]> granicus.if.org Git - postgresql/commitdiff
Improve handling of NULLs in KNN-GiST and KNN-SP-GiST
authorAlexander Korotkov <akorotkov@postgresql.org>
Thu, 19 Sep 2019 18:30:19 +0000 (21:30 +0300)
committerAlexander Korotkov <akorotkov@postgresql.org>
Thu, 19 Sep 2019 18:48:39 +0000 (21:48 +0300)
This commit improves subject in two ways:

 * It removes ugliness of 02f90879e7, which stores distance values and null
   flags in two separate arrays after GISTSearchItem struct.  Instead we pack
   both distance value and null flag in IndexOrderByDistance struct.  Alignment
   overhead should be negligible, because we typically deal with at most few
   "col op const" expressions in ORDER BY clause.
 * It fixes handling of "col op NULL" expression in KNN-SP-GiST.  Now, these
   expression are not passed to support functions, which can't deal with them.
   Instead, NULL result is implicitly assumed.  It future we may decide to
   teach support functions to deal with NULL arguments, but current solution is
   bugfix suitable for backpatch.

Reported-by: Nikita Glukhov
Discussion: https://postgr.es/m/826f57ee-afc7-8977-c44c-6111d18b02ec%40postgrespro.ru
Author: Nikita Glukhov
Reviewed-by: Alexander Korotkov
Backpatch-through: 9.4

src/backend/access/gist/gistget.c
src/backend/access/gist/gistscan.c
src/backend/access/index/indexam.c
src/backend/access/spgist/spgscan.c
src/include/access/genam.h
src/include/access/gist_private.h
src/include/access/spgist_private.h
src/test/regress/expected/create_index_spgist.out
src/test/regress/sql/create_index_spgist.sql
src/tools/pgindent/typedefs.list

index db633a94757ddc64d7e5f89ca841ad02de9927c6..22d790d8221480e935d3b99c3858fbf5d7c0da90 100644 (file)
@@ -112,9 +112,8 @@ gistkillitems(IndexScanDesc scan)
  * Similarly, *recheck_distances_p is set to indicate whether the distances
  * need to be rechecked, and it is also ignored for non-leaf entries.
  *
- * If we are doing an ordered scan, so->distancesValues[] and
- * so->distancesNulls[] is filled with distance data from the distance()
- * functions before returning success.
+ * If we are doing an ordered scan, so->distances[] is filled with distance
+ * data from the distance() functions before returning success.
  *
  * We must decompress the key in the IndexTuple before passing it to the
  * sk_funcs (which actually are the opclass Consistent or Distance methods).
@@ -135,8 +134,7 @@ gistindex_keytest(IndexScanDesc scan,
        GISTSTATE  *giststate = so->giststate;
        ScanKey         key = scan->keyData;
        int                     keySize = scan->numberOfKeys;
-       double     *distance_value_p;
-       bool       *distance_null_p;
+       IndexOrderByDistance *distance_p;
        Relation        r = scan->indexRelation;
 
        *recheck_p = false;
@@ -155,8 +153,8 @@ gistindex_keytest(IndexScanDesc scan,
                        elog(ERROR, "invalid GiST tuple found on leaf page");
                for (i = 0; i < scan->numberOfOrderBys; i++)
                {
-                       so->distanceValues[i] = -get_float8_infinity();
-                       so->distanceNulls[i] = false;
+                       so->distances[i].value = -get_float8_infinity();
+                       so->distances[i].isnull = false;
                }
                return true;
        }
@@ -240,8 +238,7 @@ gistindex_keytest(IndexScanDesc scan,
 
        /* OK, it passes --- now let's compute the distances */
        key = scan->orderByData;
-       distance_value_p = so->distanceValues;
-       distance_null_p = so->distanceNulls;
+       distance_p = so->distances;
        keySize = scan->numberOfOrderBys;
        while (keySize > 0)
        {
@@ -256,8 +253,8 @@ gistindex_keytest(IndexScanDesc scan,
                if ((key->sk_flags & SK_ISNULL) || isNull)
                {
                        /* Assume distance computes as null */
-                       *distance_value_p = 0.0;
-                       *distance_null_p = true;
+                       distance_p->value = 0.0;
+                       distance_p->isnull = true;
                }
                else
                {
@@ -294,13 +291,12 @@ gistindex_keytest(IndexScanDesc scan,
                                                                         ObjectIdGetDatum(key->sk_subtype),
                                                                         PointerGetDatum(&recheck));
                        *recheck_distances_p |= recheck;
-                       *distance_value_p = DatumGetFloat8(dist);
-                       *distance_null_p = false;
+                       distance_p->value = DatumGetFloat8(dist);
+                       distance_p->isnull = false;
                }
 
                key++;
-               distance_value_p++;
-               distance_null_p++;
+               distance_p++;
                keySize--;
        }
 
