]> granicus.if.org Git - postgresql/commitdiff
Support "x IS NOT NULL" clauses as indexscan conditions. This turns out
authorTom Lane <tgl@sss.pgh.pa.us>
Fri, 1 Jan 2010 21:53:49 +0000 (21:53 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Fri, 1 Jan 2010 21:53:49 +0000 (21:53 +0000)
to be just a minor extension of the previous patch that made "x IS NULL"
indexable, because we can treat the IS NOT NULL condition as if it were
"x < NULL" or "x > NULL" (depending on the index's NULLS FIRST/LAST option),
just like IS NULL is treated like "x = NULL".  Aside from any possible
usefulness in its own right, this is an important improvement for
index-optimized MAX/MIN aggregates: it is now reliably possible to get
a column's min or max value cheaply, even when there are a lot of nulls
cluttering the interesting end of the index.

18 files changed:
doc/src/sgml/catalogs.sgml
doc/src/sgml/indexam.sgml
doc/src/sgml/indices.sgml
src/backend/access/common/scankey.c
src/backend/access/gist/gistget.c
src/backend/access/gist/gistscan.c
src/backend/access/nbtree/nbtutils.c
src/backend/executor/nodeIndexscan.c
src/backend/optimizer/path/indxpath.c
src/backend/optimizer/plan/createplan.c
src/backend/optimizer/plan/planagg.c
src/backend/utils/adt/selfuncs.c
src/include/access/skey.h
src/include/catalog/pg_am.h
src/include/nodes/relation.h
src/include/optimizer/planmain.h
src/test/regress/expected/create_index.out
src/test/regress/sql/create_index.sql

index 0acd79361bd3688d5d24d6586b34970ce0d64ea6..9f81dc209ffe087c9a6a81a02bc4c963022b5935 100644 (file)
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.215 2009/12/29 20:11:42 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/catalogs.sgml,v 2.216 2010/01/01 21:53:48 tgl Exp $ -->
 <!--
  Documentation of the system catalogs, directed toward PostgreSQL developers
  -->
       <entry><structfield>amsearchnulls</structfield></entry>
       <entry><type>bool</type></entry>
       <entry></entry>
-      <entry>Does the access method support IS NULL searches?</entry>
+      <entry>Does the access method support IS NULL/NOT NULL searches?</entry>
      </row>
 
      <row>
index b81cd27d313c1494efdd88d14b93e4572aedaf00..97af54644565c2b091fe8cf4f4fa35fb1bb69e1c 100644 (file)
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/indexam.sgml,v 2.31 2009/07/29 20:56:17 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/indexam.sgml,v 2.32 2010/01/01 21:53:49 tgl Exp $ -->
 
 <chapter id="indexam">
  <title>Index Access Method Interface Definition</title>
    null values.  An index access method that sets
    <structfield>amindexnulls</structfield> may also set
    <structfield>amsearchnulls</structfield>, indicating that it supports
-   <literal>IS NULL</> clauses as search conditions.
+   <literal>IS NULL</> and <literal>IS NOT NULL</> clauses as search
+   conditions.
   </para>
 
  </sect1>
index 7801b099f2235b5ff90c23dc908d62ff8e98bb7b..0ab3e25e80b8718966288a7f9e779a330cfeabac 100644 (file)
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.79 2009/08/07 20:54:31 alvherre Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/indices.sgml,v 1.80 2010/01/01 21:53:49 tgl Exp $ -->
 
 <chapter id="indexes">
  <title id="indexes-title">Indexes</title>
@@ -147,8 +147,8 @@ CREATE INDEX test1_id_index ON test1 (id);
 
    Constructs equivalent to combinations of these operators, such as
    <literal>BETWEEN</> and <literal>IN</>, can also be implemented with
-   a B-tree index search.  Also, an <literal>IS NULL</> condition on
-   an index column can be used with a B-tree index.
+   a B-tree index search.  Also, an <literal>IS NULL</> or <literal>IS NOT
+   NULL</> condition on an index column can be used with a B-tree index.
   </para>
 
