plantuner.c

   1 /*
   2  * Copyright (c) 2009 Teodor Sigaev <teodor@sigaev.ru>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *        notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *        notice, this list of conditions and the following disclaimer in the
  12  *        documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the author nor the names of any co-contributors
  14  *        may be used to endorse or promote products derived from this software
  15  *        without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY CONTRIBUTORS ``AS IS'' AND ANY EXPRESS
  18  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED. IN NO EVENT SHALL CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  23  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
  25  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  27  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include <postgres.h>
  31
  32 #include <fmgr.h>
  33 #include <access/heapam.h>
  34 #include <catalog/namespace.h>
  35 #include <catalog/pg_class.h>
  36 #include <nodes/pg_list.h>
  37 #include <optimizer/plancat.h>
  38 #include <storage/bufmgr.h>
  39 #include <utils/builtins.h>
  40 #include <utils/guc.h>
  41 #include <utils/lsyscache.h>
  42 #include <utils/rel.h>
  43
  44 PG_MODULE_MAGIC;
  45
  46 static int      nDisabledIndexes = 0;
  47 static Oid      *disabledIndexes = NULL;
  48 static char *disableIndexesOutStr = "";
  49
  50 static int      nEnabledIndexes = 0;
  51 static Oid      *enabledIndexes = NULL;
  52 static char *enableIndexesOutStr = "";
  53
  54 get_relation_info_hook_type     prevHook = NULL;
  55 static bool     fix_empty_table = false;
  56
  57
  58 static const char *
  59 indexesAssign(const char * newval, bool doit, GucSource source, bool isDisable)
  60 {
  61         char       *rawname;
  62         List       *namelist;
  63         ListCell   *l;
  64         Oid                     *newOids = NULL;
  65         int                     nOids = 0,
  66                                 i = 0;
  67
  68         rawname = pstrdup(newval);
  69
  70         if (!SplitIdentifierString(rawname, ',', &namelist))
  71                 goto cleanup;
  72
  73         if (doit)
  74         {
  75                 nOids = list_length(namelist);
  76                 newOids = malloc(sizeof(Oid) * (nOids+1));
  77                 if (!newOids)
  78                         elog(ERROR,"could not allocate %d bytes", (int)(sizeof(Oid) * (nOids+1)));
  79         }
  80
  81         foreach(l, namelist)
  82         {
  83                 char            *curname = (char *) lfirst(l);
  84                 Oid                     indexOid = RangeVarGetRelid(makeRangeVarFromNameList(stringToQualifiedNameList(curname)),
  85 #if PG_VERSION_NUM >= 90200
  86                                                                                                 NoLock,
  87 #endif
  88                                                                                                 true);
  89
  90                 if (indexOid == InvalidOid)
  91                 {
  92 #if PG_VERSION_NUM >= 90100
  93                         if (doit == false)
  94 #endif
  95                                 elog(WARNING,"'%s' does not exist", curname);
  96                         continue;
  97                 }
  98                 else if ( get_rel_relkind(indexOid) != RELKIND_INDEX )
  99                 {
 100 #if PG_VERSION_NUM >= 90100
 101                         if (doit == false)
 102 #endif
 103                                 elog(WARNING,"'%s' is not an index", curname);
 104                         continue;
 105                 }
 106                 else if (doit)
 107                 {
 108                         newOids[i++] = indexOid;
 109                 }
 110         }
 111
 112         if (doit)
 113         {
 114                 if (isDisable)
 115                 {
 116                         nDisabledIndexes = nOids;
 117                         disabledIndexes = newOids;
 118                 }
 119                 else
 120                 {
 121                         nEnabledIndexes = nOids;
 122                         enabledIndexes = newOids;
 123                 }
 124         }
 125
 126         pfree(rawname);
 127         list_free(namelist);
 128
 129         return newval;
 130
 131 cleanup:
 132         if (newOids)
 133                 free(newOids);
 134         pfree(rawname);
 135         list_free(namelist);
 136         return NULL;
 137 }
 138
 139 static const char *
 140 assignDisabledIndexes(const char * newval, bool doit, GucSource source)
 141 {
 142         return indexesAssign(newval, doit, source, true);
 143 }
 144
 145 static const char *
 146 assignEnabledIndexes(const char * newval, bool doit, GucSource source)
 147 {
 148         return indexesAssign(newval, doit, source, false);
 149 }
 150
 151 #if PG_VERSION_NUM >= 90100
 152
 153 static bool
 154 checkDisabledIndexes(char **newval, void **extra, GucSource source)
 155 {
 156         char *val;
 157
 158         val = (char*)indexesAssign(*newval, false, source, true);
 159
 160         if (val)
 161         {
 162                 *newval = val;
 163                 return true;
 164         }
 165
 166         return false;
 167 }
 168
 169 static bool
 170 checkEnabledIndexes(char **newval, void **extra, GucSource source)
 171 {
 172         char *val;
 173
 174         val = (char*)indexesAssign(*newval, false, source, false);
 175
 176         if (val)
 177         {
 178                 *newval = val;
 179                 return true;
 180         }
 181
 182         return false;
 183 }
 184
 185 static void
 186 assignDisabledIndexesNew(const char *newval, void *extra)
 187 {
 188         assignDisabledIndexes(newval, true, PGC_S_USER /* doesn't matter */);
 189 }
 190
 191 static void
 192 assignEnabledIndexesNew(const char *newval, void *extra)
 193 {
 194         assignEnabledIndexes(newval, true, PGC_S_USER /* doesn't matter */);
 195 }
 196
 197 #endif
 198
 199 static void
 200 indexFilter(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) {
 201         int i;
 202
 203         for(i=0;i<nDisabledIndexes;i++)
 204         {