@@ -313,8 +309,7 @@ gistindex_keytest(IndexScanDesc scan,
  *
  * scan: index scan we are executing
  * pageItem: search queue item identifying an index page to scan
- * myDistanceValues: distances array associated with pageItem, or NULL at the root
- * myDistanceNulls: null flags for myDistanceValues array, or NULL at the root
+ * myDistances: distances array associated with pageItem, or NULL at the root
  * tbm: if not NULL, gistgetbitmap's output bitmap
  * ntids: if not NULL, gistgetbitmap's output tuple counter
  *
@@ -332,8 +327,7 @@ gistindex_keytest(IndexScanDesc scan,
  */
 static void
 gistScanPage(IndexScanDesc scan, GISTSearchItem *pageItem,
-                        double *myDistanceValues, bool *myDistanceNulls,
-                        TIDBitmap *tbm, int64 *ntids)
+                        IndexOrderByDistance *myDistances, TIDBitmap *tbm, int64 *ntids)
 {
        GISTScanOpaque so = (GISTScanOpaque) scan->opaque;
        GISTSTATE  *giststate = so->giststate;
@@ -370,7 +364,7 @@ gistScanPage(IndexScanDesc scan, GISTSearchItem *pageItem,
                GISTSearchItem *item;
 
                /* This can't happen when starting at the root */
-               Assert(myDistanceValues != NULL && myDistanceNulls != NULL);
+               Assert(myDistances != NULL);
 
                oldcxt = MemoryContextSwitchTo(so->queueCxt);
 
@@ -380,10 +374,8 @@ gistScanPage(IndexScanDesc scan, GISTSearchItem *pageItem,
                item->data.parentlsn = pageItem->data.parentlsn;
 
                /* Insert it into the queue using same distances as for this page */
-               memcpy(GISTSearchItemDistanceValues(item, scan->numberOfOrderBys),
-                          myDistanceValues, sizeof(double) * scan->numberOfOrderBys);
-               memcpy(GISTSearchItemDistanceNulls(item, scan->numberOfOrderBys),
-                          myDistanceNulls, sizeof(bool) * scan->numberOfOrderBys);
+               memcpy(item->distances, myDistances,
+                          sizeof(item->distances[0]) * scan->numberOfOrderBys);
 
                pairingheap_add(so->queue, &item->phNode);
 
@@ -527,10 +519,8 @@ gistScanPage(IndexScanDesc scan, GISTSearchItem *pageItem,
                        }
 
                        /* Insert it into the queue using new distance data */
-                       memcpy(GISTSearchItemDistanceValues(item, nOrderBys),
-                                  so->distanceValues, sizeof(double) * nOrderBys);
-                       memcpy(GISTSearchItemDistanceNulls(item, nOrderBys),
-                                  so->distanceNulls, sizeof(bool) * nOrderBys);
+                       memcpy(item->distances, so->distances,
+                                  sizeof(item->distances[0]) * nOrderBys);
 
                        pairingheap_add(so->queue, &item->phNode);
 
@@ -595,8 +585,7 @@ getNextNearest(IndexScanDesc scan)
                        scan->xs_recheck = item->data.heap.recheck;
 
                        index_store_float8_orderby_distances(scan, so->orderByTypes,
-                                                                                                GISTSearchItemDistanceValues(item, scan->numberOfOrderBys),
-                                                                                                GISTSearchItemDistanceNulls(item, scan->numberOfOrderBys),
+                                                                                                item->distances,
                                                                                                 item->data.heap.recheckDistances);
 
                        /* in an index-only scan, also return the reconstructed tuple. */
@@ -609,10 +598,7 @@ getNextNearest(IndexScanDesc scan)
                        /* visit an index page, extract its items into queue */
                        CHECK_FOR_INTERRUPTS();
 
