ACIL FM

Nama	Ukuran	Aksi
atomic	-	Open
data	-	Open
providers	-	Open
aligned.h	1.11 MB	View DL Edit
aria_backup.h	1.51 MB	View DL Edit
assume_aligned.h	2.29 MB	View DL Edit
authors.h	9.9 MB	View DL Edit
backup.h	1.66 MB	View DL Edit
bounded_queue.h	5.95 MB	View DL Edit
charset_collations.h	6.41 MB	View DL Edit
char_buffer.h	3.09 MB	View DL Edit
client_settings.h	1.87 MB	View DL Edit
compat56.h	2.23 MB	View DL Edit
config.h	14.21 MB	View DL Edit
contributors.h	4.76 MB	View DL Edit
create_options.h	4.09 MB	View DL Edit
create_tmp_table.h	2.74 MB	View DL Edit
cset_narrowing.h	3.88 MB	View DL Edit
custom_conf.h	1.06 MB	View DL Edit
datadict.h	1.66 MB	View DL Edit
ddl_log.h	12.51 MB	View DL Edit
debug.h	1.26 MB	View DL Edit
debug_sync.h	2 MB	View DL Edit
deprecation.h	2.74 MB	View DL Edit
derived_handler.h	2.32 MB	View DL Edit
derror.h	980 B	View DL Edit
des_key_file.h	1.21 MB	View DL Edit
discover.h	1.53 MB	View DL Edit
dur_prop.h	1.06 MB	View DL Edit
embedded_priv.h	1.69 MB	View DL Edit
events.h	4.6 MB	View DL Edit
event_data_objects.h	4.09 MB	View DL Edit
event_db_repository.h	3.56 MB	View DL Edit
event_parse_data.h	2.83 MB	View DL Edit
event_queue.h	3.36 MB	View DL Edit
event_scheduler.h	3.21 MB	View DL Edit
field.h	217.81 MB	View DL Edit
field_comp.h	1.15 MB	View DL Edit
filesort.h	7.13 MB	View DL Edit
filesort_utils.h	10.53 MB	View DL Edit
ft_global.h	3.04 MB	View DL Edit
gcalc_slicescan.h	16.87 MB	View DL Edit
gcalc_tools.h	11.62 MB	View DL Edit
grant.h	2.69 MB	View DL Edit
group_by_handler.h	3.45 MB	View DL Edit
gstream.h	2.38 MB	View DL Edit
gtid_index.h	19.54 MB	View DL Edit
handler.h	206.19 MB	View DL Edit
handle_connections_win.h	884 B	View DL Edit
hash.h	4.35 MB	View DL Edit
hash_filo.h	5.55 MB	View DL Edit
ha_handler_stats.h	2.28 MB	View DL Edit
ha_partition.h	63.36 MB	View DL Edit
ha_sequence.h	6.1 MB	View DL Edit
heap.h	9.26 MB	View DL Edit
hostname.h	5.29 MB	View DL Edit
ilist.h	6.98 MB	View DL Edit
init.h	852 B	View DL Edit
innodb_priv.h	1.29 MB	View DL Edit
item.h	276.43 MB	View DL Edit
item_cmpfunc.h	132.01 MB	View DL Edit
item_create.h	11.24 MB	View DL Edit
item_func.h	134.64 MB	View DL Edit
item_geofunc.h	38.16 MB	View DL Edit
item_jsonfunc.h	27.86 MB	View DL Edit
item_row.h	5.1 MB	View DL Edit
item_strfunc.h	75.33 MB	View DL Edit
item_subselect.h	57.63 MB	View DL Edit
item_sum.h	70.69 MB	View DL Edit
item_timefunc.h	63.85 MB	View DL Edit
item_vers.h	4.26 MB	View DL Edit
item_windowfunc.h	33.56 MB	View DL Edit
item_xmlfunc.h	4.52 MB	View DL Edit
json_schema.h	25.1 MB	View DL Edit
json_schema_helper.h	1.13 MB	View DL Edit
json_table.h	9.44 MB	View DL Edit
key.h	2.08 MB	View DL Edit
keycaches.h	1.94 MB	View DL Edit
lex.h	29.54 MB	View DL Edit
lex_charset.h	25.92 MB	View DL Edit
lex_hash.h	141.94 MB	View DL Edit
lex_ident.h	5.15 MB	View DL Edit
lex_string.h	4.77 MB	View DL Edit
lex_symbol.h	1.29 MB	View DL Edit
lex_token.h	42.01 MB	View DL Edit
lf.h	6.31 MB	View DL Edit
lock.h	2.2 MB	View DL Edit
log.h	51.28 MB	View DL Edit
log_cache.h	7.57 MB	View DL Edit
