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 #if PG_VERSION_NUM >= 90200
  85                 Oid                     indexOid = RangeVarGetRelid(makeRangeVarFromNameList(stringToQualifiedNameList(curname)),
  86                                                                                                 NoLock, true);
  87 #else
  88                 Oid                     indexOid = RangeVarGetRelid(makeRangeVarFromNameList(stringToQualifiedNameList(curname)),
  89                                                                                                 true);
  90 #endif
  91
  92                 if (indexOid == InvalidOid)
  93                 {
  94 #if PG_VERSION_NUM >= 90100
  95                         if (doit == false)
  96 #endif
  97                                 elog(WARNING,"'%s' does not exist", curname);
  98                         continue;
  99                 }
 100                 else if ( get_rel_relkind(indexOid) != RELKIND_INDEX )
 101                 {
 102 #if PG_VERSION_NUM >= 90100
 103                         if (doit == false)
 104 #endif
 105                                 elog(WARNING,"'%s' is not an index", curname);
 106                         continue;
 107                 }
 108                 else if (doit)
 109                 {
 110                         newOids[i++] = indexOid;
 111                 }
 112         }
 113
 114         if (doit)
 115         {
 116                 if (isDisable)
 117                 {
 118                         nDisabledIndexes = nOids;
 119                         disabledIndexes = newOids;
 120                 }
 121                 else
 122                 {
 123                         nEnabledIndexes = nOids;
 124                         enabledIndexes = newOids;
 125                 }
 126         }
 127
 128         pfree(rawname);
 129         list_free(namelist);
 130
 131         return newval;
 132
 133 cleanup:
 134         if (newOids)
 135                 free(newOids);
 136         pfree(rawname);
 137         list_free(namelist);
 138         return NULL;
 139 }
 140
 141 static const char *
 142 assignDisabledIndexes(const char * newval, bool doit, GucSource source)
 143 {
 144         return indexesAssign(newval, doit, source, true);
 145 }
 146
 147 static const char *
 148 assignEnabledIndexes(const char * newval, bool doit, GucSource source)
 149 {
 150         return indexesAssign(newval, doit, source, false);
 151 }
 152
 153 #if PG_VERSION_NUM >= 90100
 154
 155 static bool
 156 checkDisabledIndexes(char **newval, void **extra, GucSource source)
 157 {
 158         char *val;
 159
 160         val = (char*)indexesAssign(*newval, false, source, true);
 161
 162         if (val)
 163         {
 164                 *newval = val;
 165                 return true;
 166         }
 167
 168         return false;
 169 }
 170
 171 static bool
 172 checkEnabledIndexes(char **newval, void **extra, GucSource source)
 173 {
 174         char *val;
 175
 176         val = (char*)indexesAssign(*newval, false, source, false);
 177
 178         if (val)
 179         {
 180                 *newval = val;
 181                 return true;
 182         }
 183
 184         return false;
 185 }
 186
 187 static void
 188 assignDisabledIndexesNew(const char *newval, void *extra)
 189 {
 190         assignDisabledIndexes(newval, true, PGC_S_USER /* doesn't matter */);
 191 }
 192
 193 static void
 194 assignEnabledIndexesNew(const char *newval, void *extra)
 195 {
 196         assignEnabledIndexes(newval, true, PGC_S_USER /* doesn't matter */);
 197 }
 198
 199 #endif
 200
 201 static void
 202 indexFilter(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) {
 203         int i;
 204
 205         for(i=0;i<nDisabledIndexes;i++)
 206         {
 207                 ListCell   *l;
 208
 209                 foreach(l, rel->indexlist)
 210                 {
 211                         IndexOptInfo    *info = (IndexOptInfo*)lfirst(l);
 212
 213                         if (disabledIndexes[i] == info->indexoid)
 214                         {
 215                                 int j;
 216
 217                                 for(j=0; j<nEnabledIndexes; j++)
 218                                         if (enabledIndexes[j] == info->indexoid)
 219                                                 break;
 220
 221                                 if (j >= nEnabledIndexes)
 222                                         rel->indexlist = list_delete_ptr(rel->indexlist, info);
 223
 224                                 break;
 225                         }
 226                 }
 227         }
 228
 229         if (fix_empty_table && rel)
 230         {
 231
 232
 233         }
 234
 235 }
 236
 237 static void
 238 execPlantuner(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) {
 239         Relation        relation;
 240
 241         relation = heap_open(relationObjectId, NoLock);
 242         if (relation->rd_rel->relkind == RELKIND_RELATION)