   <para>
@@ -180,8 +180,7 @@ CREATE INDEX test1_id_index ON test1 (id);
    Hash indexes can only handle simple equality comparisons.
    The query planner will consider using a hash index whenever an
    indexed column is involved in a comparison using the
-   <literal>=</literal> operator.  (Hash indexes do not support
-   <literal>IS NULL</> searches.)
+   <literal>=</literal> operator.
    The following command is used to create a hash index:
 <synopsis>
 CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> USING hash (<replaceable>column</replaceable>);
@@ -1025,7 +1024,7 @@ SELECT am.amname AS index_method,
      real statistics, some default values are assumed, which are
      almost certain to be inaccurate.  Examining an application's
      index usage without having run <command>ANALYZE</command> is
-     therefore a lost cause. 
+     therefore a lost cause.
      See <xref linkend="vacuum-for-statistics" endterm="vacuum-for-statistics-title">
      and <xref linkend="autovacuum" endterm="autovacuum-title"> for more information.
     </para>
index 2524369abe43fd16f9c3aea8460a58bb50741b2a..f066becf0127cb4ad408701f17098a531c09d6eb 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/common/scankey.c,v 1.32 2009/01/01 17:23:34 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/common/scankey.c,v 1.33 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,7 +21,7 @@
  * ScanKeyEntryInitialize
  *             Initializes a scan key entry given all the field values.
  *             The target procedure is specified by OID (but can be invalid
- *             if SK_SEARCHNULL is set).
+ *             if SK_SEARCHNULL or SK_SEARCHNOTNULL is set).
  *
  * Note: CurrentMemoryContext at call should be as long-lived as the ScanKey
  * itself, because that's what will be used for any subsidiary info attached
@@ -45,7 +45,7 @@ ScanKeyEntryInitialize(ScanKey entry,
                fmgr_info(procedure, &entry->sk_func);
        else
        {
-               Assert(flags & SK_SEARCHNULL);
+               Assert(flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
                MemSet(&entry->sk_func, 0, sizeof(entry->sk_func));
        }
 }
index a094495b8a9552d060187a279a3b2f594c7c13be..98104a7a9f4851cfa0abb7c32101f23214882230 100644 (file)
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/gist/gistget.c,v 1.82 2009/10/08 22:34:57 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/gist/gistget.c,v 1.83 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -413,14 +413,20 @@ gistindex_keytest(IndexTuple tuple,
                {
                        /*
                         * On non-leaf page we can't conclude that child hasn't NULL
-                        * values because of assumption in GiST: uinon (VAL, NULL) is VAL
-                        * But if on non-leaf page key IS  NULL then all childs has NULL.
+                        * values because of assumption in GiST: union (VAL, NULL) is VAL.
+                        * But if on non-leaf page key IS NULL, then all children are NULL.
                         */
-
-                       Assert(key->sk_flags & SK_SEARCHNULL);
-
-                       if (GistPageIsLeaf(p) && !isNull)
-                               return false;
+                       if (key->sk_flags & SK_SEARCHNULL)
+                       {
+                               if (GistPageIsLeaf(p) && !isNull)
+                                       return false;
+                       }
+                       else
+                       {
+                               Assert(key->sk_flags & SK_SEARCHNOTNULL);
+                               if (isNull)
+                                       return false;
+                       }
                }
                else if (isNull)
                {
index aed3e95b4e3401dc314094b4b3b5aba8877cb148..dd43036524ae6972bcf3e7b3199656cc95c5bc39 100644 (file)
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.76 2009/06/11 14:48:53 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/gist/gistscan.c,v 1.77 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -92,15 +92,18 @@ gistrescan(PG_FUNCTION_ARGS)
                 * field.
                 *
                 * Next, if any of keys is a NULL and that key is not marked with
-                * SK_SEARCHNULL then nothing can be found.
+                * SK_SEARCHNULL/SK_SEARCHNOTNULL then nothing can be found (ie,
+                * we assume all indexable operators are strict).
                 */
                for (i = 0; i < scan->numberOfKeys; i++)
                {
-                       scan->keyData[i].sk_func = so->giststate->consistentFn[scan->keyData[i].sk_attno - 1];
+                       ScanKey         skey = &(scan->keyData[i]);
 