-                       gistScanPage(scan, item,
-                                                GISTSearchItemDistanceValues(item, scan->numberOfOrderBys),
-                                                GISTSearchItemDistanceNulls(item, scan->numberOfOrderBys),
-                                                NULL, NULL);
+                       gistScanPage(scan, item, item->distances, NULL, NULL);
                }
 
                pfree(item);
@@ -650,7 +636,7 @@ gistgettuple(IndexScanDesc scan, ScanDirection dir)
 
                fakeItem.blkno = GIST_ROOT_BLKNO;
                memset(&fakeItem.data.parentlsn, 0, sizeof(GistNSN));
-               gistScanPage(scan, &fakeItem, NULL, NULL, NULL, NULL);
+               gistScanPage(scan, &fakeItem, NULL, NULL, NULL);
        }
 
        if (scan->numberOfOrderBys > 0)
@@ -744,10 +730,7 @@ gistgettuple(IndexScanDesc scan, ScanDirection dir)
                                 * this page, we fall out of the inner "do" and loop around to
                                 * return them.
                                 */
-                               gistScanPage(scan, item,
-                                                        GISTSearchItemDistanceValues(item, scan->numberOfOrderBys),
-                                                        GISTSearchItemDistanceNulls(item, scan->numberOfOrderBys),
-                                                        NULL, NULL);
+                               gistScanPage(scan, item, item->distances, NULL, NULL);
 
                                pfree(item);
                        } while (so->nPageData == 0);
@@ -778,7 +761,7 @@ gistgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 
        fakeItem.blkno = GIST_ROOT_BLKNO;
        memset(&fakeItem.data.parentlsn, 0, sizeof(GistNSN));
-       gistScanPage(scan, &fakeItem, NULL, NULL, tbm, &ntids);
+       gistScanPage(scan, &fakeItem, NULL, tbm, &ntids);
 
        /*
         * While scanning a leaf page, ItemPointers of matching heap tuples will
@@ -793,10 +776,7 @@ gistgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 
                CHECK_FOR_INTERRUPTS();
 
-               gistScanPage(scan, item,
-                                        GISTSearchItemDistanceValues(item, scan->numberOfOrderBys),
-                                        GISTSearchItemDistanceNulls(item, scan->numberOfOrderBys),
-                                        tbm, &ntids);
+               gistScanPage(scan, item, item->distances, tbm, &ntids);
 
                pfree(item);
        }
index e72bf08f952b578aa3261ba7bf8296b0f5da1b54..7d0d3524bb6320c8c1fb7d781dd27e4071895696 100644 (file)
@@ -33,26 +33,23 @@ pairingheap_GISTSearchItem_cmp(const pairingheap_node *a, const pairingheap_node
        const GISTSearchItem *sb = (const GISTSearchItem *) b;
        IndexScanDesc scan = (IndexScanDesc) arg;
        int                     i;
-       double     *da = GISTSearchItemDistanceValues(sa, scan->numberOfOrderBys),
-                          *db = GISTSearchItemDistanceValues(sb, scan->numberOfOrderBys);
-       bool       *na = GISTSearchItemDistanceNulls(sa, scan->numberOfOrderBys),
-                          *nb = GISTSearchItemDistanceNulls(sb, scan->numberOfOrderBys);
 
        /* Order according to distance comparison */
        for (i = 0; i < scan->numberOfOrderBys; i++)
        {
-               if (na[i])
+               if (sa->distances[i].isnull)
                {
-                       if (!nb[i])
+                       if (!sb->distances[i].isnull)
                                return -1;
                }
-               else if (nb[i])
+               else if (sb->distances[i].isnull)
                {
                        return 1;
                }
                else
                {
-                       int                     cmp = -float8_cmp_internal(da[i], db[i]);
+                       int                     cmp = -float8_cmp_internal(sa->distances[i].value,
+                                                                                                  sb->distances[i].value);
 
                        if (cmp != 0)
                                return cmp;
@@ -100,8 +97,7 @@ gistbeginscan(Relation r, int nkeys, int norderbys)
        so->queueCxt = giststate->scanCxt;      /* see gistrescan */
 
