diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index d4d1fe45cc1..6ddbadb2abd 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1753,6 +1753,23 @@ include_dir 'conf.d'
+
+ hashagg_mem_overflow (boolean)
+
+ hashagg_mem_overflow configuration parameter
+
+
+
+
+ If hash aggregation exceeds work_mem at query
+ execution time, and hashagg_mem_overflow is set
+ to on, continue consuming more memory rather than
+ performing disk-based hash aggregation. The default
+ is off.
+
+
+
+
max_stack_depth (integer)
@@ -4453,6 +4470,24 @@ ANY num_sync (
+ enable_hashagg_spill (boolean)
+
+ enable_hashagg_spill configuration parameter
+
+
+
+
+ Enables or disables the query planner's use of hashed aggregation plan
+ types when the memory usage is expected to
+ exceed work_mem. This only affects the planner
+ choice; actual behavior at execution time is dictated by
+ . The default
+ is on.
+
+
+
+
enable_hashjoin (boolean)
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 62fb3434a32..092a79ea14f 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -102,6 +102,7 @@ static void show_tablesample(TableSampleClause *tsc, PlanState *planstate,
List *ancestors, ExplainState *es);
static void show_sort_info(SortState *sortstate, ExplainState *es);
static void show_hash_info(HashState *hashstate, ExplainState *es);
+static void show_hashagg_info(AggState *hashstate, ExplainState *es);
static void show_tidbitmap_info(BitmapHeapScanState *planstate,
ExplainState *es);
static void show_instrumentation_count(const char *qlabel, int which,
@@ -1826,6 +1827,8 @@ ExplainNode(PlanState *planstate, List *ancestors,
case T_Agg:
show_agg_keys(castNode(AggState, planstate), ancestors, es);
show_upper_qual(plan->qual, "Filter", planstate, ancestors, es);
+ if (es->analyze)
+ show_hashagg_info((AggState *) planstate, es);
if (plan->qual)
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
@@ -2715,6 +2718,56 @@ show_hash_info(HashState *hashstate, ExplainState *es)
}
}
+/*
+ * If EXPLAIN ANALYZE, show information on hash aggregate memory usage and
+ * batches.
+ */
+static void
+show_hashagg_info(AggState *aggstate, ExplainState *es)
+{
+ Agg *agg = (Agg *)aggstate->ss.ps.plan;
+ long memPeakKb = (aggstate->hash_mem_peak + 1023) / 1024;
+ long diskKb = (aggstate->hash_disk_used + 1023) / 1024;
+
+
+ Assert(IsA(aggstate, AggState));
+
+ if (agg->aggstrategy != AGG_HASHED &&
+ agg->aggstrategy != AGG_MIXED)
+ return;
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ {
+ appendStringInfoSpaces(es->str, es->indent * 2);
+ appendStringInfo(
+ es->str,
+ "Memory Usage: %ldkB",
+ memPeakKb);
+
+ if (aggstate->hash_batches_used > 0)
+ {
+ appendStringInfo(
+ es->str,
+ " Batches: %d Disk Usage:%ldkB",
+ aggstate->hash_batches_used, diskKb);
+ }
+
+ appendStringInfo(
+ es->str,
+ "\n");
+ }
+ else
+ {
+ ExplainPropertyInteger("Peak Memory Usage", "kB", memPeakKb, es);
+ if (aggstate->hash_batches_used > 0)
+ {
+ ExplainPropertyInteger("HashAgg Batches", NULL,
+ aggstate->hash_batches_used, es);
+ ExplainPropertyInteger("Disk Usage", "kB", diskKb, es);
+ }
+ }
+}
+
/*
* If it's EXPLAIN ANALYZE, show exact/lossy pages for a BitmapHeapScan node
*/
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index dbed5978162..07ac8e96fdf 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -1603,14 +1603,14 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
{
AggState *aggstate;
AggStatePerGroup pergroup;
+ AggStatePerGroup pergroup_allaggs;
aggstate = op->d.agg_init_trans.aggstate;
- pergroup = &aggstate->all_pergroups
- [op->d.agg_init_trans.setoff]
- [op->d.agg_init_trans.transno];
+ pergroup_allaggs = aggstate->all_pergroups[op->d.agg_init_trans.setoff];
+ pergroup = &pergroup_allaggs[op->d.agg_init_trans.transno];
/* If transValue has not yet been initialized, do so now. */
- if (pergroup->noTransValue)
+ if (pergroup_allaggs != NULL && pergroup->noTransValue)
{
AggStatePerTrans pertrans = op->d.agg_init_trans.pertrans;
@@ -1631,13 +1631,14 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
{
AggState *aggstate;
AggStatePerGroup pergroup;
+ AggStatePerGroup pergroup_allaggs;
aggstate = op->d.agg_strict_trans_check.aggstate;
- pergroup = &aggstate->all_pergroups
- [op->d.agg_strict_trans_check.setoff]
- [op->d.agg_strict_trans_check.transno];
+ pergroup_allaggs = aggstate->all_pergroups[op->d.agg_strict_trans_check.setoff];
+ pergroup = &pergroup_allaggs[op->d.agg_strict_trans_check.transno];
- if (unlikely(pergroup->transValueIsNull))
+ if (pergroup_allaggs == NULL ||
+ unlikely(pergroup->transValueIsNull))
EEO_JUMP(op->d.agg_strict_trans_check.jumpnull);
EEO_NEXT();
@@ -1653,6 +1654,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
AggState *aggstate;
AggStatePerTrans pertrans;
AggStatePerGroup pergroup;
+ AggStatePerGroup pergroup_allaggs;
FunctionCallInfo fcinfo;
MemoryContext oldContext;
Datum newVal;
@@ -1660,9 +1662,11 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
aggstate = op->d.agg_trans.aggstate;
pertrans = op->d.agg_trans.pertrans;
- pergroup = &aggstate->all_pergroups
- [op->d.agg_trans.setoff]
- [op->d.agg_trans.transno];
+ pergroup_allaggs = aggstate->all_pergroups[op->d.agg_trans.setoff];
+ pergroup = &pergroup_allaggs[op->d.agg_trans.transno];
+
+ if (pergroup_allaggs == NULL)
+ EEO_NEXT();
Assert(pertrans->transtypeByVal);
@@ -1704,6 +1708,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
AggState *aggstate;
AggStatePerTrans pertrans;
AggStatePerGroup pergroup;
+ AggStatePerGroup pergroup_allaggs;
FunctionCallInfo fcinfo;
MemoryContext oldContext;
Datum newVal;
@@ -1711,9 +1716,11 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
aggstate = op->d.agg_trans.aggstate;
pertrans = op->d.agg_trans.pertrans;
- pergroup = &aggstate->all_pergroups
- [op->d.agg_trans.setoff]
- [op->d.agg_trans.transno];
+ pergroup_allaggs = aggstate->all_pergroups[op->d.agg_trans.setoff];
+ pergroup = &pergroup_allaggs[op->d.agg_trans.transno];
+
+ if (pergroup_allaggs == NULL)
+ EEO_NEXT();
Assert(!pertrans->transtypeByVal);
diff --git a/src/backend/executor/execGrouping.c b/src/backend/executor/execGrouping.c
index 7bc5e405bcc..7c831831b5d 100644
--- a/src/backend/executor/execGrouping.c
+++ b/src/backend/executor/execGrouping.c
@@ -25,7 +25,6 @@
#include "utils/lsyscache.h"
#include "utils/memutils.h"
-static uint32 TupleHashTableHash(struct tuplehash_hash *tb, const MinimalTuple tuple);
static int TupleHashTableMatch(struct tuplehash_hash *tb, const MinimalTuple tuple1, const MinimalTuple tuple2);
/*
@@ -299,6 +298,28 @@ ResetTupleHashTable(TupleHashTable hashtable)
TupleHashEntry
LookupTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
bool *isnew)
+{
+ MemoryContext oldContext;
+ uint32 hash;
+
+ /* Need to run the hash functions in short-lived context */
+ oldContext = MemoryContextSwitchTo(hashtable->tempcxt);
+
+ /* set up data needed by hash and match functions */
+ hashtable->inputslot = slot;
+ hashtable->in_hash_funcs = hashtable->tab_hash_funcs;
+ hashtable->cur_eq_func = hashtable->tab_eq_func;
+
+ hash = TupleHashTableHash(hashtable->hashtab, NULL);
+
+ MemoryContextSwitchTo(oldContext);
+
+ return LookupTupleHashEntryHash(hashtable, slot, isnew, hash);
+}
+
+TupleHashEntry
+LookupTupleHashEntryHash(TupleHashTable hashtable, TupleTableSlot *slot,
+ bool *isnew, uint32 hash)
{
TupleHashEntryData *entry;
MemoryContext oldContext;
@@ -317,7 +338,7 @@ LookupTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
if (isnew)
{
- entry = tuplehash_insert(hashtable->hashtab, key, &found);
+ entry = tuplehash_insert_hash(hashtable->hashtab, key, hash, &found);
if (found)
{
@@ -337,7 +358,7 @@ LookupTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
}
else
{
- entry = tuplehash_lookup(hashtable->hashtab, key);
+ entry = tuplehash_lookup_hash(hashtable->hashtab, key, hash);
}
MemoryContextSwitchTo(oldContext);
@@ -382,17 +403,12 @@ FindTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
/*
* Compute the hash value for a tuple
*
- * The passed-in key is a pointer to TupleHashEntryData. In an actual hash
- * table entry, the firstTuple field points to a tuple (in MinimalTuple
- * format). LookupTupleHashEntry sets up a dummy TupleHashEntryData with a
- * NULL firstTuple field --- that cues us to look at the inputslot instead.