 243         {
 244                 if (fix_empty_table && RelationGetNumberOfBlocks(relation) == 0)
 245                 {
 246                         /*
 247                          * estimate_rel_size() could be too pessimistic for particular
 248                          * workload
 249                          */
 250                         rel->pages = 0.0;
 251                         rel->tuples = 0.0;
 252                 }
 253
 254                 indexFilter(root, relationObjectId, inhparent, rel);
 255         }
 256         heap_close(relation, NoLock);
 257
 258         /*
 259          * Call next hook if it exists
 260          */
 261         if (prevHook)
 262                 prevHook(root, relationObjectId, inhparent, rel);
 263 }
 264
 265 static const char*
 266 IndexFilterShow(Oid* indexes, int nIndexes)
 267 {
 268         char    *val, *ptr;
 269         int     i,
 270                         len;
 271
 272         len = 1 /* \0 */ + nIndexes * (2 * NAMEDATALEN + 2 /* ', ' */ + 1 /* . */);
 273         ptr = val = palloc(len);
 274
 275         *ptr ='\0';
 276         for(i=0; i<nIndexes; i++)
 277         {
 278                 char    *relname = get_rel_name(indexes[i]);
 279                 Oid     nspOid = get_rel_namespace(indexes[i]);
 280                 char    *nspname = get_namespace_name(nspOid);
 281
 282                 if ( relname == NULL || nspOid == InvalidOid || nspname == NULL )
 283                         continue;
 284
 285                 ptr += snprintf(ptr, len - (ptr - val), "%s%s.%s",
 286                                                                                                 (i==0) ? "" : ", ",
 287                                                                                                 nspname,
 288                                                                                                 relname);
 289         }
 290
 291         return val;
 292 }
 293
 294 static const char*
 295 disabledIndexFilterShow(void)
 296 {
 297         return IndexFilterShow(disabledIndexes, nDisabledIndexes);
 298 }
 299
 300 static const char*
 301 enabledIndexFilterShow(void)
 302 {
 303         return IndexFilterShow(enabledIndexes, nEnabledIndexes);
 304 }
 305
 306 void _PG_init(void);
 307 void
 308 _PG_init(void)
 309 {
 310     DefineCustomStringVariable(
 311                 "plantuner.forbid_index",
 312                 "List of forbidden indexes (deprecated)",
 313                 "Listed indexes will not be used in queries (deprecated, use plantuner.disable_index)",
 314                 &disableIndexesOutStr,
 315                 "",
 316                 PGC_USERSET,
 317                 0,
 318 #if PG_VERSION_NUM >= 90100
 319                 checkDisabledIndexes,
 320                 assignDisabledIndexesNew,
 321 #else
 322                 assignDisabledIndexes,
 323 #endif
 324                 disabledIndexFilterShow
 325         );
 326
 327     DefineCustomStringVariable(
 328                 "plantuner.disable_index",
 329                 "List of disabled indexes",
 330                 "Listed indexes will not be used in queries",
 331                 &disableIndexesOutStr,
 332                 "",
 333                 PGC_USERSET,
 334                 0,
 335 #if PG_VERSION_NUM >= 90100
 336                 checkDisabledIndexes,
 337                 assignDisabledIndexesNew,
 338 #else
 339                 assignDisabledIndexes,
 340 #endif
 341                 disabledIndexFilterShow
 342         );
 343
 344     DefineCustomStringVariable(
 345                 "plantuner.enable_index",
 346                 "List of enabled indexes (overload plantuner.disable_index)",
 347                 "Listed indexes which could be used in queries even they are listed in plantuner.disable_index",
 348                 &enableIndexesOutStr,
 349                 "",
 350                 PGC_USERSET,
 351                 0,
 352 #if PG_VERSION_NUM >= 90100
 353                 checkEnabledIndexes,
 354                 assignEnabledIndexesNew,
 355 #else
 356                 assignEnabledIndexes,
 357 #endif
 358                 enabledIndexFilterShow
 359         );
 360
 361     DefineCustomBoolVariable(
 362                 "plantuner.fix_empty_table",
 363                 "Sets to zero estimations for empty tables",
 364                 "Sets to zero estimations for empty or newly created tables",
 365                 &fix_empty_table,
 366 #if PG_VERSION_NUM >= 80400
 367                 fix_empty_table,
 368 #endif
 369                 PGC_USERSET,
 370 #if PG_VERSION_NUM >= 80400
 371                 GUC_NOT_IN_SAMPLE,
 372 #if PG_VERSION_NUM >= 90100
 373                 NULL,
 374 #endif
 375 #endif
 376                 NULL,
 377                 NULL
 378         );
 379
 380         if (get_relation_info_hook != execPlantuner )
 381         {
 382                 prevHook = get_relation_info_hook;
 383                 get_relation_info_hook = execPlantuner;
 384         }
 385 }