        /* workspaces with size dependent on numberOfOrderBys: */
-       so->distanceValues = palloc(sizeof(double) * scan->numberOfOrderBys);
-       so->distanceNulls = palloc(sizeof(bool) * scan->numberOfOrderBys);
+       so->distances = palloc(sizeof(so->distances[0]) * scan->numberOfOrderBys);
        so->qual_ok = true;                     /* in case there are zero keys */
        if (scan->numberOfOrderBys > 0)
        {
index 2e8f53a37c8463f6bd73ca1f25d323a318495dca..442f41425d4b85325c095dfca0d90f122a90dd36 100644 (file)
@@ -847,14 +847,14 @@ index_getprocinfo(Relation irel,
  */
 void
 index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
-                                                                        double *distanceValues,
-                                                                        bool *distanceNulls, bool recheckOrderBy)
+                                                                        IndexOrderByDistance *distances,
+                                                                        bool recheckOrderBy)
 {
        int                     i;
 
        scan->xs_recheckorderby = recheckOrderBy;
 
-       if (!distanceValues)
+       if (!distances)
        {
                Assert(!scan->xs_recheckorderby);
 
@@ -869,11 +869,11 @@ index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
 
        for (i = 0; i < scan->numberOfOrderBys; i++)
        {
-               if (distanceNulls && distanceNulls[i])
-               {
+               scan->xs_orderbynulls[i] = distances[i].isnull;
+
+               if (scan->xs_orderbynulls[i])
                        scan->xs_orderbyvals[i] = (Datum) 0;
-                       scan->xs_orderbynulls[i] = true;
-               }
+
                if (orderByTypes[i] == FLOAT8OID)
                {
 #ifndef USE_FLOAT8_BYVAL
@@ -881,8 +881,8 @@ index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
                        if (!scan->xs_orderbynulls[i])
                                pfree(DatumGetPointer(scan->xs_orderbyvals[i]));
 #endif
-                       scan->xs_orderbyvals[i] = Float8GetDatum(distanceValues[i]);
-                       scan->xs_orderbynulls[i] = false;
+                       if (!scan->xs_orderbynulls[i])
+                               scan->xs_orderbyvals[i] = Float8GetDatum(distances[i].value);
                }
                else if (orderByTypes[i] == FLOAT4OID)
                {
@@ -892,8 +892,8 @@ index_store_float8_orderby_distances(IndexScanDesc scan, Oid *orderByTypes,
                        if (!scan->xs_orderbynulls[i])
                                pfree(DatumGetPointer(scan->xs_orderbyvals[i]));
 #endif
-                       scan->xs_orderbyvals[i] = Float4GetDatum((float4) distanceValues[i]);
-                       scan->xs_orderbynulls[i] = false;
+                       if (!scan->xs_orderbynulls[i])
+                               scan->xs_orderbyvals[i] = Float4GetDatum((float4) distances[i].value);
                }
                else
                {
index 2bd4037af9e00c837680b4e79cca3b050b1bb5f5..cfba47067cc15f14cc0df0befe0fead35394d448 100644 (file)
@@ -107,13 +107,13 @@ spgAllocSearchItem(SpGistScanOpaque so, bool isnull, double *distances)
 {
        /* allocate distance array only for non-NULL items */
        SpGistSearchItem *item =
-       palloc(SizeOfSpGistSearchItem(isnull ? 0 : so->numberOfOrderBys));
+       palloc(SizeOfSpGistSearchItem(isnull ? 0 : so->numberOfNonNullOrderBys));
 
        item->isNull = isnull;
 
-       if (!isnull && so->numberOfOrderBys > 0)
+       if (!isnull && so->numberOfNonNullOrderBys > 0)
                memcpy(item->distances, distances,
-                          so->numberOfOrderBys * sizeof(double));
+                          sizeof(item->distances[0]) * so->numberOfNonNullOrderBys);
 
        return item;
 }
@@ -208,6 +208,34 @@ spgPrepareScanKeys(IndexScanDesc scan)
        so->numberOfOrderBys = scan->numberOfOrderBys;
        so->orderByData = scan->orderByData;
 