log_event.h	172.56 MB	View DL Edit
log_event_data_type.h	1.85 MB	View DL Edit
log_slow.h	2.38 MB	View DL Edit
maria.h	5.73 MB	View DL Edit
mariadb.h	1.25 MB	View DL Edit
mdl.h	37.65 MB	View DL Edit
mem_root_array.h	6.94 MB	View DL Edit
message.h	1.17 MB	View DL Edit
multi_range_read.h	22.65 MB	View DL Edit
myisam.h	17.18 MB	View DL Edit
myisamchk.h	4.62 MB	View DL Edit
myisammrg.h	4.78 MB	View DL Edit
myisampack.h	14.58 MB	View DL Edit
mysqld.h	41.11 MB	View DL Edit
mysqld_default_groups.h	204 B	View DL Edit
mysqld_suffix.h	1.17 MB	View DL Edit
mysys_err.h	2.99 MB	View DL Edit
my_apc.h	4.64 MB	View DL Edit
my_atomic.h	7.11 MB	View DL Edit
my_atomic_wrapper.h	2.98 MB	View DL Edit
my_base.h	27.28 MB	View DL Edit
my_bit.h	6.05 MB	View DL Edit
my_bitmap.h	5.37 MB	View DL Edit
my_check_opt.h	2.56 MB	View DL Edit
my_compare.h	10.87 MB	View DL Edit
my_counter.h	1.68 MB	View DL Edit
my_cpu.h	4.74 MB	View DL Edit
my_crypt.h	904 B	View DL Edit
my_decimal.h	14.15 MB	View DL Edit
my_default.h	1.84 MB	View DL Edit
my_handler_errors.h	4.77 MB	View DL Edit
my_json_writer.h	18.14 MB	View DL Edit
my_libwrap.h	1.16 MB	View DL Edit
my_md5.h	1.45 MB	View DL Edit
my_minidump.h	848 B	View DL Edit
my_nosys.h	1.4 MB	View DL Edit
my_rdtsc.h	9.88 MB	View DL Edit
my_rnd.h	1014 B	View DL Edit
my_service_manager.h	2.07 MB	View DL Edit
my_stacktrace.h	3.14 MB	View DL Edit
my_stack_alloc.h	6.34 MB	View DL Edit
my_time.h	10.17 MB	View DL Edit
my_tracker.h	1.37 MB	View DL Edit
my_tree.h	3.9 MB	View DL Edit
my_uctype.h	67.9 MB	View DL Edit
my_user.h	1.1 MB	View DL Edit
my_virtual_mem.h	1.1 MB	View DL Edit
optimizer_costs.h	5.89 MB	View DL Edit
optimizer_defaults.h	7.37 MB	View DL Edit
opt_histogram_json.h	4.71 MB	View DL Edit
opt_range.h	64.78 MB	View DL Edit
opt_rewrite_date_cmp.h	3.84 MB	View DL Edit
opt_subselect.h	14.78 MB	View DL Edit
opt_trace.h	8.29 MB	View DL Edit
opt_trace_context.h	3.21 MB	View DL Edit
parse_file.h	4.28 MB	View DL Edit
partition_element.h	5.3 MB	View DL Edit
partition_info.h	19.4 MB	View DL Edit
password.h	1.14 MB	View DL Edit
pfs_file_provider.h	3.08 MB	View DL Edit
pfs_idle_provider.h	1.35 MB	View DL Edit
pfs_memory_provider.h	1.59 MB	View DL Edit
pfs_metadata_provider.h	1.85 MB	View DL Edit
pfs_socket_provider.h	2.21 MB	View DL Edit
pfs_stage_provider.h	1.52 MB	View DL Edit
pfs_statement_provider.h	4.25 MB	View DL Edit
pfs_table_provider.h	2.56 MB	View DL Edit
pfs_thread_provider.h	5.43 MB	View DL Edit
pfs_transaction_provider.h	2.78 MB	View DL Edit
privilege.h	28.44 MB	View DL Edit
probes_mysql.h	973 B	View DL Edit
probes_mysql_dtrace.h	32.19 MB	View DL Edit
probes_mysql_nodtrace.h	5.94 MB	View DL Edit
procedure.h	6.63 MB	View DL Edit
protocol.h	12.27 MB	View DL Edit
proxy_protocol.h	548 B	View DL Edit
queues.h	3.4 MB	View DL Edit
records.h	3.07 MB	View DL Edit
replication.h	15.2 MB	View DL Edit
repl_failsafe.h	1.55 MB	View DL Edit
rijndael.h	1.67 MB	View DL Edit
rowid_filter.h	16.03 MB	View DL Edit
rpl_constants.h	3.28 MB	View DL Edit
rpl_filter.h	4.66 MB	View DL Edit
rpl_gtid.h	29.95 MB	View DL Edit