- * This convention avoids the need to materialize virtual input tuples unless
- * they actually need to get copied into the table.
+ * If tuple is NULL, use the input slot instead.
*
* Also, the caller must select an appropriate memory context for running
* the hash functions. (dynahash.c doesn't change CurrentMemoryContext.)
*/
-static uint32
+uint32
TupleHashTableHash(struct tuplehash_hash *tb, const MinimalTuple tuple)
{
TupleHashTable hashtable = (TupleHashTable) tb->private_data;
@@ -413,9 +429,6 @@ TupleHashTableHash(struct tuplehash_hash *tb, const MinimalTuple tuple)
{
/*
* Process a tuple already stored in the table.
- *
- * (this case never actually occurs due to the way simplehash.h is
- * used, as the hash-value is stored in the entries)
*/
slot = hashtable->tableslot;
ExecStoreMinimalTuple(tuple, slot, false);
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 6ee24eab3d2..a70151cf7da 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -194,6 +194,18 @@
* transition values. hashcontext is the single context created to support
* all hash tables.
*
+ * When the hash table memory exceeds work_mem, we advance the transition
+ * states only for groups already in the hash table. For tuples that would
+ * need to create a new hash table entries (and initialize new transition
+ * states), we spill them to disk to be processed later. The tuples are
+ * spilled in a partitioned manner, so that subsequent batches are smaller
+ * and less likely to exceed work_mem (if a batch does exceed work_mem, it
+ * must be spilled recursively).
+ *
+ * Note that it's possible for transition states to start small but then
+ * grow very large; for instance in the case of ARRAY_AGG. In such cases,
+ * it's still possible to significantly exceed work_mem.
+ *
* Transition / Combine function invocation:
*
* For performance reasons transition functions, including combine
@@ -229,15 +241,65 @@
#include "optimizer/optimizer.h"
#include "parser/parse_agg.h"
#include "parser/parse_coerce.h"
+#include "storage/buffile.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datum.h"
+#include "utils/dynahash.h"
#include "utils/expandeddatum.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/syscache.h"
#include "utils/tuplesort.h"
+/*
+ * Control how many partitions are created when spilling HashAgg to
+ * disk.
+ *
+ * HASH_PARTITION_FACTOR is multiplied by the estimated number of partitions
+ * needed such that each partition will fit in memory. The factor is set
+ * higher than one because there's not a high cost to having a few too many
+ * partitions, and it makes it less likely that a partition will need to be
+ * spilled recursively. Another benefit of having more, smaller partitions is
+ * that small hash tables may perform better than large ones due to memory
+ * caching effects.
+ *
+ * HASH_PARTITION_MEM is the approximate amount of work_mem we should reserve
+ * for the partitions themselves (i.e. buffering of the files backing the
+ * partitions). This is an estimate, because we choose the number of
+ * partitions at the time we need to spill, and because this algorithm
+ * shouldn't depend too directly on the internal memory needs of a BufFile.
+ */
+#define HASH_PARTITION_FACTOR 1.50
+#define HASH_MIN_PARTITIONS 4
+#define HASH_MAX_PARTITIONS 256
+#define HASH_PARTITION_MEM (HASH_MIN_PARTITIONS * BLCKSZ)
+
+/*
+ * Represents partitioned spill data for a single hashtable.
+ */
+typedef struct HashAggSpill
+{
+ int n_partitions; /* number of output partitions */
+ int partition_bits; /* number of bits for partition mask
+ log2(n_partitions) parent partition bits */
+ BufFile **partitions; /* output partition files */
+ int64 *ntuples; /* number of tuples in each partition */
+} HashAggSpill;
+
+/*
+ * Represents work to be done for one pass of hash aggregation. Initially,
+ * only the input fields are set. If spilled to disk, also set the spill data.
+ */
+typedef struct HashAggBatch
+{
+ BufFile *input_file; /* input partition */
+ int input_bits; /* number of bits for input partition mask */
+ int64 input_groups; /* estimated number of input groups */
+ int setno; /* grouping set */
+ HashAggSpill spill; /* spill output */
+} HashAggBatch;
+
static void select_current_set(AggState *aggstate, int setno, bool is_hash);
static void initialize_phase(AggState *aggstate, int newphase);
static TupleTableSlot *fetch_input_tuple(AggState *aggstate);
@@ -272,11 +334,27 @@ static TupleTableSlot *project_aggregates(AggState *aggstate);
static Bitmapset *find_unaggregated_cols(AggState *aggstate);
static bool find_unaggregated_cols_walker(Node *node, Bitmapset **colnos);
static void build_hash_table(AggState *aggstate);
-static TupleHashEntryData *lookup_hash_entry(AggState *aggstate);
+static void prepare_hash_slot(AggState *aggstate);
+static uint32 calculate_hash(AggState *aggstate);
+static AggStatePerGroup lookup_hash_entry(AggState *aggstate, uint32 hash);
static void lookup_hash_entries(AggState *aggstate);
static TupleTableSlot *agg_retrieve_direct(AggState *aggstate);
static void agg_fill_hash_table(AggState *aggstate);
+static bool agg_refill_hash_table(AggState *aggstate);
static TupleTableSlot *agg_retrieve_hash_table(AggState *aggstate);
+static TupleTableSlot *agg_retrieve_hash_table_in_memory(AggState *aggstate);
+static void hash_spill_init(HashAggSpill *spill, int input_bits,
+ uint64 input_tuples, double hashentrysize);
+static Size hash_spill_tuple(HashAggSpill *spill, int input_bits,
+ TupleTableSlot *slot, uint32 hash);
+static MinimalTuple hash_read_spilled(BufFile *file, uint32 *hashp);
+static HashAggBatch *hash_batch_new(BufFile *input_file, int setno,
+ int64 input_groups, int input_bits);
+static void hash_finish_initial_spills(AggState *aggstate);
+static void hash_spill_finish(AggState *aggstate, HashAggSpill *spill,
+ int setno, int input_bits);
+static void hash_reset_spill(HashAggSpill *spill);
+static void hash_reset_spills(AggState *aggstate);
static Datum GetAggInitVal(Datum textInitVal, Oid transtype);
static void build_pertrans_for_aggref(AggStatePerTrans pertrans,
AggState *aggstate, EState *estate,
@@ -1269,6 +1347,10 @@ build_hash_table(AggState *aggstate)
Assert(aggstate->aggstrategy == AGG_HASHED || aggstate->aggstrategy == AGG_MIXED);
+ /* TODO: work harder to find a good nGroups for each hash table. We don't
+ * want the hash table itself to fill up work_mem with no room for
+ * out-of-line transition values. Also, we need to consider that there are
+ * multiple hash tables for grouping sets. */
additionalsize = aggstate->numtrans * sizeof(AggStatePerGroupData);
for (i = 0; i < aggstate->num_hashes; ++i)
@@ -1294,6 +1376,24 @@ build_hash_table(AggState *aggstate)
tmpmem,
DO_AGGSPLIT_SKIPFINAL(aggstate->aggsplit));
}
+
+ aggstate->hash_mem_current = MemoryContextMemAllocated(
+ aggstate->hashcontext->ecxt_per_tuple_memory, true);
+ aggstate->hash_ngroups_current = 0;
+
+ /*
+ * Initialize the threshold at which we stop creating new hash entries and
+ * start spilling. If an empty hash table exceeds the limit, increase the
+ * limit to be the size of the empty hash table. This ensures that at
+ * least one entry can be added so that the algorithm can make progress.
