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