rpl_injector.h	9.4 MB	View DL Edit
rpl_mi.h	16.29 MB	View DL Edit
rpl_parallel.h	17.8 MB	View DL Edit
rpl_record.h	1.49 MB	View DL Edit
rpl_reporting.h	3.63 MB	View DL Edit
rpl_rli.h	35.02 MB	View DL Edit
rpl_tblmap.h	3.1 MB	View DL Edit
rpl_utility.h	10.93 MB	View DL Edit
scheduler.h	3.12 MB	View DL Edit
scope.h	4.29 MB	View DL Edit
select_handler.h	3.34 MB	View DL Edit
semisync.h	2.23 MB	View DL Edit
semisync_master.h	25.16 MB	View DL Edit
semisync_master_ack_receiver.h	8.5 MB	View DL Edit
semisync_slave.h	3.65 MB	View DL Edit
service_versions.h	2.23 MB	View DL Edit
session_tracker.h	13.75 MB	View DL Edit
set_var.h	16.39 MB	View DL Edit
simple_tokenizer.h	1.97 MB	View DL Edit
slave.h	11.99 MB	View DL Edit
socketpair.h	842 B	View DL Edit
source_revision.h	67 B	View DL Edit
sp.h	23.11 MB	View DL Edit
span.h	3.84 MB	View DL Edit
spatial.h	21.78 MB	View DL Edit
sp_cache.h	1.99 MB	View DL Edit
sp_head.h	38.61 MB	View DL Edit
sp_instr.h	40.41 MB	View DL Edit
sp_pcontext.h	24.71 MB	View DL Edit
sp_rcontext.h	14.08 MB	View DL Edit
sql_acl.h	13.75 MB	View DL Edit
sql_admin.h	2.85 MB	View DL Edit
sql_alloc.h	1.69 MB	View DL Edit
sql_alter.h	15.08 MB	View DL Edit
sql_analyse.h	10.86 MB	View DL Edit
sql_analyze_stmt.h	12.4 MB	View DL Edit
sql_array.h	6.97 MB	View DL Edit
sql_audit.h	13.83 MB	View DL Edit
sql_base.h	25.87 MB	View DL Edit
sql_basic_types.h	9.3 MB	View DL Edit
sql_binlog.h	895 B	View DL Edit
sql_bitmap.h	7.88 MB	View DL Edit
sql_bootstrap.h	1.77 MB	View DL Edit
sql_cache.h	21.34 MB	View DL Edit
sql_callback.h	1.51 MB	View DL Edit
sql_class.h	270.56 MB	View DL Edit
sql_cmd.h	15.11 MB	View DL Edit
sql_connect.h	3.96 MB	View DL Edit
sql_const.h	10.07 MB	View DL Edit
sql_crypt.h	1.4 MB	View DL Edit
sql_cte.h	16.15 MB	View DL Edit
sql_cursor.h	4.14 MB	View DL Edit
sql_db.h	2.28 MB	View DL Edit
sql_debug.h	5.51 MB	View DL Edit
sql_delete.h	3.52 MB	View DL Edit
sql_derived.h	1.26 MB	View DL Edit
sql_digest.h	3.73 MB	View DL Edit
sql_digest_stream.h	1.53 MB	View DL Edit
sql_do.h	954 B	View DL Edit
sql_error.h	39.39 MB	View DL Edit
sql_explain.h	30.39 MB	View DL Edit
sql_expression_cache.h	4.26 MB	View DL Edit
sql_get_diagnostics.h	7.7 MB	View DL Edit
sql_handler.h	2.84 MB	View DL Edit
sql_help.h	995 B	View DL Edit
sql_hset.h	3.32 MB	View DL Edit
sql_insert.h	5.05 MB	View DL Edit
sql_i_s.h	8.29 MB	View DL Edit
sql_join_cache.h	47.52 MB	View DL Edit
sql_lex.h	174.22 MB	View DL Edit
sql_lifo_buffer.h	9.45 MB	View DL Edit
sql_limit.h	3.11 MB	View DL Edit
sql_list.h	21.87 MB	View DL Edit
sql_load.h	1.25 MB	View DL Edit
sql_locale.h	3.16 MB	View DL Edit
sql_manager.h	960 B	View DL Edit
sql_mode.h	6.58 MB	View DL Edit
sql_parse.h	8.31 MB	View DL Edit
sql_partition.h	12.38 MB	View DL Edit
sql_partition_admin.h	5.8 MB	View DL Edit
sql_plist.h	7.53 MB	View DL Edit
sql_plugin.h	7.4 MB	View DL Edit
sql_plugin_compat.h	2.18 MB	View DL Edit
sql_prepare.h	11.4 MB	View DL Edit
sql_priv.h	15.08 MB	View DL Edit
sql_profile.h	7.63 MB	View DL Edit
sql_reload.h	1.01 MB	View DL Edit