-                       if (scan->keyData[i].sk_flags & SK_ISNULL)
+                       skey->sk_func = so->giststate->consistentFn[skey->sk_attno - 1];
+
+                       if (skey->sk_flags & SK_ISNULL)
                        {
-                               if ((scan->keyData[i].sk_flags & SK_SEARCHNULL) == 0)
+                               if (!(skey->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL)))
                                        so->qual_ok = false;
                        }
                }
index b715f60d24fbc91318c8f02144732bd5dbc3e955..33d3c9e8e774733feab6d70941b8d0dea8394c63 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.94 2009/10/08 22:34:57 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.95 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -276,6 +276,11 @@ _bt_preprocess_keys(IndexScanDesc scan)
                 * in any particular strategy in this case, so set it to
                 * BTEqualStrategyNumber --- we can treat IS NULL as an equality
                 * operator for purposes of search strategy.
+                *
+                * Likewise, "x IS NOT NULL" is supported.  We treat that as either
+                * "less than NULL" in a NULLS LAST index, or "greater than NULL"
+                * in a NULLS FIRST index.  However, we have to flip those around in
+                * a DESC index, to allow for the re-flipping that occurs elsewhere.
                 */
                if (cur->sk_flags & SK_ISNULL)
                {
@@ -284,6 +289,21 @@ _bt_preprocess_keys(IndexScanDesc scan)
                                cur->sk_strategy = BTEqualStrategyNumber;
                                cur->sk_subtype = InvalidOid;
                        }
+                       else if (cur->sk_flags & SK_SEARCHNOTNULL)
+                       {
+                               switch (indoption[cur->sk_attno - 1] &
+                                               (INDOPTION_DESC | INDOPTION_NULLS_FIRST))
+                               {
+                                       case 0:         /* ASC / NULLS LAST */
+                                       case INDOPTION_DESC | INDOPTION_NULLS_FIRST:
+                                               cur->sk_strategy = BTLessStrategyNumber;
+                                               break;
+                                       default:
+                                               cur->sk_strategy = BTGreaterStrategyNumber;
+                                               break;
+                               }
+                               cur->sk_subtype = InvalidOid;
+                       }
                        else
                                so->qual_ok = false;
                }
@@ -320,7 +340,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
        {
                if (i < numberOfKeys)
                {
-                       /* See comments above about NULLs and IS NULL handling. */
+                       /* See comments above about NULLs and IS NULL/NOT NULL handling */
                        /* Note: we assume SK_ISNULL is never set in a row header key */
                        if (cur->sk_flags & SK_ISNULL)
                        {
@@ -329,6 +349,21 @@ _bt_preprocess_keys(IndexScanDesc scan)
                                        cur->sk_strategy = BTEqualStrategyNumber;
                                        cur->sk_subtype = InvalidOid;
                                }
+                               else if (cur->sk_flags & SK_SEARCHNOTNULL)
+                               {
+                                       switch (indoption[cur->sk_attno - 1] &
+                                                       (INDOPTION_DESC | INDOPTION_NULLS_FIRST))
+                                       {
+                                               case 0:         /* ASC / NULLS LAST */
+                                               case INDOPTION_DESC | INDOPTION_NULLS_FIRST:
+                                                       cur->sk_strategy = BTLessStrategyNumber;
+                                                       break;
+                                               default:
+                                                       cur->sk_strategy = BTGreaterStrategyNumber;
+                                                       break;
+                                       }
+                                       cur->sk_subtype = InvalidOid;
+                               }
                                else
                                {
                                        so->qual_ok = false;
@@ -365,13 +400,6 @@ _bt_preprocess_keys(IndexScanDesc scan)
                                        if (!chk || j == (BTEqualStrategyNumber - 1))
                                                continue;
 
-                                       /* IS NULL together with any other predicate must fail */
-                                       if (eq->sk_flags & SK_SEARCHNULL)
-                                       {
-                                               so->qual_ok = false;
-                                               return;
-                                       }
-
                                        if (_bt_compare_scankey_args(scan, chk, eq, chk,
                                                                                                 &test_result))
                                        {
@@ -484,23 +512,6 @@ _bt_preprocess_keys(IndexScanDesc scan)
                else
                {
                        /* yup, keep only the more restrictive key */
-
-                       /* if either arg is NULL, don't try to compare */
-                       if ((cur->sk_flags | xform[j]->sk_flags) & SK_ISNULL)
-                       {
-                               /* at least one of them must be an IS NULL clause */
-                               Assert(j == (BTEqualStrategyNumber - 1));
-                               Assert((cur->sk_flags | xform[j]->sk_flags) & SK_SEARCHNULL);
-                               /* if one is and one isn't, the search must fail */
-                               if ((cur->sk_flags ^ xform[j]->sk_flags) & SK_SEARCHNULL)
-                               {
-                                       so->qual_ok = false;
-                                       return;
-                               }
-                               /* we have duplicate IS NULL clauses, ignore the newer one */
-                               continue;
-                       }
-
                        if (_bt_compare_scankey_args(scan, cur, cur, xform[j],
                                                                                 &test_result))
                        {
@@ -534,8 +545,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
 }
 
 /*
- * Compare two scankey values using a specified operator.  Both values
- * must be already known non-NULL.
+ * Compare two scankey values using a specified operator.
  *
  * The test we want to perform is logically "leftarg op rightarg", where
  * leftarg and rightarg are the sk_argument values in those ScanKeys, and
@@ -555,8 +565,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
  *
  * Note: this routine needs to be insensitive to any DESC option applied
  * to the index column.  For example, "x < 4" is a tighter constraint than
- * "x < 5" regardless of which way the index is sorted.  We don't worry about
- * NULLS FIRST/LAST either, since the given values are never nulls.
+ * "x < 5" regardless of which way the index is sorted.
  */
 static bool
 _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
@@ -571,6 +580,64 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
                                cmp_op;
        StrategyNumber strat;
 