+       if (so->numberOfOrderBys <= 0)
+               so->numberOfNonNullOrderBys = 0;
+       else
+       {
+               int                     j = 0;
+
+               /*
+                * Remove all NULL keys, but remember their offsets in the original
+                * array.
+                */
+               for (i = 0; i < scan->numberOfOrderBys; i++)
+               {
+                       ScanKey         skey = &so->orderByData[i];
+
+                       if (skey->sk_flags & SK_ISNULL)
+                               so->nonNullOrderByOffsets[i] = -1;
+                       else
+                       {
+                               if (i != j)
+                                       so->orderByData[j] = *skey;
+
+                               so->nonNullOrderByOffsets[i] = j++;
+                       }
+               }
+
+               so->numberOfNonNullOrderBys = j;
+       }
+
        if (scan->numberOfKeys <= 0)
        {
                /* If no quals, whole-index scan is required */
@@ -295,6 +323,8 @@ spgbeginscan(Relation rel, int keysz, int orderbysz)
                /* This will be filled in spgrescan, but allocate the space here */
                so->orderByTypes = (Oid *)
                        palloc(sizeof(Oid) * scan->numberOfOrderBys);
+               so->nonNullOrderByOffsets = (int *)
+                       palloc(sizeof(int) * scan->numberOfOrderBys);
 
                /* These arrays have constant contents, so we can fill them now */
                so->zeroDistances = (double *)
@@ -394,6 +424,7 @@ spgendscan(IndexScanDesc scan)
        if (scan->numberOfOrderBys > 0)
        {
                pfree(so->orderByTypes);
+               pfree(so->nonNullOrderByOffsets);
                pfree(so->zeroDistances);
                pfree(so->infDistances);
                pfree(scan->xs_orderbyvals);
@@ -465,7 +496,7 @@ spgLeafTest(SpGistScanOpaque so, SpGistSearchItem *item,
                in.scankeys = so->keyData;
                in.nkeys = so->numberOfKeys;
                in.orderbys = so->orderByData;
-               in.norderbys = so->numberOfOrderBys;
+               in.norderbys = so->numberOfNonNullOrderBys;
                in.reconstructedValue = item->value;
                in.traversalValue = item->traversalValue;
                in.level = item->level;
@@ -492,7 +523,7 @@ spgLeafTest(SpGistScanOpaque so, SpGistSearchItem *item,
        if (result)
        {
                /* item passes the scankeys */
-               if (so->numberOfOrderBys > 0)
+               if (so->numberOfNonNullOrderBys > 0)
                {
                        /* the scan is ordered -> add the item to the queue */
                        MemoryContext oldCxt = MemoryContextSwitchTo(so->traversalCxt);
@@ -531,7 +562,7 @@ spgInitInnerConsistentIn(spgInnerConsistentIn *in,
        in->scankeys = so->keyData;
        in->orderbys = so->orderByData;
        in->nkeys = so->numberOfKeys;
-       in->norderbys = so->numberOfOrderBys;
+       in->norderbys = so->numberOfNonNullOrderBys;
        in->reconstructedValue = item->value;
        in->traversalMemoryContext = so->traversalCxt;
        in->traversalValue = item->traversalValue;
@@ -751,7 +782,7 @@ redirect:
                if (item->isLeaf)
                {
                        /* We store heap items in the queue only in case of ordered search */
-                       Assert(so->numberOfOrderBys > 0);
+                       Assert(so->numberOfNonNullOrderBys > 0);
                        storeRes(so, &item->heapPtr, item->value, item->isNull,
                                         item->recheck, item->recheckDistances, item->distances);
                        reportedSome = true;
@@ -874,7 +905,7 @@ spggetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 static void
 storeGettuple(SpGistScanOpaque so, ItemPointer heapPtr,
                          Datum leafValue, bool isnull, bool recheck, bool recheckDistances,
-                         double *distances)
+                         double *nonNullDistances)
 {
        Assert(so->nPtrs < MaxIndexTuplesPerPage);
        so->heapPtrs[so->nPtrs] = *heapPtr;
@@ -883,13 +914,33 @@ storeGettuple(SpGistScanOpaque so, ItemPointer heapPtr,
 