sql_rename.h	982 B	View DL Edit
sql_repl.h	2.99 MB	View DL Edit
sql_schema.h	3.23 MB	View DL Edit
sql_select.h	91 MB	View DL Edit
sql_sequence.h	5.06 MB	View DL Edit
sql_servers.h	1.74 MB	View DL Edit
sql_show.h	9.73 MB	View DL Edit
sql_signal.h	3.28 MB	View DL Edit
sql_sort.h	21.96 MB	View DL Edit
sql_statistics.h	16.41 MB	View DL Edit
sql_string.h	37.92 MB	View DL Edit
sql_table.h	9.52 MB	View DL Edit
sql_test.h	1.55 MB	View DL Edit
sql_time.h	7.24 MB	View DL Edit
sql_trigger.h	11.88 MB	View DL Edit
sql_truncate.h	2.03 MB	View DL Edit
sql_tvc.h	2.36 MB	View DL Edit
sql_type.h	291.25 MB	View DL Edit
sql_type_fixedbin.h	63.94 MB	View DL Edit
sql_type_fixedbin_storage.h	5.34 MB	View DL Edit
sql_type_geom.h	18.59 MB	View DL Edit
sql_type_int.h	9.77 MB	View DL Edit
sql_type_json.h	6.01 MB	View DL Edit
sql_type_real.h	1.23 MB	View DL Edit
sql_type_string.h	1.59 MB	View DL Edit
sql_type_timeofday.h	2.26 MB	View DL Edit
sql_udf.h	4.74 MB	View DL Edit
sql_union.h	1.04 MB	View DL Edit
sql_update.h	3.55 MB	View DL Edit
sql_used.h	1.02 MB	View DL Edit
sql_view.h	2.41 MB	View DL Edit
sql_window.h	6.65 MB	View DL Edit
ssl_compat.h	3.3 MB	View DL Edit
strfunc.h	2.22 MB	View DL Edit
structs.h	30.55 MB	View DL Edit
sys_vars_shared.h	2.67 MB	View DL Edit
table.h	118.11 MB	View DL Edit
table_cache.h	4.13 MB	View DL Edit
threadpool.h	4.7 MB	View DL Edit
threadpool_generic.h	3.88 MB	View DL Edit
threadpool_winsockets.h	2.24 MB	View DL Edit
thread_cache.h	5.77 MB	View DL Edit
thr_lock.h	7.06 MB	View DL Edit
thr_malloc.h	1.17 MB	View DL Edit
thr_timer.h	1.53 MB	View DL Edit
transaction.h	1.43 MB	View DL Edit
tzfile.h	4.9 MB	View DL Edit
tztime.h	3.65 MB	View DL Edit
t_ctype.h	5.51 MB	View DL Edit
uniques.h	4.13 MB	View DL Edit
unireg.h	7.76 MB	View DL Edit
vers_string.h	2.39 MB	View DL Edit
violite.h	9.85 MB	View DL Edit
waiting_threads.h	4.43 MB	View DL Edit
welcome_copyright_notice.h	1.42 MB	View DL Edit
winservice.h	5.88 MB	View DL Edit
wqueue.h	1.53 MB	View DL Edit
wsrep.h	3.23 MB	View DL Edit
wsrep_allowlist_service.h	1.01 MB	View DL Edit
wsrep_applier.h	2.64 MB	View DL Edit
wsrep_binlog.h	3.36 MB	View DL Edit
wsrep_client_service.h	2.5 MB	View DL Edit
wsrep_client_state.h	1.53 MB	View DL Edit
wsrep_condition_variable.h	1.45 MB	View DL Edit
wsrep_event_service.h	1.32 MB	View DL Edit
wsrep_high_priority_service.h	4.8 MB	View DL Edit
wsrep_mutex.h	1.21 MB	View DL Edit
wsrep_mysqld.h	20.93 MB	View DL Edit
wsrep_mysqld_c.h	1.2 MB	View DL Edit
wsrep_on.h	1.68 MB	View DL Edit
wsrep_plugin.h	1.35 MB	View DL Edit
wsrep_priv.h	1.6 MB	View DL Edit
wsrep_schema.h	5.48 MB	View DL Edit
wsrep_server_service.h	3.55 MB	View DL Edit
wsrep_server_state.h	3.06 MB	View DL Edit
wsrep_sst.h	3.86 MB	View DL Edit
wsrep_status.h	1.93 MB	View DL Edit
wsrep_storage_service.h	1.77 MB	View DL Edit
wsrep_thd.h	10.9 MB	View DL Edit
wsrep_trans_observer.h	17.75 MB	View DL Edit
wsrep_types.h	1.08 MB	View DL Edit
wsrep_utils.h	9.58 MB	View DL Edit
wsrep_var.h	4.25 MB	View DL Edit
wsrep_xid.h	1.51 MB	View DL Edit
xa.h	1.86 MB	View DL Edit