+       /*
+        * First, deal with cases where one or both args are NULL.  This should
+        * only happen when the scankeys represent IS NULL/NOT NULL conditions.
+        */
+       if ((leftarg->sk_flags | rightarg->sk_flags) & SK_ISNULL)
+       {
+               bool            leftnull,
+                                       rightnull;
+
+               if (leftarg->sk_flags & SK_ISNULL)
+               {
+                       Assert(leftarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
+                       leftnull = true;
+               }
+               else
+                       leftnull = false;
+               if (rightarg->sk_flags & SK_ISNULL)
+               {
+                       Assert(rightarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
+                       rightnull = true;
+               }
+               else
+                       rightnull = false;
+
+               /*
+                * We treat NULL as either greater than or less than all other values.
+                * Since true > false, the tests below work correctly for NULLS LAST
+                * logic.  If the index is NULLS FIRST, we need to flip the strategy.
+                */
+               strat = op->sk_strategy;
+               if (op->sk_flags & SK_BT_NULLS_FIRST)
+                       strat = BTCommuteStrategyNumber(strat);
+
+               switch (strat)
+               {
+                       case BTLessStrategyNumber:
+                               *result = (leftnull < rightnull);
+                               break;
+                       case BTLessEqualStrategyNumber:
+                               *result = (leftnull <= rightnull);
+                               break;
+                       case BTEqualStrategyNumber:
+                               *result = (leftnull == rightnull);
+                               break;
+                       case BTGreaterEqualStrategyNumber:
+                               *result = (leftnull >= rightnull);
+                               break;
+                       case BTGreaterStrategyNumber:
+                               *result = (leftnull > rightnull);
+                               break;
+                       default:
+                               elog(ERROR, "unrecognized StrategyNumber: %d", (int) strat);
+                               *result = false;                /* keep compiler quiet */
+                               break;
+               }
+               return true;
+       }
+
        /*
         * The opfamily we need to worry about is identified by the index column.
         */
@@ -844,11 +911,18 @@ _bt_checkkeys(IndexScanDesc scan,
 
                if (key->sk_flags & SK_ISNULL)
                {
-                       /* Handle IS NULL tests */
-                       Assert(key->sk_flags & SK_SEARCHNULL);
-
-                       if (isNull)
-                               continue;               /* tuple satisfies this qual */
+                       /* Handle IS NULL/NOT NULL tests */
+                       if (key->sk_flags & SK_SEARCHNULL)
+                       {
+                               if (isNull)
+                                       continue;               /* tuple satisfies this qual */
+                       }
+                       else
+                       {
+                               Assert(key->sk_flags & SK_SEARCHNOTNULL);
+                               if (!isNull)
+                                       continue;               /* tuple satisfies this qual */
+                       }
 
                        /*
                         * Tuple fails this qual.  If it's a required qual for the current
index b136825dc8f9694dc7ded6003583dcce8dd3f697..df877ae191ec3627b9db4154e5cc78c697dab993 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.136 2009/10/26 02:26:31 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeIndexscan.c,v 1.137 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -640,7 +640,8 @@ ExecInitIndexScan(IndexScan *node, EState *estate, int eflags)
  * (Note that we treat all array-expressions as requiring runtime evaluation,
  * even if they happen to be constants.)
  *
- * 5. NullTest ("indexkey IS NULL").  We just fill in the ScanKey properly.
+ * 5. NullTest ("indexkey IS NULL/IS NOT NULL").  We just fill in the
+ * ScanKey properly.
  *
  * Input params are:
  *
@@ -987,13 +988,14 @@ ExecIndexBuildScanKeys(PlanState *planstate, Relation index, Index scanrelid,
                }
                else if (IsA(clause, NullTest))
                {
-                       /* indexkey IS NULL */
-                       Assert(((NullTest *) clause)->nulltesttype == IS_NULL);
+                       /* indexkey IS NULL or indexkey IS NOT NULL */
+                       NullTest   *ntest = (NullTest *) clause;
+                       int                     flags;
 
                        /*
                         * argument should be the index key Var, possibly relabeled
                         */
-                       leftop = ((NullTest *) clause)->arg;
+                       leftop = ntest->arg;
 