        if (so->numberOfOrderBys > 0)
        {
-               if (isnull)
+               if (isnull || so->numberOfNonNullOrderBys <= 0)
                        so->distances[so->nPtrs] = NULL;
                else
                {
-                       Size            size = sizeof(double) * so->numberOfOrderBys;
+                       IndexOrderByDistance *distances =
+                       palloc(sizeof(distances[0]) * so->numberOfOrderBys);
+                       int                     i;
+
+                       for (i = 0; i < so->numberOfOrderBys; i++)
+                       {
+                               int                     offset = so->nonNullOrderByOffsets[i];
+
+                               if (offset >= 0)
+                               {
+                                       /* Copy non-NULL distance value */
+                                       distances[i].value = nonNullDistances[offset];
+                                       distances[i].isnull = false;
+                               }
+                               else
+                               {
+                                       /* Set distance's NULL flag. */
+                                       distances[i].value = 0.0;
+                                       distances[i].isnull = true;
+                               }
+                       }
 
-                       so->distances[so->nPtrs] = memcpy(palloc(size), distances, size);
+                       so->distances[so->nPtrs] = distances;
                }
        }
 
@@ -929,7 +980,6 @@ spggettuple(IndexScanDesc scan, ScanDirection dir)
                        if (so->numberOfOrderBys > 0)
                                index_store_float8_orderby_distances(scan, so->orderByTypes,
                                                                                                         so->distances[so->iPtr],
-                                                                                                        NULL,
                                                                                                         so->recheckDistances[so->iPtr]);
                        so->iPtr++;
                        return true;
index 6c56717ba77600faef0f5e342be34f750df5c5ef..a813b004be7d797d8ed264e5b8a6941dcad2dc78 100644 (file)
@@ -118,6 +118,13 @@ typedef enum IndexUniqueCheck
 } IndexUniqueCheck;
 
 
+/* Nullable "ORDER BY col op const" distance */
+typedef struct IndexOrderByDistance
+{
+       double          value;
+       bool            isnull;
+} IndexOrderByDistance;
+
 /*
  * generalized index_ interface routines (in indexam.c)
  */
@@ -179,8 +186,7 @@ extern FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attnum,
                                                                   uint16 procnum);
 extern void index_store_float8_orderby_distances(IndexScanDesc scan,
                                                                                                 Oid *orderByTypes,
-                                                                                                double *distanceValues,
-                                                                                                bool *distanceNulls,
+                                                                                                IndexOrderByDistance *distances,
                                                                                                 bool recheckOrderBy);
 
 /*
index ed5b643885dcc94c559d5d29ef518b67c1cf3b82..ab134c1a3940453339ad6b50acfa1fd5a0a57e06 100644 (file)
@@ -138,29 +138,15 @@ typedef struct GISTSearchItem
                GISTSearchHeapItem heap;        /* heap info, if heap tuple */
        }                       data;
 
-       /*
-        * This data structure is followed by arrays of distance values and
-        * distance null flags.  Size of both arrays is
-        * IndexScanDesc->numberOfOrderBys. See macros below for accessing those
-        * arrays.
-        */
+       /* numberOfOrderBys entries */
+       IndexOrderByDistance distances[FLEXIBLE_ARRAY_MEMBER];
 } GISTSearchItem;
 
 #define GISTSearchItemIsHeap(item)     ((item).blkno == InvalidBlockNumber)
 
-#define SizeOfGISTSearchItem(n_distances) (DOUBLEALIGN(sizeof(GISTSearchItem)) + \
-       (sizeof(double) + sizeof(bool)) * (n_distances))
-
-/*
- * We actually don't need n_distances compute pointer to distance values.
- * Nevertheless take n_distances as argument to have same arguments list for
- * GISTSearchItemDistanceValues() and GISTSearchItemDistanceNulls().
- */
-#define GISTSearchItemDistanceValues(item, n_distances) \
-       ((double *) ((Pointer) (item) + DOUBLEALIGN(sizeof(GISTSearchItem))))
-
-#define GISTSearchItemDistanceNulls(item, n_distances) \
-       ((bool *) ((Pointer) (item) + DOUBLEALIGN(sizeof(GISTSearchItem)) + sizeof(double) * (n_distances)))
+#define SizeOfGISTSearchItem(n_distances) \
+       (offsetof(GISTSearchItem, distances) + \
+        sizeof(IndexOrderByDistance) * (n_distances))
 