Edit file: /usr/include/mysql/server/private/sql_statistics.h

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  02110-1335  USA */

#ifndef SQL_STATISTICS_H
#define SQL_STATISTICS_H

#include <vector>
#include <string>

/*
  For COMPLEMENTARY_FOR_QUERIES and PREFERABLY_FOR_QUERIES they are
  similar to the COMPLEMENTARY and PREFERABLY respectively except that
  with these values we would not be collecting EITS for queries like
    ANALYZE TABLE t1;
  To collect EITS with these values, we have to use PERSISITENT FOR
  analyze table t1 persistent for
     columns (col1,col2...) index (idx1, idx2...)
     or
  analyze table t1 persistent for all
*/

typedef
enum enum_use_stat_tables_mode
{
  NEVER,
  COMPLEMENTARY,
  PREFERABLY,
  COMPLEMENTARY_FOR_QUERIES,
  PREFERABLY_FOR_QUERIES
} Use_stat_tables_mode;

typedef
enum enum_histogram_type
{
  SINGLE_PREC_HB,
  DOUBLE_PREC_HB,
  JSON_HB,
  INVALID_HISTOGRAM
} Histogram_type;

enum enum_stat_tables
{
  TABLE_STAT,
  COLUMN_STAT,
  INDEX_STAT,
};

/* 
  These enumeration types comprise the dictionary of three
  statistical tables table_stat, column_stat and index_stat
  as they defined in ../scripts/mysql_system_tables.sql.

It would be nice if the declarations of these types were
  generated automatically by the table definitions.   
*/

enum enum_table_stat_col
{
  TABLE_STAT_DB_NAME,
  TABLE_STAT_TABLE_NAME,
  TABLE_STAT_CARDINALITY,
  TABLE_STAT_N_FIELDS
};

enum enum_column_stat_col
{
  COLUMN_STAT_DB_NAME,
  COLUMN_STAT_TABLE_NAME,
  COLUMN_STAT_COLUMN_NAME,
  COLUMN_STAT_MIN_VALUE,
  COLUMN_STAT_MAX_VALUE,
  COLUMN_STAT_NULLS_RATIO,
  COLUMN_STAT_AVG_LENGTH,
  COLUMN_STAT_AVG_FREQUENCY,
  COLUMN_STAT_HIST_SIZE,
  COLUMN_STAT_HIST_TYPE,
  COLUMN_STAT_HISTOGRAM,
  COLUMN_STAT_N_FIELDS
};

enum enum_index_stat_col
{
  INDEX_STAT_DB_NAME,
  INDEX_STAT_TABLE_NAME,
  INDEX_STAT_INDEX_NAME,
  INDEX_STAT_PREFIX_ARITY,
  INDEX_STAT_AVG_FREQUENCY,
  INDEX_STAT_N_FIELDS
};

inline
Use_stat_tables_mode get_use_stat_tables_mode(THD *thd)
{ 
  return (Use_stat_tables_mode) (thd->variables.use_stat_tables);
}
inline
bool check_eits_collection_allowed(THD *thd)
{
  return (get_use_stat_tables_mode(thd) == COMPLEMENTARY ||
          get_use_stat_tables_mode(thd) == PREFERABLY);
}

inline
bool check_eits_preferred(THD *thd)
{
  return (get_use_stat_tables_mode(thd) == PREFERABLY ||
          get_use_stat_tables_mode(thd) == PREFERABLY_FOR_QUERIES);
}