+ */
+ if (hashagg_mem_overflow)
+ aggstate->hash_mem_limit = SIZE_MAX;
+ else
+ aggstate->hash_mem_limit = (work_mem * 1024L) - HASH_PARTITION_MEM;
+
+ if (aggstate->hash_mem_current > aggstate->hash_mem_limit)
+ aggstate->hash_mem_limit = aggstate->hash_mem_current;
}
/*
@@ -1454,23 +1554,13 @@ hash_agg_entry_size(int numAggs)
return entrysize;
}
-/*
- * Find or create a hashtable entry for the tuple group containing the current
- * tuple (already set in tmpcontext's outertuple slot), in the current grouping
- * set (which the caller must have selected - note that initialize_aggregate
- * depends on this).
- *
- * When called, CurrentMemoryContext should be the per-query context.
- */
-static TupleHashEntryData *
-lookup_hash_entry(AggState *aggstate)
+static void
+prepare_hash_slot(AggState *aggstate)
{
- TupleTableSlot *inputslot = aggstate->tmpcontext->ecxt_outertuple;
- AggStatePerHash perhash = &aggstate->perhash[aggstate->current_set];
- TupleTableSlot *hashslot = perhash->hashslot;
- TupleHashEntryData *entry;
- bool isnew;
- int i;
+ TupleTableSlot *inputslot = aggstate->tmpcontext->ecxt_outertuple;
+ AggStatePerHash perhash = &aggstate->perhash[aggstate->current_set];
+ TupleTableSlot *hashslot = perhash->hashslot;
+ int i;
/* transfer just the needed columns into hashslot */
slot_getsomeattrs(inputslot, perhash->largestGrpColIdx);
@@ -1484,14 +1574,71 @@ lookup_hash_entry(AggState *aggstate)
hashslot->tts_isnull[i] = inputslot->tts_isnull[varNumber];
}
ExecStoreVirtualTuple(hashslot);
+}
+
+static uint32
+calculate_hash(AggState *aggstate)
+{
+ AggStatePerHash perhash = &aggstate->perhash[aggstate->current_set];
+ TupleHashTable hashtable = perhash->hashtable;
+ MemoryContext oldContext;
+ uint32 hash;
+
+ /* set up data needed by hash and match functions */
+ hashtable->inputslot = perhash->hashslot;
+ hashtable->in_hash_funcs = hashtable->tab_hash_funcs;
+ hashtable->cur_eq_func = hashtable->tab_eq_func;
+
+ /* Need to run the hash functions in short-lived context */
+ oldContext = MemoryContextSwitchTo(hashtable->tempcxt);
+
+ hash = TupleHashTableHash(hashtable->hashtab, NULL);
+
+ MemoryContextSwitchTo(oldContext);
+
+ return hash;
+}
+
+/*
+ * Find or create a hashtable entry for the tuple group containing the current
+ * tuple (already set in tmpcontext's outertuple slot), in the current grouping
+ * set (which the caller must have selected - note that initialize_aggregate
+ * depends on this).
+ *
+ * When called, CurrentMemoryContext should be the per-query context.
+ */
+static AggStatePerGroup
+lookup_hash_entry(AggState *aggstate, uint32 hash)
+{
+ AggStatePerHash perhash = &aggstate->perhash[aggstate->current_set];
+ TupleTableSlot *hashslot = perhash->hashslot;
+ TupleHashEntryData *entry;
+ bool isnew = false;
+ bool *p_isnew;
+
+ /* if hash table memory limit is exceeded, don't create new entries */
+ p_isnew = (aggstate->hash_mem_current > aggstate->hash_mem_limit) ?
+ NULL : &isnew;
/* find or create the hashtable entry using the filtered tuple */
- entry = LookupTupleHashEntry(perhash->hashtable, hashslot, &isnew);
+ entry = LookupTupleHashEntryHash(perhash->hashtable, hashslot, p_isnew,
+ hash);
+
+ if (entry == NULL)
+ return NULL;
if (isnew)
{
- AggStatePerGroup pergroup;
- int transno;
+ AggStatePerGroup pergroup;
+ int transno;
+
+ aggstate->hash_ngroups_current++;
+
+ aggstate->hash_mem_current = MemoryContextMemAllocated(
+ aggstate->hashcontext->ecxt_per_tuple_memory, true);
+
+ if (aggstate->hash_mem_current > aggstate->hash_mem_peak)
+ aggstate->hash_mem_peak = aggstate->hash_mem_current;
pergroup = (AggStatePerGroup)
MemoryContextAlloc(perhash->hashtable->tablecxt,
@@ -1511,7 +1658,7 @@ lookup_hash_entry(AggState *aggstate)
}
}
- return entry;
+ return entry->additional;
}
/*
@@ -1519,18 +1666,49 @@ lookup_hash_entry(AggState *aggstate)
* returning an array of pergroup pointers suitable for advance_aggregates.
*
* Be aware that lookup_hash_entry can reset the tmpcontext.
+ *
+ * Return false if hash table has exceeded its memory limit.
*/
static void
lookup_hash_entries(AggState *aggstate)
{
- int numHashes = aggstate->num_hashes;
AggStatePerGroup *pergroup = aggstate->hash_pergroup;
int setno;
- for (setno = 0; setno < numHashes; setno++)
+ for (setno = 0; setno < aggstate->num_hashes; setno++)
{
+ AggStatePerHash perhash = &aggstate->perhash[setno];
+ uint32 hash;
+
select_current_set(aggstate, setno, true);
- pergroup[setno] = lookup_hash_entry(aggstate)->additional;
+ prepare_hash_slot(aggstate);
+ hash = calculate_hash(aggstate);
+ pergroup[setno] = lookup_hash_entry(aggstate, hash);
+
+ if (pergroup[setno] == NULL)
+ {
+ HashAggSpill *spill;
+ TupleTableSlot *slot = aggstate->tmpcontext->ecxt_outertuple;
+ double hashentrysize = 0;
+
+ /* average memory cost per entry */
+ if (aggstate->hash_ngroups_current > 0)
+ hashentrysize = (double)aggstate->hash_mem_current /
+ (double)aggstate->hash_ngroups_current;
+
+ if (aggstate->hash_spills == NULL)
+ aggstate->hash_spills = palloc0(
+ sizeof(HashAggSpill) * aggstate->num_hashes);
+ aggstate->hash_spilled = true;
+
+ spill = &aggstate->hash_spills[setno];
+
+ if (spill->partitions == NULL)
+ hash_spill_init(spill, 0, perhash->aggnode->numGroups,
+ hashentrysize);
+
+ aggstate->hash_disk_used += hash_spill_tuple(spill, 0, slot, hash);
+ }
}
}
@@ -1852,6 +2030,10 @@ agg_retrieve_direct(AggState *aggstate)
outerslot = fetch_input_tuple(aggstate);
if (TupIsNull(outerslot))
{
+ if (aggstate->aggstrategy == AGG_MIXED &&
+ aggstate->current_phase == 1)
+ hash_finish_initial_spills(aggstate);
+
/* no more outer-plan tuples available */
if (hasGroupingSets)
{
@@ -1955,6 +2137,8 @@ agg_fill_hash_table(AggState *aggstate)
ResetExprContext(aggstate->tmpcontext);
}
+ hash_finish_initial_spills(aggstate);
+
aggstate->table_filled = true;
/* Initialize to walk the first hash table */
select_current_set(aggstate, 0, true);
@@ -1962,11 +2146,149 @@ agg_fill_hash_table(AggState *aggstate)
&aggstate->perhash[0].hashiter);
}
+/*
+ * If any data was spilled during hash aggregation, reset the hash table and
+ * reprocess one batch of spilled data. After reprocessing a batch, the hash
+ * table will again contain data, ready to be consumed by
+ * agg_retrieve_hash_table_in_memory().
