1 /* Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved. 2 3 This program is free software; you can redistribute it and/or modify 4 it under the terms of the GNU General Public License as published by 5 the Free Software Foundation; version 2 of the License. 6 7 This program is distributed in the hope that it will be useful, 8 but WITHOUT ANY WARRANTY; without even the implied warranty of 9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 GNU General Public License for more details. 11 12 You should have received a copy of the GNU General Public License 13 along with this program; if not, write to the Free Software 14 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ 15 16 /** 17 @file 18 File containing constants that can be used throughout the server. 19 20 @note This file shall not contain or include any declarations of any kinds. 21 */ 22 23 #ifndef SQL_CONST_INCLUDED 24 #define SQL_CONST_INCLUDED 25 26 #include <mysql_version.h> 27 28 #define LIBLEN FN_REFLEN-FN_LEN /* Max l{ngd p} dev */ 29 /* extra 4+4 bytes for slave tmp tables */ 30 #define MAX_DBKEY_LENGTH (NAME_LEN*2+1+1+4+4) 31 #define MAX_ALIAS_NAME 256 32 #define MAX_FIELD_NAME 34 /* Max colum name length +2 */ 33 #define MAX_SYS_VAR_LENGTH 32 34 #define MAX_KEY MAX_INDEXES /* Max used keys */ 35 #define MAX_REF_PARTS 32 /* Max parts used as ref */ 36 37 /* 38 Maximum length of the data part of an index lookup key. 39 40 The "data part" is defined as the value itself, not including the 41 NULL-indicator bytes or varchar length bytes ("the Extras"). We need this 42 value because there was a bug where length of the Extras were not counted. 43 44 You probably need MAX_KEY_LENGTH, not this constant. 45 */ 46 #define MAX_DATA_LENGTH_FOR_KEY 3072 47 #if SIZEOF_OFF_T > 4 48 #define MAX_REFLENGTH 8 /* Max length for record ref */ 49 #else 50 #define MAX_REFLENGTH 4 /* Max length for record ref */ 51 #endif 52 #define MAX_HOSTNAME 61 /* len+1 in mysql.user */ 53 #define MAX_CONNECTION_NAME NAME_LEN 54 55 #define MAX_MBWIDTH 3 /* Max multibyte sequence */ 56 #define MAX_FILENAME_MBWIDTH 5 57 #define MAX_FIELD_CHARLENGTH 255 58 /* 59 In MAX_FIELD_VARCHARLENGTH we reserve extra bytes for the overhead: 60 - 2 bytes for the length 61 - 1 byte for NULL bits 62 to avoid the "Row size too large" error for these three corner definitions: 63 CREATE TABLE t1 (c VARBINARY(65533)); 64 CREATE TABLE t1 (c VARBINARY(65534)); 65 CREATE TABLE t1 (c VARBINARY(65535)); 66 Like VARCHAR(65536), they will be converted to BLOB automatically 67 in non-strict mode. 68 */ 69 #define MAX_FIELD_VARCHARLENGTH (65535-2-1) 70 #define MAX_FIELD_BLOBLENGTH UINT_MAX32 /* cf field_blob::get_length() */ 71 #define CONVERT_IF_BIGGER_TO_BLOB 512 /* Threshold *in characters* */ 72 73 /* Max column width +1 */ 74 #define MAX_FIELD_WIDTH (MAX_FIELD_CHARLENGTH*MAX_MBWIDTH+1) 75 76 #define MAX_BIT_FIELD_LENGTH 64 /* Max length in bits for bit fields */ 77 78 #define MAX_DATE_WIDTH 10 /* YYYY-MM-DD */ 79 #define MIN_TIME_WIDTH 10 /* -HHH:MM:SS */ 80 #define MAX_TIME_WIDTH 16 /* -DDDDDD HH:MM:SS */ 81 #define MAX_TIME_FULL_WIDTH 23 /* -DDDDDD HH:MM:SS.###### */ 82 #define MAX_DATETIME_FULL_WIDTH 26 /* YYYY-MM-DD HH:MM:SS.###### */ 83 #define MAX_DATETIME_WIDTH 19 /* YYYY-MM-DD HH:MM:SS */ 84 #define MAX_DATETIME_COMPRESSED_WIDTH 14 /* YYYYMMDDHHMMSS */ 85 #define MAX_DATETIME_PRECISION 6 86 87 #define MAX_TABLES (sizeof(table_map)*8-3) /* Max tables in join */ 88 #define PARAM_TABLE_BIT (((table_map) 1) << (sizeof(table_map)*8-3)) 89 #define OUTER_REF_TABLE_BIT (((table_map) 1) << (sizeof(table_map)*8-2)) 90 #define RAND_TABLE_BIT (((table_map) 1) << (sizeof(table_map)*8-1)) 91 #define PSEUDO_TABLE_BITS (PARAM_TABLE_BIT | OUTER_REF_TABLE_BIT | \ 92 RAND_TABLE_BIT) 93 #define CONNECT_STRING_MAXLEN 65535 /* stored in 2 bytes in .frm */ 94 #define MAX_FIELDS 4096 /* Limit in the .frm file */ 95 #define MAX_PARTITIONS 8192 96 97 #define MAX_SELECT_NESTING (SELECT_NESTING_MAP_SIZE - 1) 98 99 #define MAX_SORT_MEMORY 2048*1024 100 #define MIN_SORT_MEMORY 1024 101 102 /* Some portable defines */ 103 104 #define STRING_BUFFER_USUAL_SIZE 80 105 106 /* Memory allocated when parsing a statement / saving a statement */ 107 #define MEM_ROOT_BLOCK_SIZE 8192 108 #define MEM_ROOT_PREALLOC 8192 109 #define TRANS_MEM_ROOT_BLOCK_SIZE 4096 110 #define TRANS_MEM_ROOT_PREALLOC 4096 111 112 #define DEFAULT_ERROR_COUNT 64 113 #define EXTRA_RECORDS 10 /* Extra records in sort */ 114 #define SCROLL_EXTRA 5 /* Extra scroll-rows. */ 115 #define FIELD_NAME_USED ((uint) 32768) /* Bit set if fieldname used */ 116 #define FORM_NAME_USED ((uint) 16384) /* Bit set if formname used */ 117 #define FIELD_NR_MASK 16383 /* To get fieldnumber */ 118 #define FERR -1 /* Error from my_functions */ 119 #define CREATE_MODE 0 /* Default mode on new files */ 120 #define NAMES_SEP_CHAR 255 /* Char to sep. names */ 121 122 #define READ_RECORD_BUFFER (uint) (IO_SIZE*8) /* Pointer_buffer_size */ 123 #define DISK_BUFFER_SIZE (uint) (IO_SIZE*16) /* Size of diskbuffer */ 124 125 #define FRM_VER_TRUE_VARCHAR (FRM_VER+4) /* 10 */ 126 #define FRM_VER_EXPRESSSIONS (FRM_VER+5) /* 11 */ 127 #define FRM_VER_CURRENT FRM_VER_EXPRESSSIONS 128 129 /*************************************************************************** 130 Configuration parameters 131 ****************************************************************************/ 132 133 #define ACL_CACHE_SIZE 256 134 #define MAX_PASSWORD_LENGTH 32 135 #define HOST_CACHE_SIZE 128 136 #define MAX_ACCEPT_RETRY 10 // Test accept this many times 137 #define MAX_FIELDS_BEFORE_HASH 32 138 #define USER_VARS_HASH_SIZE 16 139 #define SEQUENCES_HASH_SIZE 16 140 #define TABLE_OPEN_CACHE_MIN 200 141 #define TABLE_OPEN_CACHE_DEFAULT 2000 142 #define TABLE_DEF_CACHE_DEFAULT 400 143 /** 144 We must have room for at least 400 table definitions in the table 145 cache, since otherwise there is no chance prepared 146 statements that use these many tables can work. 147 Prepared statements use table definition cache ids (table_map_id) 148 as table version identifiers. If the table definition 149 cache size is less than the number of tables used in a statement, 150 the contents of the table definition cache is guaranteed to rotate 151 between a prepare and execute. This leads to stable validation 152 errors. In future we shall use more stable version identifiers, 153 for now the only solution is to ensure that the table definition 154 cache can contain at least all tables of a given statement. 155 */ 156 #define TABLE_DEF_CACHE_MIN 400 157 158 /** 159 Maximum number of connections default value. 160 151 is larger than Apache's default max children, 161 to avoid "too many connections" error in a common setup. 162 */ 163 #define MAX_CONNECTIONS_DEFAULT 151 164 165 /* 166 Stack reservation. 167 Feel free to raise this by the smallest amount you can to get the 168 "execution_constants" test to pass. 169 */ 170 #define STACK_MIN_SIZE 16000 // Abort if less stack during eval. 171 172 #define STACK_MIN_SIZE_FOR_OPEN (1024*80) 173 #define STACK_BUFF_ALLOC 352 ///< For stack overrun checks 174 #ifndef MYSQLD_NET_RETRY_COUNT 175 #define MYSQLD_NET_RETRY_COUNT 10 ///< Abort read after this many int. 176 #endif 177 178 #define QUERY_ALLOC_BLOCK_SIZE 16384 179 #define QUERY_ALLOC_PREALLOC_SIZE 24576 180 #define TRANS_ALLOC_BLOCK_SIZE 8192 181 #define TRANS_ALLOC_PREALLOC_SIZE 4096 182 #define RANGE_ALLOC_BLOCK_SIZE 4096 183 #define ACL_ALLOC_BLOCK_SIZE 1024 184 #define UDF_ALLOC_BLOCK_SIZE 1024 185 #define TABLE_ALLOC_BLOCK_SIZE 1024 186 #define WARN_ALLOC_BLOCK_SIZE 2048 187 #define WARN_ALLOC_PREALLOC_SIZE 1024 188 /* 189 Note that if we are using 32K or less, then TCmalloc will use a local 190 heap without locks! 