                        if (leftop && IsA(leftop, RelabelType))
                                leftop = ((RelabelType *) leftop)->arg;
@@ -1009,8 +1011,23 @@ ExecIndexBuildScanKeys(PlanState *planstate, Relation index, Index scanrelid,
                        /*
                         * initialize the scan key's fields appropriately
                         */
+                       switch (ntest->nulltesttype)
+                       {
+                               case IS_NULL:
+                                       flags = SK_ISNULL | SK_SEARCHNULL;
+                                       break;
+                               case IS_NOT_NULL:
+                                       flags = SK_ISNULL | SK_SEARCHNOTNULL;
+                                       break;
+                               default:
+                                       elog(ERROR, "unrecognized nulltesttype: %d",
+                                                (int) ntest->nulltesttype);
+                                       flags = 0;      /* keep compiler quiet */
+                                       break;
+                       }
+
                        ScanKeyEntryInitialize(this_scan_key,
-                                                                  SK_ISNULL | SK_SEARCHNULL,
+                                                                  flags,
                                                                   varattno,    /* attribute number to scan */
                                                                   InvalidStrategy,             /* no strategy */
                                                                   InvalidOid,  /* no strategy subtype */
index 7bb5d8993cc20c9dd48b060026a0ea090e74716a..456a5b9be48316d2a43fa69d069d5502671ce6d3 100644 (file)
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.242 2009/09/17 20:49:28 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.243 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1218,7 +1218,7 @@ match_clause_to_indexcol(IndexOptInfo *index,
         * Clause must be a binary opclause, or possibly a ScalarArrayOpExpr
         * (which is always binary, by definition).  Or it could be a
         * RowCompareExpr, which we pass off to match_rowcompare_to_indexcol().
-        * Or, if the index supports it, we can handle IS NULL clauses.
+        * Or, if the index supports it, we can handle IS NULL/NOT NULL clauses.
         */
        if (is_opclause(clause))
        {
@@ -1256,8 +1256,7 @@ match_clause_to_indexcol(IndexOptInfo *index,
        {
                NullTest   *nt = (NullTest *) clause;
 
-               if (nt->nulltesttype == IS_NULL &&
-                       match_index_to_operand((Node *) nt->arg, indexcol, index))
+               if (match_index_to_operand((Node *) nt->arg, indexcol, index))
                        return true;
                return false;
        }
index 43b0c123ca21ad1051b207642c5c6bf6eb500490..c8d7a28d622dd3b9f817daf83db14c557f4cb7a7 100644 (file)
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.268 2009/12/29 20:11:45 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/optimizer/plan/createplan.c,v 1.269 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -73,7 +73,6 @@ static MergeJoin *create_mergejoin_plan(PlannerInfo *root, MergePath *best_path,
 static HashJoin *create_hashjoin_plan(PlannerInfo *root, HashPath *best_path,
                                         Plan *outer_plan, Plan *inner_plan);
 static List *fix_indexqual_references(List *indexquals, IndexPath *index_path);
-static Node *fix_indexqual_operand(Node *node, IndexOptInfo *index);
 static List *get_switched_clauses(List *clauses, Relids outerrelids);
 static List *order_qual_clauses(PlannerInfo *root, List *clauses);
 static void copy_path_costsize(Plan *dest, Path *src);
@@ -2117,7 +2116,6 @@ fix_indexqual_references(List *indexquals, IndexPath *index_path)
                {
                        NullTest   *nt = (NullTest *) clause;
 
-                       Assert(nt->nulltesttype == IS_NULL);
                        nt->arg = (Expr *) fix_indexqual_operand((Node *) nt->arg,
                                                                                                         index);
                }
@@ -2131,7 +2129,13 @@ fix_indexqual_references(List *indexquals, IndexPath *index_path)
        return fixed_indexquals;
 }
 
-static Node *
+/*
+ * fix_indexqual_operand
+ *       Convert an indexqual expression to a Var referencing the index column.
+ *
+ * This is exported because planagg.c needs it.
+ */
+Node *
 fix_indexqual_operand(Node *node, IndexOptInfo *index)
 {
        /*
index 2b7934b686fce34c6edcab49ce5ed51420fb64b5..a32a06fc28dd5535cc7d5b317bd627b5ec44b55c 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/optimizer/plan/planagg.c,v 1.47 2009/12/15 17:57:46 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/optimizer/plan/planagg.c,v 1.48 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -37,7 +37,7 @@ typedef struct
        Oid                     aggfnoid;               /* pg_proc Oid of the aggregate */
        Oid                     aggsortop;              /* Oid of its sort operator */
        Expr       *target;                     /* expression we are aggregating on */
-       Expr       *notnulltest;        /* expression for "target IS NOT NULL" */
+       NullTest   *notnulltest;        /* expression for "target IS NOT NULL" */
        IndexPath  *path;                       /* access path for index scan */
        Cost            pathcost;               /* estimated cost to fetch first row */
        bool            nulls_first;    /* null ordering direction matching index */
@@ -308,7 +308,7 @@ build_minmax_path(PlannerInfo *root, RelOptInfo *rel, MinMaxAggInfo *info)
        ntest = makeNode(NullTest);
        ntest->nulltesttype = IS_NOT_NULL;
        ntest->arg = copyObject(info->target);
-       info->notnulltest = (Expr *) ntest;
+       info->notnulltest = ntest;
 