+ *
+ * Should only be called after all in memory hash table entries have been
+ * consumed.
+ *
+ * Return false when input is exhausted and there's no more work to be done;
+ * otherwise return true.
+ */
+static bool
+agg_refill_hash_table(AggState *aggstate)
+{
+ HashAggBatch *batch;
+ AggStatePerGroup *pergroup;
+
+ if (aggstate->hash_batches == NIL)
+ return false;
+
+ pergroup = aggstate->all_pergroups;
+ while(pergroup != aggstate->hash_pergroup) {
+ *pergroup = NULL;
+ pergroup++;
+ }
+
+ /* free memory */
+ ReScanExprContext(aggstate->hashcontext);
+ /* Rebuild an empty hash table */
+ build_hash_table(aggstate);
+
+ batch = linitial(aggstate->hash_batches);
+ aggstate->hash_batches = list_delete_first(aggstate->hash_batches);
+
+ Assert(aggstate->current_phase == 0);
+
+ /*
+ * TODO: what should be done here to set up for advance_aggregates?
+ */
+ if (aggstate->phase->aggstrategy == AGG_MIXED)
+ {
+ aggstate->current_phase = 1;
+ aggstate->phase = &aggstate->phases[aggstate->current_phase];
+ }
+
+ for (;;) {
+ TupleTableSlot *slot = aggstate->hash_spill_slot;
+ MinimalTuple tuple;
+ uint32 hash;
+
+ CHECK_FOR_INTERRUPTS();
+
+ tuple = hash_read_spilled(batch->input_file, &hash);
+ if (tuple == NULL)
+ break;
+
+ /*
+ * TODO: Should we re-compile the expressions to use a minimal tuple
+ * slot so that we don't have to create the virtual tuple here? If we
+ * project the tuple before writing, then perhaps this is not
+ * important.
+ */
+ ExecForceStoreMinimalTuple(tuple, slot, true);
+ aggstate->tmpcontext->ecxt_outertuple = slot;
+
+ /* Find or build hashtable entries */
+ memset(aggstate->hash_pergroup, 0,
+ sizeof(AggStatePerGroup) * aggstate->num_hashes);
+ select_current_set(aggstate, batch->setno, true);
+ prepare_hash_slot(aggstate);
+ aggstate->hash_pergroup[batch->setno] = lookup_hash_entry(aggstate, hash);
+ if (aggstate->hash_pergroup[batch->setno] == NULL)
+ {
+ double hashentrysize = 0;
+
+ /* average memory cost per entry */
+ if (aggstate->hash_ngroups_current > 0)
+ hashentrysize = (double)aggstate->hash_mem_current /
+ (double)aggstate->hash_ngroups_current;
+
+ if (batch->spill.partitions == NULL)
+ hash_spill_init(&batch->spill, batch->input_bits,
+ batch->input_groups, hashentrysize);
+
+ aggstate->hash_disk_used += hash_spill_tuple(
+ &batch->spill, batch->input_bits, slot, hash);
+ }
+
+ /* Advance the aggregates (or combine functions) */
+ advance_aggregates(aggstate);
+
+ /*
+ * Reset per-input-tuple context after each tuple, but note that the
+ * hash lookups do this too
+ */
+ ResetExprContext(aggstate->tmpcontext);
+ }
+
+ BufFileClose(batch->input_file);
+
+ aggstate->current_phase = 0;
+ aggstate->phase = &aggstate->phases[aggstate->current_phase];
+
+ hash_spill_finish(aggstate, &batch->spill, batch->setno,
+ batch->input_bits);
+
+ pfree(batch);
+
+ /* Initialize to walk the first hash table */
+ select_current_set(aggstate, 0, true);
+ ResetTupleHashIterator(aggstate->perhash[0].hashtable,
+ &aggstate->perhash[0].hashiter);
+
+ return true;
+}
+
/*
* ExecAgg for hashed case: retrieving groups from hash table
*/
static TupleTableSlot *
agg_retrieve_hash_table(AggState *aggstate)
+{
+ TupleTableSlot *result = NULL;
+
+ while (result == NULL)
+ {
+ result = agg_retrieve_hash_table_in_memory(aggstate);
+ if (result == NULL)
+ {
+ if (!agg_refill_hash_table(aggstate))
+ {
+ aggstate->agg_done = true;
+ break;
+ }
+ }
+ }
+
+ return result;
+}
+
+static TupleTableSlot *
+agg_retrieve_hash_table_in_memory(AggState *aggstate)
{
ExprContext *econtext;
AggStatePerAgg peragg;
@@ -1995,7 +2317,7 @@ agg_retrieve_hash_table(AggState *aggstate)
* We loop retrieving groups until we find one satisfying
* aggstate->ss.ps.qual
*/
- while (!aggstate->agg_done)
+ for (;;)
{
TupleTableSlot *hashslot = perhash->hashslot;
int i;
@@ -2026,8 +2348,6 @@ agg_retrieve_hash_table(AggState *aggstate)
}
else
{
- /* No more hashtables, so done */
- aggstate->agg_done = true;
return NULL;
}
}
@@ -2084,6 +2404,322 @@ agg_retrieve_hash_table(AggState *aggstate)
return NULL;
}
+/*
+ * Determine the number of partitions to create when spilling.
+ */
+static int
+hash_spill_npartitions(uint64 input_tuples, double hashentrysize)
+{
+ Size mem_needed;
+ int partition_limit;
+ int npartitions;
+
+ /*
+ * Avoid creating so many partitions that the memory requirements of the
+ * open partition files (estimated at BLCKSZ for buffering) are greater
+ * than 1/4 of work_mem.
+ */
+ partition_limit = (work_mem * 1024L * 0.25) / BLCKSZ;
+
+ /* pessimistically estimate that each input tuple creates a new group */
+ mem_needed = HASH_PARTITION_FACTOR * input_tuples * hashentrysize;
+
+ /* make enough partitions so that each one is likely to fit in memory */
+ npartitions = 1 + (mem_needed / (work_mem * 1024L));
+
+ if (npartitions > partition_limit)
+ npartitions = partition_limit;
+
+ if (npartitions < HASH_MIN_PARTITIONS)
+ npartitions = HASH_MIN_PARTITIONS;
+ if (npartitions > HASH_MAX_PARTITIONS)
+ npartitions = HASH_MAX_PARTITIONS;
+
+ return npartitions;
+}
+
+/*
+ * hash_spill_init
+ *
+ * Called after we determined that spilling is necessary. Chooses the number
+ * of partitions to create, and initializes them.
