--- /dev/null
+/*
+ * Copyright (c) 2009 Teodor Sigaev <teodor@sigaev.ru>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the author nor the names of any co-contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY CONTRIBUTORS ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
--- /dev/null
+subdir = contrib/plantuner
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+
+MODULE_big = plantuner
+DOCS = README.plantuner
+REGRESS = plantuner
+OBJS=plantuner.o
+
+include $(top_srcdir)/contrib/contrib-global.mk
--- /dev/null
+plantuner module provides plantuner.forbid_index GUC which contains comma-separated
+list of indexes forbidden to use in query.
+
+USAGE (see sql/plantuner.sql:
+% LOAD 'plantuner';
+% SET plantuner.forbid_index="i_idx, j_idx";
+% SET enable_seqscan=off;
+% explain SELECT * FROM wow;
+ QUERY PLAN
+--------------------------------------------------------------------------
+ Seq Scan on wow (cost=10000000000.00..10000000031.40 rows=2140 width=8)
+
+
+It's recommended to load library by shared_preload_libraries option
+in postgresql.conf
--- /dev/null
+LOAD 'plantuner';
+SHOW plantuner.forbid_index;
+ plantuner.forbid_index
+------------------------
+
+(1 row)
+
+CREATE TABLE wow (i int, j int);
+CREATE INDEX i_idx ON wow (i);
+CREATE INDEX j_idx ON wow (j);
+SET enable_seqscan=off;
+SELECT * FROM wow;
+ i | j
+---+---
+(0 rows)
+
+SET plantuner.forbid_index="i_idx, j_idx";
+SELECT * FROM wow;
+ i | j
+---+---
+(0 rows)
+
+SHOW plantuner.forbid_index;
+ plantuner.forbid_index
+----------------------------
+ public.i_idx, public.j_idx
+(1 row)
+
+SET plantuner.forbid_index="i_idx, nonexistent, public.j_idx, wow";
+WARNING: 'nonexistent' does not exist
+WARNING: 'wow' is not an index
+SHOW plantuner.forbid_index;
+ plantuner.forbid_index
+----------------------------
+ public.i_idx, public.j_idx
+(1 row)
+
--- /dev/null
+/*
+ * Copyright (c) 2009 Teodor Sigaev <teodor@sigaev.ru>
+ */
+
+#include <postgres.h>
+
+#include <fmgr.h>
+#include <catalog/namespace.h>
+#include <catalog/pg_class.h>
+#include <nodes/pg_list.h>
+#include <optimizer/plancat.h>
+#include <utils/builtins.h>
+#include <utils/guc.h>
+#include <utils/lsyscache.h>
+
+PG_MODULE_MAGIC;
+
+static int nIndexesOut = 0;
+static Oid *indexesOut = NULL;
+get_relation_info_hook_type prevHook = NULL;
+
+static char *indexesOutStr = "";
+
+static const char *
+indexesOutAssign(const char * newval, bool doit, GucSource source)
+{
+ char *rawname;
+ List *namelist;
+ ListCell *l;
+ Oid *newOids = NULL;
+ int nOids = 0,
+ i = 0;
+
+ rawname = pstrdup(newval);
+
+ if (!SplitIdentifierString(rawname, ',', &namelist))
+ goto cleanup;
+
+ if (doit)
+ {
+ nOids = list_length(namelist);
+ newOids = malloc(sizeof(Oid) * (nOids+1));
+ if (!newOids)
+ elog(ERROR,"could not allocate %d bytes", sizeof(Oid) * (nOids+1));
+ }
+
+ foreach(l, namelist)
+ {
+ char *curname = (char *) lfirst(l);
+ Oid indexOid = RangeVarGetRelid(makeRangeVarFromNameList(stringToQualifiedNameList(curname)), true);
+
+ if (indexOid == InvalidOid)
+ {
+ elog(WARNING,"'%s' does not exist", curname);
+ continue;
+ }
+ else if ( get_rel_relkind(indexOid) != RELKIND_INDEX )
+ {
+ elog(WARNING,"'%s' is not an index", curname);
+ continue;
+ }
+ else if (doit)
+ {
+ newOids[i++] = indexOid;
+ }
+ }
+
+ if (doit)
+ {
+ nIndexesOut = nOids;
+ indexesOut = newOids;
+ }
+
+ pfree(rawname);
+ list_free(namelist);
+
+ return newval;
+
+cleanup:
+ if (newOids)
+ free(newOids);
+ pfree(rawname);
+ list_free(namelist);
+ return NULL;
+}
+
+
+static void
+indexFilter(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) {
+ int i;
+
+ for(i=0;i<nIndexesOut;i++)
+ {
+ ListCell *l;
+
+ foreach(l, rel->indexlist)
+ {
+ IndexOptInfo *info = (IndexOptInfo*)lfirst(l);
+
+ if (indexesOut[i] == info->indexoid)
+ {
+ rel->indexlist = list_delete_ptr(rel->indexlist, info);
+ break;
+ }
+ }
+ }
+
+ /*
+ * Call next hook if it exists
+ */
+ if (prevHook)
+ prevHook(root, relationObjectId, inhparent, rel);
+}
+
+static const char*
+IndexFilterShow(void)
+{
+ char *val, *ptr;
+ int i,
+ len;
+
+ len = 1 /* \0 */ + nIndexesOut * (2 * NAMEDATALEN + 2 /* ', ' */ + 1 /* . */);
+ ptr = val = palloc(len);
+
+ *ptr ='\0';
+ for(i=0; i<nIndexesOut; i++)
+ {
+ char *relname = get_rel_name(indexesOut[i]);
+ Oid nspOid = get_rel_namespace(indexesOut[i]);
+ char *nspname = get_namespace_name(nspOid);
+
+ if ( relname == NULL || nspOid == InvalidOid || nspname == NULL )
+ continue;
+
+ ptr += snprintf(ptr, len - (ptr - val), "%s%s.%s",
+ (i==0) ? "" : ", ",
+ nspname,
+ relname);
+ }
+
+ return val;
+}
+
+void _PG_init(void);
+void
+_PG_init(void)
+{
+ DefineCustomStringVariable(
+ "plantuner.forbid_index",
+ "List of forbidden indexes",
+ "Listed indexes will not be used in queries",
+ &indexesOutStr,
+ "",
+ PGC_USERSET,
+ 0,
+ indexesOutAssign,
+ IndexFilterShow
+ );
+
+ if (get_relation_info_hook != indexFilter )
+ {
+ prevHook = get_relation_info_hook;
+ get_relation_info_hook = indexFilter;
+ }
+}
--- /dev/null
+LOAD 'plantuner';
+
+SHOW plantuner.forbid_index;
+
+CREATE TABLE wow (i int, j int);
+CREATE INDEX i_idx ON wow (i);
+CREATE INDEX j_idx ON wow (j);
+
+SET enable_seqscan=off;
+
+SELECT * FROM wow;
+
+SET plantuner.forbid_index="i_idx, j_idx";
+
+SELECT * FROM wow;
+
+SHOW plantuner.forbid_index;
+
+SET plantuner.forbid_index="i_idx, nonexistent, public.j_idx, wow";
+
+SHOW plantuner.forbid_index;
projects / plantuner.git / commitdiff