191 */ 192 #define SHOW_ALLOC_BLOCK_SIZE (32768-MALLOC_OVERHEAD) 193 194 /* 195 The following parameters is to decide when to use an extra cache to 196 optimise seeks when reading a big table in sorted order 197 */ 198 #define MIN_FILE_LENGTH_TO_USE_ROW_CACHE (10L*1024*1024) 199 #define MIN_ROWS_TO_USE_TABLE_CACHE 100 200 #define MIN_ROWS_TO_USE_BULK_INSERT 100 201 202 /** 203 The following is used to decide if MySQL should use table scanning 204 instead of reading with keys. The number says how many evaluation of the 205 WHERE clause is comparable to reading one extra row from a table. 206 */ 207 #define TIME_FOR_COMPARE 5 // 5 compares == one read 208 #define TIME_FOR_COMPARE_IDX 20 209 210 #define IDX_BLOCK_COPY_COST ((double) 1 / TIME_FOR_COMPARE) 211 #define IDX_LOOKUP_COST ((double) 1 / 8) 212 213 /** 214 Number of comparisons of table rowids equivalent to reading one row from a 215 table. 216 */ 217 #define TIME_FOR_COMPARE_ROWID (TIME_FOR_COMPARE*100) 218 219 /* cost1 is better that cost2 only if cost1 + COST_EPS < cost2 */ 220 #define COST_EPS 0.001 221 222 /* 223 For sequential disk seeks the cost formula is: 224 DISK_SEEK_BASE_COST + DISK_SEEK_PROP_COST * #blocks_to_skip 225 226 The cost of average seek 227 DISK_SEEK_BASE_COST + DISK_SEEK_PROP_COST*BLOCKS_IN_AVG_SEEK =1.0. 228 */ 229 #define DISK_SEEK_BASE_COST ((double)0.9) 230 231 #define BLOCKS_IN_AVG_SEEK 128 232 233 #define DISK_SEEK_PROP_COST ((double)0.1/BLOCKS_IN_AVG_SEEK) 234 235 236 /** 237 Number of rows in a reference table when refereed through a not unique key. 238 This value is only used when we don't know anything about the key 239 distribution. 240 */ 241 #define MATCHING_ROWS_IN_OTHER_TABLE 10 242 243 /* 244 Subquery materialization-related constants 245 */ 246 #define HEAP_TEMPTABLE_LOOKUP_COST 0.05 247 #define DISK_TEMPTABLE_LOOKUP_COST 1.0 248 #define SORT_INDEX_CMP_COST 0.02 249 250 251 #define COST_MAX (DBL_MAX * (1.0 - DBL_EPSILON)) 252 253 #define COST_ADD(c,d) (COST_MAX - (d) > (c) ? (c) + (d) : COST_MAX) 254 255 #define COST_MULT(c,f) (COST_MAX / (f) > (c) ? (c) * (f) : COST_MAX) 256 257 258 #define MY_CHARSET_BIN_MB_MAXLEN 1 259 260 /** Don't pack string keys shorter than this (if PACK_KEYS=1 isn't used). */ 261 #define KEY_DEFAULT_PACK_LENGTH 8 262 263 /** Characters shown for the command in 'show processlist'. */ 264 #define PROCESS_LIST_WIDTH 100 265 /* Characters shown for the command in 'information_schema.processlist' */ 266 #define PROCESS_LIST_INFO_WIDTH 65535 267 268 #define PRECISION_FOR_DOUBLE 53 269 #define PRECISION_FOR_FLOAT 24 270 271 /* -[digits].E+## */ 272 #define MAX_FLOAT_STR_LENGTH (FLT_DIG + 6) 273 /* -[digits].E+### */ 274 #define MAX_DOUBLE_STR_LENGTH (DBL_DIG + 7) 275 276 /* 277 Default time to wait before aborting a new client connection 278 that does not respond to "initial server greeting" timely 279 */ 280 #define CONNECT_TIMEOUT 10 281 /* Wait 5 minutes before removing thread from thread cache */ 282 #define THREAD_CACHE_TIMEOUT 5*60 283 284 /* The following can also be changed from the command line */ 285 #define DEFAULT_CONCURRENCY 10 286 #define DELAYED_LIMIT 100 /**< pause after xxx inserts */ 287 #define DELAYED_QUEUE_SIZE 1000 288 #define DELAYED_WAIT_TIMEOUT (5*60) /**< Wait for delayed insert */ 289 #define MAX_CONNECT_ERRORS 100 ///< errors before disabling host 290 291 #define LONG_TIMEOUT ((ulong) 3600L*24L*365L) 292 293 /** 294 Maximum length of time zone name that we support (Time zone name is 295 char(64) in db). mysqlbinlog needs it. 296 */ 297 #define MAX_TIME_ZONE_NAME_LENGTH (NAME_LEN + 1) 298 299 #if defined(__WIN__) 300 301 #define INTERRUPT_PRIOR -2 302 #define CONNECT_PRIOR -1 303 #define WAIT_PRIOR 0 304 #define QUERY_PRIOR 2 305 #else 306 #define INTERRUPT_PRIOR 10 307 #define CONNECT_PRIOR 9 308 #define WAIT_PRIOR 8 309 #define QUERY_PRIOR 6 310 #endif /* __WIN92__ */ 311 312 #endif /* SQL_CONST_INCLUDED */ 313