+ */
+static void
+hash_spill_init(HashAggSpill *spill, int input_bits, uint64 input_tuples,
+ double hashentrysize)
+{
+ int npartitions;
+ int partition_bits;
+
+ npartitions = hash_spill_npartitions(input_tuples, hashentrysize);
+ partition_bits = my_log2(npartitions);
+
+ /* make sure that we don't exhaust the hash bits */
+ if (partition_bits + input_bits >= 32)
+ partition_bits = 32 - input_bits;
+
+ /* number of partitions will be a power of two */
+ npartitions = 1L << partition_bits;
+
+ spill->partition_bits = partition_bits;
+ spill->n_partitions = npartitions;
+ spill->partitions = palloc0(sizeof(BufFile *) * npartitions);
+ spill->ntuples = palloc0(sizeof(int64) * npartitions);
+}
+
+/*
+ * hash_spill_tuple
+ *
+ * Not enough memory to add tuple as new entry in hash table. Save for later
+ * in the appropriate partition.
+ */
+static Size
+hash_spill_tuple(HashAggSpill *spill, int input_bits, TupleTableSlot *slot,
+ uint32 hash)
+{
+ int partition;
+ MinimalTuple tuple;
+ BufFile *file;
+ int written;
+ int total_written = 0;
+ bool shouldFree;
+
+ Assert(spill->partitions != NULL);
+
+ /*
+ * TODO: should we project only needed attributes from the tuple before
+ * writing it?
+ */
+ tuple = ExecFetchSlotMinimalTuple(slot, &shouldFree);
+
+ if (spill->partition_bits == 0)
+ partition = 0;
+ else
+ partition = (hash << input_bits) >>
+ (32 - spill->partition_bits);
+
+ spill->ntuples[partition]++;
+
+ /*
+ * TODO: use logtape.c instead?
+ */
+ if (spill->partitions[partition] == NULL)
+ spill->partitions[partition] = BufFileCreateTemp(false);
+ file = spill->partitions[partition];
+
+
+ written = BufFileWrite(file, (void *) &hash, sizeof(uint32));
+ if (written != sizeof(uint32))
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not write to HashAgg temporary file: %m")));
+ total_written += written;
+
+ written = BufFileWrite(file, (void *) tuple, tuple->t_len);
+ if (written != tuple->t_len)
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not write to HashAgg temporary file: %m")));
+ total_written += written;
+
+ if (shouldFree)
+ pfree(tuple);
+
+ return total_written;
+}
+
+/*
+ * read_spilled_tuple
+ * read the next tuple from a batch file. Return NULL if no more.
+ */
+static MinimalTuple
+hash_read_spilled(BufFile *file, uint32 *hashp)
+{
+ MinimalTuple tuple;
+ uint32 t_len;
+ size_t nread;
+ uint32 hash;
+
+ nread = BufFileRead(file, &hash, sizeof(uint32));
+ if (nread == 0)
+ return NULL;
+ if (nread != sizeof(uint32))
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not read from HashAgg temporary file: %m")));
+ if (hashp != NULL)
+ *hashp = hash;
+
+ nread = BufFileRead(file, &t_len, sizeof(t_len));
+ if (nread != sizeof(uint32))
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not read from HashAgg temporary file: %m")));
+
+ tuple = (MinimalTuple) palloc(t_len);
+ tuple->t_len = t_len;
+
+ nread = BufFileRead(file, (void *)((char *)tuple + sizeof(uint32)),
+ t_len - sizeof(uint32));
+ if (nread != t_len - sizeof(uint32))
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not read from HashAgg temporary file: %m")));
+
+ return tuple;
+}
+
+/*
+ * new_hashagg_batch
+ *
+ * Construct a HashAggBatch item, which represents one iteration of HashAgg to
+ * be done. Should be called in the aggregate's memory context.
+ */
+static HashAggBatch *
+hash_batch_new(BufFile *input_file, int setno, int64 input_groups,
+ int input_bits)
+{
+ HashAggBatch *batch = palloc0(sizeof(HashAggBatch));
+
+ batch->input_file = input_file;
+ batch->input_bits = input_bits;
+ batch->input_groups = input_groups;
+ batch->setno = setno;
+
+ /* batch->spill will be set only after spilling this batch */
+
+ return batch;
+}
+
+/*
+ * hash_finish_initial_spills
+ *
+ * After a HashAggBatch has been processed, it may have spilled tuples to
+ * disk. If so, turn the spilled partitions into new batches that must later
+ * be executed.
+ */
+static void
+hash_finish_initial_spills(AggState *aggstate)
+{
+ int setno;
+
+ if (aggstate->hash_spills == NULL)
+ return;
+
+ for (setno = 0; setno < aggstate->num_hashes; setno++)
+ hash_spill_finish(aggstate, &aggstate->hash_spills[setno], setno, 0);
+
+ pfree(aggstate->hash_spills);
+ aggstate->hash_spills = NULL;
+}
+
+/*
+ * hash_spill_finish
+ *
+ *
+ */
+static void
+hash_spill_finish(AggState *aggstate, HashAggSpill *spill, int setno, int input_bits)
+{
+ int i;
+
+ if (spill->n_partitions == 0)
+ return; /* didn't spill */
+
+ for (i = 0; i < spill->n_partitions; i++)
+ {
+ BufFile *file = spill->partitions[i];
+ MemoryContext oldContext;
+ HashAggBatch *new_batch;
+ int64 input_ngroups;
+
+ /* partition is empty */
+ if (file == NULL)
+ continue;
+
+ /* rewind file for reading */
+ if (BufFileSeek(file, 0, 0L, SEEK_SET))
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not rewind HashAgg temporary file: %m")));
+
+ /*
+ * Estimate the number of input groups for this new work item as the
+ * total number of tuples in its input file. Although that's a worst
+ * case, it's not bad here for two reasons: (1) overestimating is
+ * better than underestimating; and (2) we've already scanned the
+ * relation once, so it's likely that we've already finalized many of
+ * the common values.
+ */
+ input_ngroups = spill->ntuples[i];
+
+ oldContext = MemoryContextSwitchTo(aggstate->ss.ps.state->es_query_cxt);
+ new_batch = hash_batch_new(file, setno, input_ngroups,
+ spill->partition_bits + input_bits);
+ aggstate->hash_batches = lappend(aggstate->hash_batches, new_batch);
+ aggstate->hash_batches_used++;
+ MemoryContextSwitchTo(oldContext);
+ }
+
+ pfree(spill->ntuples);
+ pfree(spill->partitions);
+}
+
+/*
+ * Clear a HashAggSpill, free its memory, and close its files.
+ */
+static void
+hash_reset_spill(HashAggSpill *spill)
+{
+ int i;
+ for (i = 0; i < spill->n_partitions; i++)
+ {
+ BufFile *file = spill->partitions[i];
+
+ if (file != NULL)
+ BufFileClose(file);
+ }
+ if (spill->ntuples != NULL)
+ pfree(spill->ntuples);
+ if (spill->partitions != NULL)
+ pfree(spill->partitions);
+}
+
+/*
+ * Find and reset all active HashAggSpills.
+ */
+static void
+hash_reset_spills(AggState *aggstate)
+{
+ ListCell *lc;
+
+ if (aggstate->hash_spills != NULL)
+ {
+ int setno;
+
+ for (setno = 0; setno < aggstate->num_hashes; setno++)
+ hash_reset_spill(&aggstate->hash_spills[setno]);
+
+ pfree(aggstate->hash_spills);
+ aggstate->hash_spills = NULL;
+ }
+
+ foreach(lc, aggstate->hash_batches)
+ {
+ HashAggBatch *batch = (HashAggBatch*) lfirst(lc);
+ if (batch->input_file != NULL)
+ {
+ BufFileClose(batch->input_file);
+ batch->input_file = NULL;
+ }
+ hash_reset_spill(&batch->spill);
+ pfree(batch);
+ }
+ list_free(aggstate->hash_batches);
+ aggstate->hash_batches = NIL;
+}
+
+
/* -----------------
* ExecInitAgg
*
@@ -2268,6 +2904,10 @@ ExecInitAgg(Agg *node, EState *estate, int eflags)
aggstate->ss.ps.outeropsfixed = false;
}
+ if (use_hashing)
+ aggstate->hash_spill_slot = ExecInitExtraTupleSlot(estate, scanDesc,
+ &TTSOpsVirtual);
+
/*
* Initialize result type, slot and projection.