        /*
         * Build list of existing restriction clauses plus the notnull test. We
@@ -475,7 +475,7 @@ make_agg_subplan(PlannerInfo *root, MinMaxAggInfo *info)
        PlannerInfo subroot;
        Query      *subparse;
        Plan       *plan;
-       Plan       *iplan;
+       IndexScan  *iplan;
        TargetEntry *tle;
        SortGroupClause *sortcl;
 
@@ -529,16 +529,13 @@ make_agg_subplan(PlannerInfo *root, MinMaxAggInfo *info)
         *
         * Also we must add a "WHERE target IS NOT NULL" restriction to the
         * indexscan, to be sure we don't return a NULL, which'd be contrary to
-        * the standard behavior of MIN/MAX.  XXX ideally this should be done
-        * earlier, so that the selectivity of the restriction could be included
-        * in our cost estimates.  But that looks painful, and in most cases the
-        * fraction of NULLs isn't high enough to change the decision.
+        * the standard behavior of MIN/MAX.
         *
         * The NOT NULL qual has to go on the actual indexscan; create_plan might
         * have stuck a gating Result atop that, if there were any pseudoconstant
         * quals.
         *
-        * We can skip adding the NOT NULL qual if it's redundant with either an
+        * We can skip adding the NOT NULL qual if it duplicates either an
         * already-given WHERE condition, or a clause of the index predicate.
         */
        plan = create_plan(&subroot, (Path *) info->path);
@@ -546,14 +543,27 @@ make_agg_subplan(PlannerInfo *root, MinMaxAggInfo *info)
        plan->targetlist = copyObject(subparse->targetList);
 
        if (IsA(plan, Result))
-               iplan = plan->lefttree;
+               iplan = (IndexScan *) plan->lefttree;
        else
-               iplan = plan;
-       Assert(IsA(iplan, IndexScan));
+               iplan = (IndexScan *) plan;
+       if (!IsA(iplan, IndexScan))
+               elog(ERROR, "result of create_plan(IndexPath) isn't an IndexScan");
 
-       if (!list_member(iplan->qual, info->notnulltest) &&
+       if (!list_member(iplan->indexqualorig, info->notnulltest) &&
                !list_member(info->path->indexinfo->indpred, info->notnulltest))
-               iplan->qual = lcons(info->notnulltest, iplan->qual);
+       {
+               NullTest   *ntest;
+
+               /* Need a "fixed" copy as well as the original */
+               ntest = copyObject(info->notnulltest);
+               ntest->arg = (Expr *) fix_indexqual_operand((Node *) ntest->arg,
+                                                                                                       info->path->indexinfo);
+
+               iplan->indexqual = lappend(iplan->indexqual,
+                                                                  ntest);
+               iplan->indexqualorig = lappend(iplan->indexqualorig,
+                                                                          info->notnulltest);
+       }
 
        plan = (Plan *) make_limit(plan,
                                                           subparse->limitOffset,
index 8bc26cb6e97a93d25f38a7a0b804d05b35e481ca..56e3a085974e7308402a643f5b7d8c89ddfcec9b 100644 (file)
@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.264 2009/12/29 20:11:45 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.265 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -5614,7 +5614,7 @@ btcostestimate(PG_FUNCTION_ARGS)
        int                     indexcol;
        bool            eqQualHere;
        bool            found_saop;
-       bool            found_null_op;
+       bool            found_is_null_op;
        double          num_sa_scans;
        ListCell   *l;
 
@@ -5639,7 +5639,7 @@ btcostestimate(PG_FUNCTION_ARGS)
        indexcol = 0;
        eqQualHere = false;
        found_saop = false;
-       found_null_op = false;
+       found_is_null_op = false;
        num_sa_scans = 1;
        foreach(l, indexQuals)
        {
@@ -5680,12 +5680,14 @@ btcostestimate(PG_FUNCTION_ARGS)
                {
                        NullTest   *nt = (NullTest *) clause;
 
