1 /***************************************************************************** 2 3 Copyright (c) 2009, 2018, Oracle and/or its affiliates. All Rights Reserved. 4 5 This program is free software; you can redistribute it and/or modify it under 6 the terms of the GNU General Public License, version 2.0, as published by the 7 Free Software Foundation. 8 9 This program is also distributed with certain software (including but not 10 limited to OpenSSL) that is licensed under separate terms, as designated in a 11 particular file or component or in included license documentation. The authors 12 of MySQL hereby grant you an additional permission to link the program and 13 your derivative works with the separately licensed software that they have 14 included with MySQL. 15 16 This program is distributed in the hope that it will be useful, but WITHOUT 17 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 18 FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, 19 for more details. 20 21 You should have received a copy of the GNU General Public License along with 22 this program; if not, write to the Free Software Foundation, Inc., 23 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 24 25 *****************************************************************************/ 26 27 /** @file include/dict0stats.h 28 Code used for calculating and manipulating table statistics. 29 30 Created Jan 06, 2010 Vasil Dimov 31 *******************************************************/ 32 33 #ifndef dict0stats_h 34 #define dict0stats_h 35 36 #include "univ.i" 37 38 #include "dict0types.h" 39 #include "mem0mem.h" 40 #include "trx0types.h" 41 42 enum dict_stats_upd_option_t { 43 DICT_STATS_RECALC_PERSISTENT, /* (re) calculate the 44 statistics using a precise and slow 45 algo and save them to the persistent 46 storage, if the persistent storage is 47 not present then emit a warning and 48 fall back to transient stats */ 49 DICT_STATS_RECALC_TRANSIENT, /* (re) calculate the statistics 50 using an imprecise quick algo 51 without saving the results 52 persistently */ 53 DICT_STATS_EMPTY_TABLE, /* Write all zeros (or 1 where it makes sense) 54 into a table and its indexes' statistics 55 members. The resulting stats correspond to an 56 empty table. If the table is using persistent 57 statistics, then they are saved on disk. */ 58 DICT_STATS_FETCH_ONLY_IF_NOT_IN_MEMORY /* fetch the stats 59 from the persistent storage if the in-memory 60 structures have not been initialized yet, 61 otherwise do nothing */ 62 }; 63 64 /** Set the persistent statistics flag for a given table. This is set only in 65 the in-memory table object and is not saved on disk. It will be read from the 66 .frm file upon first open from MySQL after a server restart. 67 @param[in,out] table table 68 @param[in] ps_on persistent stats explicitly enabled 69 @param[in] ps_off persistent stats explicitly disabled */ 70 UNIV_INLINE 71 void dict_stats_set_persistent(dict_table_t *table, ibool ps_on, ibool ps_off); 72 73 /** Check whether persistent statistics is enabled for a given table. 74 @return true if enabled, false otherwise */ 75 UNIV_INLINE 76 ibool dict_stats_is_persistent_enabled( 77 const dict_table_t *table) /*!< in: table */ 78 MY_ATTRIBUTE((warn_unused_result)); 79 80 /** Set the auto recalc flag for a given table (only honored for a persistent 81 stats enabled table). The flag is set only in the in-memory table object and is 82 not saved in InnoDB files. It will be read from the .frm file upon first open 83 from MySQL after a server restart. 84 @param[in,out] table table 85 @param[in] auto_recalc_on explicitly enabled 86 @param[in] auto_recalc_off explicitly disabled */ 87 UNIV_INLINE 88 void dict_stats_auto_recalc_set(dict_table_t *table, ibool auto_recalc_on, 89 ibool auto_recalc_off); 90 91 /** Check whether auto recalc is enabled for a given table. 92 @return true if enabled, false otherwise */ 93 UNIV_INLINE 94 ibool dict_stats_auto_recalc_is_enabled( 95 const dict_table_t *table); /*!< in: table */ 96 97 /** Initialize table's stats for the first time when opening a table. */ 98 UNIV_INLINE 99 void dict_stats_init(dict_table_t *table); /*!< in/out: table */ 100 101 /** Deinitialize table's stats after the last close of the table. This is 102 used to detect "FLUSH TABLE" and refresh the stats upon next open. */ 103 UNIV_INLINE 104 void dict_stats_deinit(dict_table_t *table); /*!< in/out: table */ 105 106 /** Calculates new estimates for table and index statistics. The statistics 107 are used in query optimization. 108 @return DB_* error code or DB_SUCCESS */ 109 dberr_t dict_stats_update(dict_table_t *table, /*!< in/out: table */ 110 dict_stats_upd_option_t stats_upd_option); 111 /*!< in: whether to (re) calc 112 the stats or to fetch them from 113 the persistent storage */ 114 115 /** Removes the information for a particular index's stats from the persistent 116 storage if it exists and if there is data stored for this index. 117 This function creates its own trx and commits it. 118 @return DB_SUCCESS or error code */ 119 dberr_t dict_stats_drop_index( 120 const char *tname, /*!< in: table name */ 121 const char *iname, /*!< in: index name */ 122 char *errstr, /*!< out: error message if != DB_SUCCESS 123 is returned */ 124 ulint errstr_sz); /*!< in: size of the errstr buffer */ 125 126 /** Removes the statistics for a table and all of its indexes from the 127 persistent storage if it exists and if there is data stored for the table. 