*/
@@ -3398,6 +4038,8 @@ ExecEndAgg(AggState *node)
if (node->sort_out)
tuplesort_end(node->sort_out);
+ hash_reset_spills(node);
+
for (transno = 0; transno < node->numtrans; transno++)
{
AggStatePerTrans pertrans = &node->pertrans[transno];
@@ -3453,12 +4095,13 @@ ExecReScanAgg(AggState *node)
return;
/*
- * If we do have the hash table, and the subplan does not have any
- * parameter changes, and none of our own parameter changes affect
- * input expressions of the aggregated functions, then we can just
- * rescan the existing hash table; no need to build it again.
+ * If we do have the hash table, and it never spilled, and the subplan
+ * does not have any parameter changes, and none of our own parameter
+ * changes affect input expressions of the aggregated functions, then
+ * we can just rescan the existing hash table; no need to build it
+ * again.
*/
- if (outerPlan->chgParam == NULL &&
+ if (outerPlan->chgParam == NULL && !node->hash_spilled &&
!bms_overlap(node->ss.ps.chgParam, aggnode->aggParams))
{
ResetTupleHashIterator(node->perhash[0].hashtable,
@@ -3515,6 +4158,17 @@ ExecReScanAgg(AggState *node)
*/
if (node->aggstrategy == AGG_HASHED || node->aggstrategy == AGG_MIXED)
{
+ hash_reset_spills(node);
+
+ node->hash_spilled = false;
+ node->hash_mem_current = 0;
+ node->hash_ngroups_current = 0;
+
+ /* reset stats */
+ node->hash_mem_peak = 0;
+ node->hash_disk_used = 0;
+ node->hash_batches_used = 0;
+
ReScanExprContext(node->hashcontext);
/* Rebuild an empty hash table */
build_hash_table(node);
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index a9d362100a8..f0f742eebf5 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -2093,12 +2093,14 @@ llvm_compile_expr(ExprState *state)
LLVMValueRef v_allpergroupsp;
LLVMValueRef v_pergroupp;
+ LLVMValueRef v_pergroup_allaggs;
LLVMValueRef v_setoff,
v_transno;
LLVMValueRef v_notransvalue;
+ LLVMBasicBlockRef b_check_notransvalue;
LLVMBasicBlockRef b_init;
aggstate = op->d.agg_init_trans.aggstate;
@@ -2120,11 +2122,22 @@ llvm_compile_expr(ExprState *state)
"aggstate.all_pergroups");
v_setoff = l_int32_const(op->d.agg_init_trans.setoff);
v_transno = l_int32_const(op->d.agg_init_trans.transno);
- v_pergroupp =
- LLVMBuildGEP(b,
- l_load_gep1(b, v_allpergroupsp, v_setoff, ""),
- &v_transno, 1, "");
+ v_pergroup_allaggs = l_load_gep1(b, v_allpergroupsp, v_setoff, "");
+ b_check_notransvalue = l_bb_before_v(
+ opblocks[i + 1], "op.%d.check_notransvalue", i);
+
+ LLVMBuildCondBr(b,
+ LLVMBuildICmp(b, LLVMIntEQ,
+ LLVMBuildPtrToInt(b, v_pergroup_allaggs,
+ TypeSizeT, ""),
+ l_sizet_const(0), ""),
+ opblocks[i + 1],
+ b_check_notransvalue);
+
+ LLVMPositionBuilderAtEnd(b, b_check_notransvalue);
+
+ v_pergroupp = LLVMBuildGEP(b, v_pergroup_allaggs, &v_transno, 1, "");
v_notransvalue =
l_load_struct_gep(b, v_pergroupp,
FIELDNO_AGGSTATEPERGROUPDATA_NOTRANSVALUE,
@@ -2191,6 +2204,9 @@ llvm_compile_expr(ExprState *state)
LLVMValueRef v_transnull;
LLVMValueRef v_pergroupp;
+ LLVMValueRef v_pergroup_allaggs;
+
+ LLVMBasicBlockRef b_check_transnull;
int jumpnull = op->d.agg_strict_trans_check.jumpnull;
@@ -2210,11 +2226,22 @@ llvm_compile_expr(ExprState *state)
l_int32_const(op->d.agg_strict_trans_check.setoff);
v_transno =
l_int32_const(op->d.agg_strict_trans_check.transno);
- v_pergroupp =
- LLVMBuildGEP(b,
- l_load_gep1(b, v_allpergroupsp, v_setoff, ""),
- &v_transno, 1, "");
+ v_pergroup_allaggs = l_load_gep1(b, v_allpergroupsp, v_setoff, "");
+
+ b_check_transnull = l_bb_before_v(opblocks[i + 1],
+ "op.%d.check_transnull", i);
+ LLVMBuildCondBr(b,
+ LLVMBuildICmp(b, LLVMIntEQ,
+ LLVMBuildPtrToInt(b, v_pergroup_allaggs,
+ TypeSizeT, ""),
+ l_sizet_const(0), ""),
+ opblocks[jumpnull],
+ b_check_transnull);
+
+ LLVMPositionBuilderAtEnd(b, b_check_transnull);
+
+ v_pergroupp = LLVMBuildGEP(b, v_pergroup_allaggs, &v_transno, 1, "");
v_transnull =
l_load_struct_gep(b, v_pergroupp,
FIELDNO_AGGSTATEPERGROUPDATA_TRANSVALUEISNULL,
@@ -2256,12 +2283,15 @@ llvm_compile_expr(ExprState *state)
LLVMValueRef v_pertransp;
LLVMValueRef v_pergroupp;
+ LLVMValueRef v_pergroup_allaggs;
LLVMValueRef v_retval;
LLVMValueRef v_tmpcontext;
LLVMValueRef v_oldcontext;
+ LLVMBasicBlockRef b_advance_transval;
+
aggstate = op->d.agg_trans.aggstate;
pertrans = op->d.agg_trans.pertrans;
@@ -2283,10 +2313,22 @@ llvm_compile_expr(ExprState *state)
"aggstate.all_pergroups");
v_setoff = l_int32_const(op->d.agg_trans.setoff);
v_transno = l_int32_const(op->d.agg_trans.transno);
- v_pergroupp =
- LLVMBuildGEP(b,
- l_load_gep1(b, v_allpergroupsp, v_setoff, ""),
- &v_transno, 1, "");
+ v_pergroup_allaggs = l_load_gep1(b, v_allpergroupsp, v_setoff, "");
+
+ b_advance_transval = l_bb_before_v(opblocks[i + 1],
+ "op.%d.advance_transval", i);
+
+ LLVMBuildCondBr(b,
+ LLVMBuildICmp(b, LLVMIntEQ,
+ LLVMBuildPtrToInt(b, v_pergroup_allaggs,
+ TypeSizeT, ""),
+ l_sizet_const(0), ""),
+ opblocks[i + 1],
+ b_advance_transval);
+
+ LLVMPositionBuilderAtEnd(b, b_advance_transval);
+
+ v_pergroupp = LLVMBuildGEP(b, v_pergroup_allaggs, &v_transno, 1, "");
v_fcinfo = l_ptr_const(fcinfo,
l_ptr(StructFunctionCallInfoData));
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index c5f65934859..3f0d2899635 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -128,6 +128,7 @@ bool enable_bitmapscan = true;
bool enable_tidscan = true;
bool enable_sort = true;
bool enable_hashagg = true;
+bool enable_hashagg_spill = true;
bool enable_nestloop = true;
bool enable_material = true;
bool enable_mergejoin = true;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 7fe11b59a02..511f8861a8f 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -4255,6 +4255,9 @@ consider_groupingsets_paths(PlannerInfo *root,
* gd->rollups is empty if we have only unsortable columns to work
* with. Override work_mem in that case; otherwise, we'll rely on the
* sorted-input case to generate usable mixed paths.