-                       Assert(nt->nulltesttype == IS_NULL);
                        leftop = (Node *) nt->arg;
                        rightop = NULL;
                        clause_op = InvalidOid;
-                       found_null_op = true;
-                       is_null_op = true;
+                       if (nt->nulltesttype == IS_NULL)
+                       {
+                               found_is_null_op = true;
+                               is_null_op = true;
+                       }
                }
                else
                {
@@ -5725,12 +5727,7 @@ btcostestimate(PG_FUNCTION_ARGS)
                        }
                }
                /* check for equality operator */
-               if (is_null_op)
-               {
-                       /* IS NULL is like = for purposes of selectivity determination */
-                       eqQualHere = true;
-               }
-               else
+               if (OidIsValid(clause_op))
                {
                        op_strategy = get_op_opfamily_strategy(clause_op,
                                                                                                   index->opfamily[indexcol]);
@@ -5738,6 +5735,11 @@ btcostestimate(PG_FUNCTION_ARGS)
                        if (op_strategy == BTEqualStrategyNumber)
                                eqQualHere = true;
                }
+               else if (is_null_op)
+               {
+                       /* IS NULL is like = for purposes of selectivity determination */
+                       eqQualHere = true;
+               }
                /* count up number of SA scans induced by indexBoundQuals only */
                if (IsA(clause, ScalarArrayOpExpr))
                {
@@ -5760,7 +5762,7 @@ btcostestimate(PG_FUNCTION_ARGS)
                indexcol == index->ncolumns - 1 &&
                eqQualHere &&
                !found_saop &&
-               !found_null_op)
+               !found_is_null_op)
                numIndexTuples = 1.0;
        else
        {
index d295d3d12d56d0a27affd5e475c42325b1559bef..509e1d08ddb416cbe9d9dcf412a725bbfb0c1deb 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/skey.h,v 1.37 2009/01/01 17:23:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/skey.h,v 1.38 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -52,11 +52,13 @@ typedef uint16 StrategyNumber;
  * the operator.  When using a ScanKey in a heap scan, these fields are not
  * used and may be set to InvalidStrategy/InvalidOid.
  *
- * A ScanKey can also represent a condition "column IS NULL"; this is signaled
- * by the SK_SEARCHNULL flag bit.  In this case the argument is always NULL,
+ * A ScanKey can also represent a condition "column IS NULL" or "column
+ * IS NOT NULL"; these cases are signaled by the SK_SEARCHNULL and
+ * SK_SEARCHNOTNULL flag bits respectively.  The argument is always NULL,
  * and the sk_strategy, sk_subtype, and sk_func fields are not used (unless
- * set by the index AM).  Currently, SK_SEARCHNULL is supported only for
- * index scans, not heap scans; and not all index AMs support it.
+ * set by the index AM).  Currently, SK_SEARCHNULL and SK_SEARCHNOTNULL are
+ * supported only for index scans, not heap scans; and not all index AMs
+ * support them.
  *
  * Note: in some places, ScanKeys are used as a convenient representation
  * for the invocation of an access method support procedure.  In this case
@@ -112,12 +114,13 @@ typedef ScanKeyData *ScanKey;
  * bits should be defined here).  Bits 16-31 are reserved for use within
  * individual index access methods.
  */
-#define SK_ISNULL              0x0001  /* sk_argument is NULL */
-#define SK_UNARY               0x0002  /* unary operator (currently unsupported) */
-#define SK_ROW_HEADER  0x0004  /* row comparison header (see above) */
-#define SK_ROW_MEMBER  0x0008  /* row comparison member (see above) */
-#define SK_ROW_END             0x0010  /* last row comparison member (see above) */
-#define SK_SEARCHNULL  0x0020  /* scankey represents a "col IS NULL" qual */
+#define SK_ISNULL                      0x0001  /* sk_argument is NULL */
+#define SK_UNARY                       0x0002  /* unary operator (not supported!) */
+#define SK_ROW_HEADER          0x0004  /* row comparison header (see above) */
+#define SK_ROW_MEMBER          0x0008  /* row comparison member (see above) */
+#define SK_ROW_END                     0x0010  /* last row comparison member */
+#define SK_SEARCHNULL          0x0020  /* scankey represents "col IS NULL" */
+#define SK_SEARCHNOTNULL       0x0040  /* scankey represents "col IS NOT NULL" */
 