 205                 ListCell   *l;
 206
 207                 foreach(l, rel->indexlist)
 208                 {
 209                         IndexOptInfo    *info = (IndexOptInfo*)lfirst(l);
 210
 211                         if (disabledIndexes[i] == info->indexoid)
 212                         {
 213                                 int j;
 214
 215                                 for(j=0; j<nEnabledIndexes; j++)
 216                                         if (enabledIndexes[j] == info->indexoid)
 217                                                 break;
 218
 219                                 if (j >= nEnabledIndexes)
 220                                         rel->indexlist = list_delete_ptr(rel->indexlist, info);
 221
 222                                 break;
 223                         }
 224                 }
 225         }
 226
 227         if (fix_empty_table && rel)
 228         {
 229
 230
 231         }
 232
 233 }
 234
 235 static void
 236 execPlantuner(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) {
 237         Relation        relation;
 238
 239         relation = heap_open(relationObjectId, NoLock);
 240         if (relation->rd_rel->relkind == RELKIND_RELATION)
 241         {
 242                 if (fix_empty_table && RelationGetNumberOfBlocks(relation) == 0)
 243                 {
 244                         /*
 245                          * estimate_rel_size() could be too pessimistic for particular
 246                          * workload
 247                          */
 248                         rel->pages = 0.0;
 249                         rel->tuples = 0.0;
 250                 }
 251
 252                 indexFilter(root, relationObjectId, inhparent, rel);
 253         }
 254         heap_close(relation, NoLock);
 255
 256         /*
 257          * Call next hook if it exists
 258          */
 259         if (prevHook)
 260                 prevHook(root, relationObjectId, inhparent, rel);
 261 }
 262
 263 static const char*
 264 IndexFilterShow(Oid* indexes, int nIndexes)
 265 {
 266         char    *val, *ptr;
 267         int     i,
 268                         len;
 269
 270         len = 1 /* \0 */ + nIndexes * (2 * NAMEDATALEN + 2 /* ', ' */ + 1 /* . */);
 271         ptr = val = palloc(len);
 272
 273         *ptr ='\0';
 274         for(i=0; i<nIndexes; i++)
 275         {
 276                 char    *relname = get_rel_name(indexes[i]);
 277                 Oid     nspOid = get_rel_namespace(indexes[i]);
 278                 char    *nspname = get_namespace_name(nspOid);
 279
 280                 if ( relname == NULL || nspOid == InvalidOid || nspname == NULL )
 281                         continue;
 282
 283                 ptr += snprintf(ptr, len - (ptr - val), "%s%s.%s",
 284                                                                                                 (i==0) ? "" : ", ",
 285                                                                                                 nspname,
 286                                                                                                 relname);
 287         }
 288
 289         return val;
 290 }
 291
 292 static const char*
 293 disabledIndexFilterShow()
 294 {
 295         return IndexFilterShow(disabledIndexes, nDisabledIndexes);
 296 }
 297
 298 static const char*
 299 enabledIndexFilterShow()
 300 {
 301         return IndexFilterShow(enabledIndexes, nEnabledIndexes);
 302 }
 303
 304 void _PG_init(void);
 305 void
 306 _PG_init(void)
 307 {
 308     DefineCustomStringVariable(
 309                 "plantuner.forbid_index",
 310                 "List of forbidden indexes (deprecated)",
 311                 "Listed indexes will not be used in queries (deprecated, use plantuner.disable_index)",
 312                 &disableIndexesOutStr,
 313                 "",
 314                 PGC_USERSET,
 315                 0,
 316 #if PG_VERSION_NUM >= 90100
 317                 checkDisabledIndexes,
 318                 assignDisabledIndexesNew,
 319 #else
 320                 assignDisabledIndexes,
 321 #endif
 322                 disabledIndexFilterShow
 323         );
 324
 325     DefineCustomStringVariable(
 326                 "plantuner.disable_index",
 327                 "List of disabled indexes",
 328                 "Listed indexes will not be used in queries",
 329                 &disableIndexesOutStr,
 330                 "",
 331                 PGC_USERSET,
 332                 0,
 333 #if PG_VERSION_NUM >= 90100
 334                 checkDisabledIndexes,
 335                 assignDisabledIndexesNew,
 336 #else
 337                 assignDisabledIndexes,
 338 #endif
 339                 disabledIndexFilterShow
 340         );
 341
 342     DefineCustomStringVariable(
 343                 "plantuner.enable_index",
 344                 "List of enabled indexes (overload plantuner.disable_index)",
 345                 "Listed indexes which could be used in queries even they are listed in plantuner.disable_index",
 346                 &enableIndexesOutStr,
 347                 "",
 348                 PGC_USERSET,
 349                 0,
 350 #if PG_VERSION_NUM >= 90100
 351                 checkEnabledIndexes,
 352                 assignEnabledIndexesNew,
 353 #else
 354                 assignEnabledIndexes,
 355 #endif
 356                 enabledIndexFilterShow
 357         );
 358
 359     DefineCustomBoolVariable(
 360                 "plantuner.fix_empty_table",
 361                 "Sets to zero estimations for empty tables",
 362                 "Sets to zero estimations for empty or newly created tables",
 363                 &fix_empty_table,
 364 #if PG_VERSION_NUM >= 80400
 365                 fix_empty_table,
 366 #endif
 367                 PGC_USERSET,
 368 #if PG_VERSION_NUM >= 80400
 369                 GUC_NOT_IN_SAMPLE,
 370 #if PG_VERSION_NUM >= 90100
 371                 NULL,
 372 #endif
 373 #endif
 374                 NULL,
 375                 NULL
 376         );
 377
 378         if (get_relation_info_hook != execPlantuner )
 379         {
 380                 prevHook = get_relation_info_hook;
 381                 get_relation_info_hook = execPlantuner;
 382         }
 383 }