 /*
  * GISTScanOpaqueData: private state for a scan of a GiST index
@@ -176,8 +162,7 @@ typedef struct GISTScanOpaqueData
        bool            firstCall;              /* true until first gistgettuple call */
 
        /* pre-allocated workspace arrays */
-       double     *distanceValues; /* output area for gistindex_keytest */
-       bool       *distanceNulls;
+       IndexOrderByDistance *distances;        /* output area for gistindex_keytest */
 
        /* info about killed items if any (killedItems is NULL if never used) */
        OffsetNumber *killedItems;      /* offset numbers of killed items */
index e0d1178f24572801a9b33f87274ee8c126ac9a14..428e54bfbd2fc4b4c11e9bd60173175250b1de5e 100644 (file)
@@ -169,8 +169,12 @@ typedef struct SpGistScanOpaqueData
        int                     numberOfKeys;   /* number of index qualifier conditions */
        ScanKey         keyData;                /* array of index qualifier descriptors */
        int                     numberOfOrderBys;       /* number of ordering operators */
+       int                     numberOfNonNullOrderBys;        /* number of ordering operators
+                                                                                        * with non-NULL arguments */
        ScanKey         orderByData;    /* array of ordering op descriptors */
        Oid                *orderByTypes;       /* array of ordering op return types */
+       int                *nonNullOrderByOffsets;      /* array of offset of non-NULL
+                                                                                * ordering keys in the original array */
        Oid                     indexCollation; /* collation of index column */
 
        /* Opclass defined functions: */
@@ -195,7 +199,9 @@ typedef struct SpGistScanOpaqueData
        bool            recheckDistances[MaxIndexTuplesPerPage];        /* distance recheck
                                                                                                                         * flags */
        HeapTuple       reconTups[MaxIndexTuplesPerPage];       /* reconstructed tuples */
-       double     *distances[MaxIndexTuplesPerPage];   /* distances (for recheck) */
+
+       /* distances (for recheck) */
+       IndexOrderByDistance *distances[MaxIndexTuplesPerPage];
 
        /*
         * Note: using MaxIndexTuplesPerPage above is a bit hokey since
index 81b4a67c3909e59c0e58165d049644c510662716..5ccea915867703a5178d194a4da2c73b87f5a984 100644 (file)
@@ -555,6 +555,16 @@ WHERE seq.dist IS DISTINCT FROM idx.dist;
 ---+------+---+---+------+---
 (0 rows)
 
+-- check ORDER BY distance to NULL
+SELECT (SELECT p FROM kd_point_tbl ORDER BY p <-> pt LIMIT 1)
+FROM (VALUES (point '1,2'), (NULL), ('1234,5678')) pts(pt);
+      p      
+-------------
+ (59,21)
+ (9853,112)
+ (1239,5647)
+(3 rows)
+
 EXPLAIN (COSTS OFF)
 SELECT count(*) FROM radix_text_tbl WHERE t = 'P0123456789abcdef';
                          QUERY PLAN                         
index 8e6c453307675d9b19bc648a7ff05c4687b8ac67..629936fd3d49d24bf13791804c7e0fe3baee7892 100644 (file)
@@ -225,6 +225,11 @@ SELECT * FROM quad_point_tbl_ord_seq3 seq FULL JOIN kd_point_tbl_ord_idx3 idx
 ON seq.n = idx.n
 WHERE seq.dist IS DISTINCT FROM idx.dist;
 
+-- check ORDER BY distance to NULL
+SELECT (SELECT p FROM kd_point_tbl ORDER BY p <-> pt LIMIT 1)
+FROM (VALUES (point '1,2'), (NULL), ('1234,5678')) pts(pt);
+
+
 EXPLAIN (COSTS OFF)
 SELECT count(*) FROM radix_text_tbl WHERE t = 'P0123456789abcdef';
 SELECT count(*) FROM radix_text_tbl WHERE t = 'P0123456789abcdef';
index f3cdfa8a223f639c1857a1a66c57a9845479c8d9..fb652651750a49032e8a62b402f0a3606b24c2b4 100644 (file)
@@ -1043,6 +1043,7 @@ IndexList
 IndexOnlyScan
 IndexOnlyScanState
 IndexOptInfo
+IndexOrderByDistance
 IndexPath
 IndexRuntimeKeyInfo
 IndexScan