 
 /*
index a92c1f49971061d19afd8f508df99b33766b1cda..1b3769fdbf55d399a88cc5e87ae0d330a20b775b 100644 (file)
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_am.h,v 1.62 2009/03/24 20:17:15 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_am.h,v 1.63 2010/01/01 21:53:49 tgl Exp $
  *
  * NOTES
  *             the genbki.sh script reads this file and generates .bki
@@ -46,7 +46,7 @@ CATALOG(pg_am,2601)
        bool            amcanmulticol;  /* does AM support multi-column indexes? */
        bool            amoptionalkey;  /* can query omit key for the first column? */
        bool            amindexnulls;   /* does AM support NULL index entries? */
-       bool            amsearchnulls;  /* can AM search for NULL index entries? */
+       bool            amsearchnulls;  /* can AM search for NULL/NOT NULL entries? */
        bool            amstorage;              /* can storage type differ from column type? */
        bool            amclusterable;  /* does AM support cluster command? */
        Oid                     amkeytype;              /* type of data in index, or InvalidOid */
index 8738a9924d553d6f9d30a612e1035e54cf24833d..fbbec6d574478d6dc9d1de94f82066436413e97c 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.180 2009/11/28 00:46:19 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.181 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -459,7 +459,7 @@ typedef struct IndexOptInfo
        bool            predOK;                 /* true if predicate matches query */
        bool            unique;                 /* true if a unique index */
        bool            amoptionalkey;  /* can query omit key for the first column? */
-       bool            amsearchnulls;  /* can AM search for NULL index entries? */
+       bool            amsearchnulls;  /* can AM search for NULL/NOT NULL entries? */
        bool            amhasgettuple;  /* does AM have amgettuple interface? */
        bool            amhasgetbitmap; /* does AM have amgetbitmap interface? */
 } IndexOptInfo;
index 9a661a5ee8cb3f8d30c4ff0be1e2a11d04382512..2e9f0659f26c8927e20e2de51de0af1db1d0e657 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/optimizer/planmain.h,v 1.121 2009/10/26 02:26:45 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/planmain.h,v 1.122 2010/01/01 21:53:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -39,6 +39,7 @@ extern Plan *optimize_minmax_aggregates(PlannerInfo *root, List *tlist,
  * prototypes for plan/createplan.c
  */
 extern Plan *create_plan(PlannerInfo *root, Path *best_path);
+extern Node *fix_indexqual_operand(Node *node, IndexOptInfo *index);
 extern SubqueryScan *make_subqueryscan(List *qptlist, List *qpqual,
                                  Index scanrelid, Plan *subplan,
                                  List *subrtable, List *subrowmark);
index 9dd54b39f0989ec3c6a363fac0333fdb927e3655..b67f4e06f39b8068da003c2371401102e1876b56 100644 (file)
@@ -720,7 +720,7 @@ Indexes:
 
 DROP TABLE concur_heap;
 --
--- Tests for IS NULL with b-tree indexes
+-- Tests for IS NULL/IS NOT NULL with b-tree indexes
 --
 SELECT unique1, unique2 INTO onek_with_null FROM onek;
 INSERT INTO onek_with_null (unique1,unique2) VALUES (NULL, -1), (NULL, NULL);
@@ -740,6 +740,18 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
      1
 (1 row)
 
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+ count 
+-------
+  1000
+(1 row)
+
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
+ count 
+-------
+     1
+(1 row)
+
 DROP INDEX onek_nulltest;
 CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2 desc,unique1);
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
@@ -754,6 +766,18 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
      1
 (1 row)
 
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+ count 
+-------
+  1000
+(1 row)
+
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
+ count 
+-------
+     1
+(1 row)
+
 DROP INDEX onek_nulltest;
 CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2 desc nulls last,unique1);
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
@@ -768,6 +792,18 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
      1
 (1 row)
 
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+ count 
+-------
+  1000
+(1 row)
+
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
+ count 
+-------
+     1
+(1 row)
+
 DROP INDEX onek_nulltest;
 CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2  nulls first,unique1);
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
@@ -782,6 +818,18 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
      1
 (1 row)
 
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+ count 
+-------
+  1000
+(1 row)
+
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
+ count 
+-------
+     1
+(1 row)
+
 RESET enable_seqscan;
 RESET enable_indexscan;
 RESET enable_bitmapscan;
index b205afa34f7455cda710b8e3616a749a60d95deb..519c3181a84d29da11949e16ab8d46ece2e8c55c 100644 (file)
@@ -322,7 +322,7 @@ COMMIT;
 DROP TABLE concur_heap;
 
 --
--- Tests for IS NULL with b-tree indexes
+-- Tests for IS NULL/IS NOT NULL with b-tree indexes
 --
 
 SELECT unique1, unique2 INTO onek_with_null FROM onek;
@@ -335,6 +335,8 @@ SET enable_bitmapscan = ON;
 
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
 
 DROP INDEX onek_nulltest;
 
@@ -342,6 +344,8 @@ CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2 desc,unique1);
 
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
 
 DROP INDEX onek_nulltest;
 
@@ -349,6 +353,8 @@ CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2 desc nulls last,uni
 
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
 
 DROP INDEX onek_nulltest;
 
@@ -356,6 +362,8 @@ CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2  nulls first,unique
 
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
 SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
+SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
 
 RESET enable_seqscan;
 RESET enable_indexscan;