+ *
+ * TODO: think more about how to plan grouping sets when spilling hash
+ * tables is an option
*/
if (hashsize > work_mem * 1024L && gd->rollups)
return; /* nope, won't fit */
@@ -6527,7 +6530,8 @@ add_paths_to_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
* were unable to sort above, then we'd better generate a Path, so
* that we at least have one.
*/
- if (hashaggtablesize < work_mem * 1024L ||
+ if (enable_hashagg_spill ||
+ hashaggtablesize < work_mem * 1024L ||
grouped_rel->pathlist == NIL)
{
/*
@@ -6560,7 +6564,8 @@ add_paths_to_grouping_rel(PlannerInfo *root, RelOptInfo *input_rel,
agg_final_costs,
dNumGroups);
- if (hashaggtablesize < work_mem * 1024L)
+ if (enable_hashagg_spill ||
+ hashaggtablesize < work_mem * 1024L)
add_path(grouped_rel, (Path *)
create_agg_path(root,
grouped_rel,
@@ -6829,7 +6834,7 @@ create_partial_grouping_paths(PlannerInfo *root,
* Tentatively produce a partial HashAgg Path, depending on if it
* looks as if the hash table will fit in work_mem.
*/
- if (hashaggtablesize < work_mem * 1024L &&
+ if ((enable_hashagg_spill || hashaggtablesize < work_mem * 1024L) &&
cheapest_total_path != NULL)
{
add_path(partially_grouped_rel, (Path *)
@@ -6856,7 +6861,7 @@ create_partial_grouping_paths(PlannerInfo *root,
dNumPartialPartialGroups);
/* Do the same for partial paths. */
- if (hashaggtablesize < work_mem * 1024L &&
+ if ((enable_hashagg_spill || hashaggtablesize < work_mem * 1024L) &&
cheapest_partial_path != NULL)
{
add_partial_path(partially_grouped_rel, (Path *)
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 3bf96de256d..b0cb1d7e6b2 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -120,6 +120,7 @@ bool enableFsync = true;
bool allowSystemTableMods = false;
int work_mem = 1024;
int maintenance_work_mem = 16384;
+bool hashagg_mem_overflow = false;
int max_parallel_maintenance_workers = 2;
/*
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ba4edde71a3..d588198df55 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -957,6 +957,26 @@ static struct config_bool ConfigureNamesBool[] =
true,
NULL, NULL, NULL
},
+ {
+ {"enable_hashagg_spill", PGC_USERSET, QUERY_TUNING_METHOD,
+ gettext_noop("Enables the planner's use of hashed aggregation plans that are expected to exceed work_mem."),
+ NULL,
+ GUC_EXPLAIN
+ },
+ &enable_hashagg_spill,
+ true,
+ NULL, NULL, NULL
+ },
+ {
+ {"hashagg_mem_overflow", PGC_USERSET, QUERY_TUNING_METHOD,
+ gettext_noop("Enables hashed aggregation to overflow work_mem at execution time."),
+ NULL,
+ GUC_EXPLAIN
+ },
+ &hashagg_mem_overflow,
+ false,
+ NULL, NULL, NULL
+ },
{
{"enable_material", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of materialization."),
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index 6298c7c8cad..84a71444264 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -140,10 +140,15 @@ extern TupleHashTable BuildTupleHashTableExt(PlanState *parent,
extern TupleHashEntry LookupTupleHashEntry(TupleHashTable hashtable,
TupleTableSlot *slot,
bool *isnew);
+extern TupleHashEntry LookupTupleHashEntryHash(TupleHashTable hashtable,
+ TupleTableSlot *slot,
+ bool *isnew, uint32 hash);
extern TupleHashEntry FindTupleHashEntry(TupleHashTable hashtable,
TupleTableSlot *slot,
ExprState *eqcomp,
FmgrInfo *hashfunctions);
+extern uint32 TupleHashTableHash(struct tuplehash_hash *tb,
+ const MinimalTuple tuple);
extern void ResetTupleHashTable(TupleHashTable hashtable);
/*
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index bc6e03fbc7e..321759ead51 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -244,6 +244,7 @@ extern bool enableFsync;
extern PGDLLIMPORT bool allowSystemTableMods;
extern PGDLLIMPORT int work_mem;
extern PGDLLIMPORT int maintenance_work_mem;
+extern PGDLLIMPORT bool hashagg_mem_overflow;
extern PGDLLIMPORT int max_parallel_maintenance_workers;
extern int VacuumCostPageHit;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 6eb647290be..e7b12ed39b8 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -2070,13 +2070,26 @@ typedef struct AggState
HeapTuple grp_firstTuple; /* copy of first tuple of current group */
/* these fields are used in AGG_HASHED and AGG_MIXED modes: */
bool table_filled; /* hash table filled yet? */
- int num_hashes;
+ int num_hashes; /* number of hash tables active at once */
+ bool hash_spilled; /* any hash table ever spilled? */
+ struct HashAggSpill *hash_spills; /* HashAggSpill for each hash table,
+ exists only during first pass if spilled */
+ TupleTableSlot *hash_spill_slot; /* slot for reading from spill files */
+ Size hash_mem_limit; /* limit before spilling hash table */
+ Size hash_mem_peak; /* peak hash table memory usage */
+ uint64 hash_ngroups_current; /* number of tuples currently in
+ memory in all hash tables */
+ Size hash_mem_current; /* current hash table memory usage */
+ uint64 hash_disk_used; /* bytes of disk space used */
+ int hash_batches_used; /* batches used during entire execution */
+ List *hash_batches; /* hash batches remaining to be processed */
+
AggStatePerHash perhash; /* array of per-hashtable data */
AggStatePerGroup *hash_pergroup; /* grouping set indexed array of
* per-group pointers */
/* support for evaluation of agg input expressions: */
-#define FIELDNO_AGGSTATE_ALL_PERGROUPS 34
+#define FIELDNO_AGGSTATE_ALL_PERGROUPS 44
AggStatePerGroup *all_pergroups; /* array of first ->pergroups, than
* ->hash_pergroup */
ProjectionInfo *combinedproj; /* projection machinery */
@@ -2248,7 +2261,7 @@ typedef struct HashInstrumentation
int nbuckets_original; /* planned number of buckets */
int nbatch; /* number of batches at end of execution */
int nbatch_original; /* planned number of batches */
- size_t space_peak; /* speak memory usage in bytes */
+ size_t space_peak; /* peak memory usage in bytes */
} HashInstrumentation;
/* ----------------
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index b3d0b4f6fbc..b72e2d08290 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -54,6 +54,7 @@ extern PGDLLIMPORT bool enable_bitmapscan;
extern PGDLLIMPORT bool enable_tidscan;
extern PGDLLIMPORT bool enable_sort;
extern PGDLLIMPORT bool enable_hashagg;
+extern PGDLLIMPORT bool enable_hashagg_spill;
extern PGDLLIMPORT bool enable_nestloop;
extern PGDLLIMPORT bool enable_material;
extern PGDLLIMPORT bool enable_mergejoin;
diff --git a/src/test/regress/expected/aggregates.out b/src/test/regress/expected/aggregates.out
index be4ddf86a43..8b64d15368e 100644
--- a/src/test/regress/expected/aggregates.out
+++ b/src/test/regress/expected/aggregates.out
@@ -2331,3 +2331,95 @@ explain (costs off)
-> Seq Scan on onek
(8 rows)
+--
+-- Compare results between plans using sorting and plans using hash
+-- aggregation. Force spilling in both cases by setting work_mem low.
+--
+set work_mem='64kB';
+-- Produce results with sorting.