128 This function creates its own transaction and commits it. 129 @return DB_SUCCESS or error code */ 130 dberr_t dict_stats_drop_table( 131 const char *table_name, /*!< in: table name */ 132 char *errstr, /*!< out: error message 133 if != DB_SUCCESS is returned */ 134 ulint errstr_sz); /*!< in: size of errstr buffer */ 135 136 /** Fetches or calculates new estimates for index statistics. */ 137 void dict_stats_update_for_index(dict_index_t *index); /*!< in/out: index */ 138 139 /** Renames a table in InnoDB persistent stats storage. 140 This function creates its own transaction and commits it. 141 @return DB_SUCCESS or error code */ 142 dberr_t dict_stats_rename_table(const char *old_name, /*!< in: old table name */ 143 const char *new_name, /*!< in: new table name */ 144 char *errstr, /*!< out: error string if != 145 DB_SUCCESS is returned */ 146 size_t errstr_sz); /*!< in: errstr size */ 147 148 /** Renames an index in InnoDB persistent stats storage. 149 This function creates its own transaction and commits it. 150 @return DB_SUCCESS or error code. DB_STATS_DO_NOT_EXIST will be returned 151 if the persistent stats do not exist. */ 152 dberr_t dict_stats_rename_index( 153 const dict_table_t *table, /*!< in: table whose index 154 is renamed */ 155 const char *old_index_name, /*!< in: old index name */ 156 const char *new_index_name) /*!< in: new index name */ 157 MY_ATTRIBUTE((warn_unused_result)); 158 159 /** Evict the stats tables if they loaded in tablespace cache and also 160 close the stats .ibd files. We have to close stats tables because 161 8.0 stats tables will use the same name. We load the stats from 5.7 162 with a suffix "_backup57" and migrate the statistics. */ 163 void dict_stats_evict_tablespaces(); 164 165 /** Represent the record of innodb_table_stats table. */ 166 class TableStatsRecord { 167 public: 168 /** Constructor. */ 169 TableStatsRecord(); 170 171 /** Destructor. */ 172 ~TableStatsRecord(); 173 174 /** Set the data for the innodb_table_stats record. 175 @param[in] data data to be set in the record 176 @param[in] col_offset column offset 177 @param[in] len length of the data. */ 178 void set_data(const byte *data, ulint col_offset, ulint len); 179 180 /** Get the table name from innodb_table_stats record. 181 @retval table name of the table_stats record. */ 182 char *get_tbl_name() const; 183 184 /** Set the table name for the innodb_table_stats record. 185 @param[in] data data to be set in the record 186 @param[in] len length of the data. */ 187 void set_tbl_name(const byte *data, ulint len); 188 189 /** Get the db name from the innodb_table_stats record. 190 @retval db name of the table stats record. */ 191 char *get_db_name() const; 192 193 /** Set the db name for the innodb_table_stats record. 194 @param[in] data data to be set 195 @param[in] len length of the data. */ 196 void set_db_name(const byte *data, ulint len); 197 198 /** Get the n_rows from the innodb_table_stats record. 199 @retval n_rows from the record. */ 200 ib_uint64_t get_n_rows() const; 201 202 /** Set the n_rows for the innodb_table_stats record. 203 @param[in] no_of_rows number of rows. */ 204 void set_n_rows(ib_uint64_t no_of_rows); 205 206 /** Get the clustered index size from 207 innodb_table_stats record. 208 @retval size of the clustered index. */ 209 ulint get_clustered_index_size() const; 210 211 /** Set the clustered index size for the 212 innodb_table_stats record. 213 @param[in] clust_size clustered index size. */ 214 void set_clustered_index_size(ulint clust_size); 215 216 /** Get the sum of other index size. 217 @retval sum of secondary index size. */ 218 ulint get_sum_of_other_index_size() const; 219 220 /** Set the sum of sec index size. 221 @param[in] sum_of_other_index_size sum of secondary index size. */ 222 void set_sum_of_other_index_size(ulint sum_of_other_index_size); 223 224 /** Column number of innodb_table_stats.database_name. */ 225 static constexpr unsigned DB_NAME_COL_NO = 0; 226 /** Column number of innodb_table_stats.table_name. */ 227 static constexpr unsigned TABLE_NAME_COL_NO = 1; 228 /** Column number of innodb_table_stats.n_rows. */ 229 static constexpr unsigned N_ROWS_COL_NO = 3; 230 /** Column number of innodb_table_stats.clustered_index_size. */ 231 static constexpr unsigned CLUST_INDEX_SIZE_COL_NO = 4; 232 /** Column number of innodb_table_stats.sum_of_other_index_sizes. */ 233 static constexpr unsigned SUM_OF_OTHER_INDEX_SIZE_COL_NO = 5; 234 235 private: 236 /** Database name. */ 237 char *m_db_name; 238 /** Table name. */ 239 char *m_tbl_name; 240 /** Number of rows. */ 241 ib_uint64_t m_n_rows; 242 /** Clustered index size. */ 243 ulint m_clustered_index_size; 244 /** Sum of other index size. */ 245 ulint m_sum_of_other_index_sizes; 246 /** Heap to store db_name, tbl_name for the record. */ 247 mem_heap_t *m_heap; 248 }; 249 250 /** Calculates new estimates for table and index statistics. This function 251 is relatively quick and is used to calculate transient statistics that 252 are not saved on disk. 253 This was the only way to calculate statistics before the 254 Persistent Statistics feature was introduced. */ 255 void dict_stats_update_transient(dict_table_t *table); /*!< in/out: table */ 256 257 #include "dict0stats.ic" 258 259 #ifdef UNIV_ENABLE_UNIT_TEST_DICT_STATS 260 void test_dict_stats_all(); 261 #endif /* UNIV_ENABLE_UNIT_TEST_DICT_STATS */ 262 263 #endif /* dict0stats_h */ 264