int read_statistics_for_tables_if_needed(THD *thd, TABLE_LIST *tables);
int read_statistics_for_tables(THD *thd, TABLE_LIST *tables,
                               bool force_reload);
int collect_statistics_for_table(THD *thd, TABLE *table);
int alloc_statistics_for_table(THD *thd, TABLE *table, MY_BITMAP *stat_fields);
void free_statistics_for_table(TABLE *table);
int update_statistics_for_table(THD *thd, TABLE *table);
int delete_statistics_for_table(THD *thd, const LEX_CSTRING *db,
                                const LEX_CSTRING *tab);
int delete_statistics_for_column(THD *thd, TABLE *tab, Field *col);
int delete_statistics_for_index(THD *thd, TABLE *tab, KEY *key_info,
                                bool ext_prefixes_only);
int rename_table_in_stat_tables(THD *thd, const LEX_CSTRING *db,
                                const LEX_CSTRING *tab,
                                const LEX_CSTRING *new_db,
                                const LEX_CSTRING *new_tab);
int rename_columns_in_stat_table(THD *thd, TABLE *tab,
                                 List<Alter_info::RENAME_COLUMN_STAT_PARAMS> *fields);
int rename_indexes_in_stat_table(THD *thd, TABLE *tab,
                                 List<Alter_info::RENAME_INDEX_STAT_PARAMS> *indexes);
void set_statistics_for_table(THD *thd, TABLE *table);

double get_column_avg_frequency(Field * field);

double get_column_range_cardinality(Field *field,
                                    key_range *min_endp,
                                    key_range *max_endp,
                                    uint range_flag);
bool is_stat_table(const LEX_CSTRING *db, LEX_CSTRING *table);
bool is_eits_usable(Field* field);

class Histogram_builder;

/*
  Common base for all histograms
*/
class Histogram_base :public Sql_alloc
{
public:
  Histogram_base() {}
  virtual ~Histogram_base()= default;

virtual bool parse(MEM_ROOT *mem_root,
                     const char *db_name, const char *table_name,
                     Field *field, const char *hist_data,
                     size_t hist_data_len)= 0;
  virtual void serialize(Field *to_field)= 0;

virtual Histogram_type get_type()=0;

virtual uint get_width()=0;

/*
    The creation-time workflow is:
     * create a histogram
     * init_for_collection()
     * create_builder()
     * feed the data to the builder
     * serialize();
  */
  virtual void init_for_collection(MEM_ROOT *mem_root, Histogram_type htype_arg,
                                   ulonglong size)=0;
  virtual Histogram_builder *create_builder(Field *col, uint col_len,
                                            ha_rows rows)=0;

/*
    This function checks that histograms should be usable only when
      1) the level of optimizer_use_condition_selectivity > 3
  */
  bool is_usable(THD *thd)
  {
    return thd->variables.optimizer_use_condition_selectivity > 3;
  }

virtual double point_selectivity(Field *field, key_range *endpoint,
                                   double avg_sel)=0;
  virtual double range_selectivity(Field *field, key_range *min_endp,
                                   key_range *max_endp, double avg_sel)=0;
  /*
    Legacy: return the size of the histogram on disk.

This will be stored in mysql.column_stats.hist_size column.
    The value is not really needed as one can look at
    LENGTH(mysql.column_stats.histogram) directly.
  */
  virtual uint get_size()=0;
};

/*
  A Height-balanced histogram that stores numeric fractions
*/

class Histogram_binary final : public Histogram_base
{
private:
  Histogram_type type;
  size_t size; /* Size of values array, in bytes */
  uchar *values;

uint prec_factor()
  {
    switch (type) {
    case SINGLE_PREC_HB:
      return ((uint) (1 << 8) - 1);
    case DOUBLE_PREC_HB:
      return ((uint) (1 << 16) - 1);
    default:
      DBUG_ASSERT(0);
    }
    return 1;
  }

public:
  Histogram_binary(Histogram_type type_arg) : type(type_arg)
  {}

uint get_width() override
  {
    switch (type) {
    case SINGLE_PREC_HB:
      return (uint) size;
    case DOUBLE_PREC_HB:
      return (uint) (size / 2);
    default:
      DBUG_ASSERT(0);
    }
    return 0;
  }
private:
  uint get_value(uint i)
  {
    DBUG_ASSERT(i < get_width());
    switch (type) {
    case SINGLE_PREC_HB:
      return (uint) (((uint8 *) values)[i]);
    case DOUBLE_PREC_HB:
      return (uint) uint2korr(values + i * 2);
    default:
      DBUG_ASSERT(0);
    }
    return 0;
  }

