MYSQL_SYSVAR(error_write_mode),
  MYSQL_SYSVAR(skip_default_condition),
  MYSQL_SYSVAR(skip_parallel_search),
  MYSQL_SYSVAR(direct_order_limit),
  MYSQL_SYSVAR(read_only_mode),
  MYSQL_SYSVAR(general_log),
  MYSQL_SYSVAR(index_hint_pushdown),
  MYSQL_SYSVAR(max_connections),
  MYSQL_SYSVAR(conn_wait_timeout),
  MYSQL_SYSVAR(log_result_errors),
  MYSQL_SYSVAR(log_result_error_with_sql),
  MYSQL_SYSVAR(internal_xa_id_type),
  MYSQL_SYSVAR(casual_read),
  MYSQL_SYSVAR(dry_access),
  MYSQL_SYSVAR(delete_all_rows_type),
  MYSQL_SYSVAR(bka_table_name_type),
  MYSQL_SYSVAR(use_cond_other_than_pk_for_update),
  MYSQL_SYSVAR(connect_error_interval),
  MYSQL_SYSVAR(table_sts_thread_count),
  MYSQL_SYSVAR(table_crd_thread_count),
  MYSQL_SYSVAR(slave_trx_isolation),
  MYSQL_SYSVAR(remote_wait_timeout),
  MYSQL_SYSVAR(wait_timeout),
  MYSQL_SYSVAR(sync_sql_mode),
  MYSQL_SYSVAR(strict_group_by),
  MYSQL_SYSVAR(direct_aggregate),
  MYSQL_SYSVAR(disable_group_by_handler),
  MYSQL_SYSVAR(suppress_comment_ignored_warning),
  MYSQL_SYSVAR(ignore_comments),
  NULL
};

mysql_declare_plugin(spider)
{
  MYSQL_STORAGE_ENGINE_PLUGIN,
  &spider_storage_engine,
  "SPIDER",
  "Kentoku Shiba",
  "Spider storage engine",
  PLUGIN_LICENSE_GPL,
  spider_db_init,
  spider_db_done,
  SPIDER_HEX_VERSION,
  spider_status_variables,
  spider_system_variables,
  NULL,
  0,
},
spider_i_s_alloc_mem,
spider_i_s_wrapper_protocols
mysql_declare_plugin_end;

maria_declare_plugin(spider)
{
  MYSQL_STORAGE_ENGINE_PLUGIN,
  &spider_storage_engine,
  "SPIDER",
  "Kentoku Shiba",
  "Spider storage engine",
  PLUGIN_LICENSE_GPL,
  spider_db_init,
  spider_db_done,
  SPIDER_HEX_VERSION,
  spider_status_variables,
  spider_system_variables,
  SPIDER_DETAIL_VERSION,
  MariaDB_PLUGIN_MATURITY_STABLE
},
spider_i_s_alloc_mem_maria,
spider_i_s_wrapper_protocols_maria
maria_declare_plugin_end;