/* Find the bucket which value 'pos' falls into. */
  uint find_bucket(double pos, bool first)
  {
    size_t val= (size_t) (pos * prec_factor());
    int lp= 0;
    int rp= get_width() - 1;
    int d= get_width() / 2;
    uint i= lp + d;
    for ( ; d;  d= (rp - lp) / 2, i= lp + d)
    {
      if (val == get_value(i))
	break; 
      if (val < get_value(i))
        rp= i;
      else if (val > get_value(i + 1))
        lp= i + 1;
      else
        break;
    }

if (val > get_value(i) && i < (get_width() - 1))
      i++;

if (val == get_value(i))
    {
      if (first)
      {
        while(i && val == get_value(i - 1))
          i--;
      }
      else
      {
        while(i + 1 < get_width() && val == get_value(i + 1))
          i++;
      }
    }
    return i;
  }

public:
  uint get_size() override {return (uint)size;}

Histogram_type get_type() override { return type; }

bool parse(MEM_ROOT *mem_root, const char*, const char*, Field*,
             const char *hist_data, size_t hist_data_len) override;
  void serialize(Field *to_field) override;
  void init_for_collection(MEM_ROOT *mem_root, Histogram_type htype_arg,
                           ulonglong size) override;
  Histogram_builder *create_builder(Field *col, uint col_len,
                                    ha_rows rows) override;

void set_value(uint i, double val)
  {
    switch (type) {
    case SINGLE_PREC_HB:
      ((uint8 *) values)[i]= (uint8) (val * prec_factor());
      return;
    case DOUBLE_PREC_HB:
      int2store(values + i * 2, val * prec_factor());
      return;
    default:
      DBUG_ASSERT(0);
      return;
    }
  }

void set_prev_value(uint i)
  {
    switch (type) {
    case SINGLE_PREC_HB:
      ((uint8 *) values)[i]= ((uint8 *) values)[i-1];
      return;
    case DOUBLE_PREC_HB:
      int2store(values + i * 2, uint2korr(values + i * 2 - 2));
      return;
    default:
      DBUG_ASSERT(0);
      return;
    }
  }

double range_selectivity(Field *field, key_range *min_endp,
                           key_range *max_endp, double avg_sel) override;

/*
    Estimate selectivity of "col=const" using a histogram
  */
  double point_selectivity(Field *field, key_range *endpoint,
                           double avg_sel) override;
};

/*
  This is used to collect the basic statistics from a Unique object:
   - count of values
   - count of distinct values
   - count of distinct values that have occurred only once
*/

class Basic_stats_collector
{
  ulonglong count;         /* number of values retrieved                   */
  ulonglong count_distinct;    /* number of distinct values retrieved      */
  /* number of distinct values that occurred only once  */
  ulonglong count_distinct_single_occurence;

public:
  Basic_stats_collector()
  {
    count= 0;
    count_distinct= 0;
    count_distinct_single_occurence= 0;
  }

ulonglong get_count_distinct() const { return count_distinct; }
  ulonglong get_count_single_occurence() const
  {
    return count_distinct_single_occurence;
  }
  ulonglong get_count() const { return count; }

void next(void *elem, element_count elem_cnt)
  {
    count_distinct++;
    if (elem_cnt == 1)
      count_distinct_single_occurence++;
    count+= elem_cnt;
  }
};

/*
  Histogram_builder is a helper class that is used to build histograms
  for columns.

Do not create directly, call Histogram->get_builder(...);
*/

class Histogram_builder: public Sql_alloc
{
protected:
  Field *column;           /* table field for which the histogram is built */
  uint col_length;         /* size of this field                           */
  ha_rows records;         /* number of records the histogram is built for */

Histogram_builder(Field *col, uint col_len, ha_rows rows) :
    column(col), col_length(col_len), records(rows)
  {}

public:
  // A histogram builder will also collect the counters
  Basic_stats_collector counters;

virtual int next(void *elem, element_count elem_cnt)=0;
  virtual void finalize()=0;
  virtual ~Histogram_builder(){}
};

class Column_statistics;
class Index_statistics;

/* Statistical data on a table */

class Table_statistics
{
public:
  my_bool cardinality_is_null;      /* TRUE if the cardinality is unknown */
  uint  columns;                    /* Number of columns in table */
  ha_rows cardinality;              /* Number of rows in the table        */
  uchar *min_max_record_buffers;    /* Record buffers for min/max values  */
  Column_statistics *column_stats;  /* Array of statistical data for columns */
  Index_statistics *index_stats;    /* Array of statistical data for indexes */

/* Array of records per key for index prefixes */
  ulonglong *idx_avg_frequency;
  uchar *histograms;                /* Sequence of histograms */
};

/* 
  Statistical data on a column

Note: objects of this class may be "empty", where they have almost all fields
  as zeros, for example, get_avg_frequency() will return 0.

objects are allocated in alloc_statistics_for_table[_share].
*/

class Column_statistics :public Sql_alloc
{

private:
  static const uint Scale_factor_nulls_ratio= 100000;
  static const uint Scale_factor_avg_length= 100000;
  static const uint Scale_factor_avg_frequency= 100000;

public:
  ~Column_statistics()
  {
    delete histogram;
  }
  /* 
    Bitmap indicating  what statistical characteristics
    are available for the column
  */
  uint32 column_stat_nulls;
  
  /* For the below two, see comments in get_column_range_cardinality() */
  /* Minimum value for the column */
  Field *min_value; 
  /* Maximum value for the column */   
  Field *max_value;

private:

/* 
    The ratio Z/N multiplied by the scale factor Scale_factor_nulls_ratio,
    where 
      N is the total number of rows,
      Z is the number of nulls in the column
  */
  ulong nulls_ratio;
 
  /*
    Average number of bytes occupied by the representation of a
    value of the column in memory buffers such as join buffer
    multiplied by the scale factor Scale_factor_avg_length.
    CHAR values are stripped of trailing spaces.
    Flexible values are stripped of their length prefixes.
  */
  ulonglong avg_length;

/*
    The ratio N/D multiplied by the scale factor Scale_factor_avg_frequency,
    where
       N is the number of rows with not null value in the column,
       D the number of distinct values among them
  */
  ulonglong avg_frequency;

public:
  Histogram_base *histogram;
  bool histogram_exists;

uint32 no_values_provided_bitmap()
  {
    return
     ((1 << (COLUMN_STAT_HISTOGRAM-COLUMN_STAT_COLUMN_NAME))-1) <<
      (COLUMN_STAT_COLUMN_NAME+1);
  }
 
  void set_all_nulls()
  {
    column_stat_nulls= no_values_provided_bitmap();
  }

void set_not_null(uint stat_field_no)
  {
    column_stat_nulls&= ~(1 << stat_field_no);
  }

void set_null(uint stat_field_no)
  {
    column_stat_nulls|= (1 << stat_field_no);
  }

bool is_null(uint stat_field_no)
  {
    return MY_TEST(column_stat_nulls & (1 << stat_field_no));
  }

double get_nulls_ratio()
  {
    return (double) nulls_ratio /  Scale_factor_nulls_ratio;
  }

double get_avg_length()
  {
    return (double) avg_length / Scale_factor_avg_length;
  }

double get_avg_frequency()
  {
    return (double) avg_frequency / Scale_factor_avg_frequency;
  }

void set_nulls_ratio (double val)
  {
    nulls_ratio= (ulong) (val * Scale_factor_nulls_ratio);
  }

void set_avg_length (double val)
  {
    avg_length= (ulonglong) (val * Scale_factor_avg_length);
  }

void set_avg_frequency (double val)
  {
    avg_frequency= (ulonglong) (val * Scale_factor_avg_frequency);
  }

bool min_max_values_are_provided()
  {
    return !is_null(COLUMN_STAT_MIN_VALUE) && 
      !is_null(COLUMN_STAT_MAX_VALUE);
  }
  /*
    This function checks whether the values for the fields of the statistical
    tables that were NULL by DEFAULT for a column have changed or not.

@retval
    TRUE: Statistics are not present for a column
    FALSE: Statisitics are present for a column
  */
  bool no_stat_values_provided()
  {
    return (column_stat_nulls == no_values_provided_bitmap());
  }
};

/* Statistical data on an index prefixes */

class Index_statistics
{

private:
  static const uint Scale_factor_avg_frequency= 100000;
  /*
    The k-th element of this array contains the ratio N/D
    multiplied by the scale factor Scale_factor_avg_frequency, 
    where N is the number of index entries without nulls 
    in the first k components, and D is the number of distinct
    k-component prefixes among them 
  */
  ulonglong *avg_frequency;
  bool stats_were_read;

public:
  void init_avg_frequency(ulonglong *ptr)
  {
    avg_frequency= ptr;
    stats_were_read= false;
  }

void mark_stats_as_read() { stats_were_read= true; }

bool has_stats(THD *thd) const
  {
    if (TEST_NEW_MODE_FLAG(thd, NEW_MODE_FIX_INDEX_STATS_FOR_ALL_NULLS))
      return stats_were_read;
    else
      return get_avg_frequency(0) > 0.5;
  }

bool avg_frequency_is_inited() { return avg_frequency != NULL; }

double get_avg_frequency(uint i) const
  {
    return (double) avg_frequency[i] / Scale_factor_avg_frequency;
  }

void set_avg_frequency(uint i, double val)
  {
    avg_frequency[i]= (ulonglong) (val * Scale_factor_avg_frequency);
  }

};

#endif /* SQL_STATISTICS_H */

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