+set enable_hashagg = false;
+set jit_above_cost = 0;
+explain (costs off)
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+ QUERY PLAN
+------------------------------------------------
+ GroupAggregate
+ Group Key: ((g % 100000))
+ -> Sort
+ Sort Key: ((g % 100000))
+ -> Function Scan on generate_series g
+(5 rows)
+
+create table agg_group_1 as
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+set jit_above_cost to default;
+create table agg_group_2 as
+select (g/2)::numeric as c1, sum(7::int4) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+create table agg_group_3 as
+select (g/2)::numeric as c1, array_agg(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+-- Produce results with hash aggregation
+set enable_hashagg = true;
+set enable_sort = false;
+set jit_above_cost = 0;
+explain (costs off)
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+ QUERY PLAN
+------------------------------------------
+ HashAggregate
+ Group Key: (g % 100000)
+ -> Function Scan on generate_series g
+(3 rows)
+
+create table agg_hash_1 as
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+set jit_above_cost to default;
+create table agg_hash_2 as
+select (g/2)::numeric as c1, sum(7::int4) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+create table agg_hash_3 as
+select (g/2)::numeric as c1, array_agg(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+set enable_sort = true;
+set work_mem to default;
+-- Compare group aggregation results to hash aggregation results
+(select * from agg_hash_1 except select * from agg_group_1)
+ union all
+(select * from agg_group_1 except select * from agg_hash_1);
+ c1 | c2 | c3
+----+----+----
+(0 rows)
+
+(select * from agg_hash_2 except select * from agg_group_2)
+ union all
+(select * from agg_group_2 except select * from agg_hash_2);
+ c1 | c2 | c3
+----+----+----
+(0 rows)
+
+(select * from agg_hash_3 except select * from agg_group_3)
+ union all
+(select * from agg_group_3 except select * from agg_hash_3);
+ c1 | c2 | c3
+----+----+----
+(0 rows)
+
+drop table agg_group_1;
+drop table agg_group_2;
+drop table agg_group_3;
+drop table agg_hash_1;
+drop table agg_hash_2;
+drop table agg_hash_3;
diff --git a/src/test/regress/expected/groupingsets.out b/src/test/regress/expected/groupingsets.out
index c1f802c88a7..767f60a96c7 100644
--- a/src/test/regress/expected/groupingsets.out
+++ b/src/test/regress/expected/groupingsets.out
@@ -1633,4 +1633,127 @@ select v||'a', case when grouping(v||'a') = 1 then 1 else 0 end, count(*)
| 1 | 2
(4 rows)
+--
+-- Compare results between plans using sorting and plans using hash
+-- aggregation. Force spilling in both cases by setting work_mem low.
+--
+SET work_mem='64kB';
+-- Produce results with sorting.
+set enable_hashagg = false;
+set jit_above_cost = 0;
+explain (costs off)
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+ QUERY PLAN
+---------------------------------------------------------------
+ GroupAggregate
+ Group Key: ((g.g % 1000)), ((g.g % 100)), ((g.g % 10))
+ Group Key: ((g.g % 1000)), ((g.g % 100))
+ Group Key: ((g.g % 1000))
+ Group Key: ()
+ Sort Key: ((g.g % 100)), ((g.g % 10))
+ Group Key: ((g.g % 100)), ((g.g % 10))
+ Group Key: ((g.g % 100))
+ Sort Key: ((g.g % 10)), ((g.g % 1000))
+ Group Key: ((g.g % 10)), ((g.g % 1000))
+ Group Key: ((g.g % 10))
+ -> Sort
+ Sort Key: ((g.g % 1000)), ((g.g % 100)), ((g.g % 10))
+ -> Function Scan on generate_series g
+(14 rows)
+
+create table gs_group_1 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+set jit_above_cost to default;
+create table gs_group_2 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g/20 as g1000, g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by cube (g1000,g100,g10);
+create table gs_group_3 as
+select g100, g10, array_agg(g) as a, count(*) as c, max(g::text) as m from
+ (select g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by grouping sets (g100,g10);
+-- Produce results with hash aggregation.
+set enable_hashagg = true;
+set enable_sort = false;
+set work_mem='64kB';
+set jit_above_cost = 0;
+explain (costs off)
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+ QUERY PLAN
+---------------------------------------------------------------
+ GroupAggregate
+ Group Key: ((g.g % 1000)), ((g.g % 100)), ((g.g % 10))
+ Group Key: ((g.g % 1000)), ((g.g % 100))
+ Group Key: ((g.g % 1000))
+ Group Key: ()
+ Sort Key: ((g.g % 100)), ((g.g % 10))
+ Group Key: ((g.g % 100)), ((g.g % 10))
+ Group Key: ((g.g % 100))
+ Sort Key: ((g.g % 10)), ((g.g % 1000))
+ Group Key: ((g.g % 10)), ((g.g % 1000))
+ Group Key: ((g.g % 10))
+ -> Sort
+ Sort Key: ((g.g % 1000)), ((g.g % 100)), ((g.g % 10))
+ -> Function Scan on generate_series g
+(14 rows)
+
+create table gs_hash_1 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+set jit_above_cost to default;
+create table gs_hash_2 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g/20 as g1000, g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by cube (g1000,g100,g10);
+create table gs_hash_3 as
+select g100, g10, array_agg(g) as a, count(*) as c, max(g::text) as m from
+ (select g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by grouping sets (g100,g10);
+set enable_sort = true;
+set work_mem to default;
+-- Compare results
+(select * from gs_hash_1 except select * from gs_group_1)
+ union all
+(select * from gs_group_1 except select * from gs_hash_1);
+ g1000 | g100 | g10 | sum | count | max
+-------+------+-----+-----+-------+-----
+(0 rows)
+
+(select * from gs_hash_2 except select * from gs_group_2)
+ union all
+(select * from gs_group_2 except select * from gs_hash_2);
+ g1000 | g100 | g10 | sum | count | max
+-------+------+-----+-----+-------+-----
+(0 rows)
+
+(select g100,g10,unnest(a),c,m from gs_hash_3 except
+ select g100,g10,unnest(a),c,m from gs_group_3)
+ union all
+(select g100,g10,unnest(a),c,m from gs_group_3 except
+ select g100,g10,unnest(a),c,m from gs_hash_3);
+ g100 | g10 | unnest | c | m
+------+-----+--------+---+---
+(0 rows)
+
+drop table gs_group_1;
+drop table gs_group_2;
+drop table gs_group_3;
+drop table gs_hash_1;
+drop table gs_hash_2;
+drop table gs_hash_3;
-- end
diff --git a/src/test/regress/expected/select_distinct.out b/src/test/regress/expected/select_distinct.out
index f3696c6d1de..11c6f50fbfa 100644
--- a/src/test/regress/expected/select_distinct.out
+++ b/src/test/regress/expected/select_distinct.out
@@ -148,6 +148,68 @@ SELECT count(*) FROM
4
(1 row)
+--
+-- Compare results between plans using sorting and plans using hash
+-- aggregation. Force spilling in both cases by setting work_mem low.
+--
+SET work_mem='64kB';
+-- Produce results with sorting.
+SET enable_hashagg=FALSE;
+SET jit_above_cost=0;
+EXPLAIN (costs off)
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+ QUERY PLAN
+------------------------------------------------
+ Unique
+ -> Sort
+ Sort Key: ((g % 1000))
+ -> Function Scan on generate_series g
+(4 rows)
+
+CREATE TABLE distinct_group_1 AS
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+SET jit_above_cost TO DEFAULT;
+CREATE TABLE distinct_group_2 AS
+SELECT DISTINCT (g%1000)::text FROM generate_series(0,9999) g;
+SET enable_hashagg=TRUE;
+-- Produce results with hash aggregation.
+SET enable_sort=FALSE;
+SET jit_above_cost=0;
+EXPLAIN (costs off)
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+ QUERY PLAN
+------------------------------------------
+ HashAggregate
+ Group Key: (g % 1000)
+ -> Function Scan on generate_series g
+(3 rows)
+
+CREATE TABLE distinct_hash_1 AS
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+SET jit_above_cost TO DEFAULT;
+CREATE TABLE distinct_hash_2 AS
+SELECT DISTINCT (g%1000)::text FROM generate_series(0,9999) g;
+SET enable_sort=TRUE;
+SET work_mem TO DEFAULT;
+-- Compare results
+(SELECT * FROM distinct_hash_1 EXCEPT SELECT * FROM distinct_group_1)
+ UNION ALL
+(SELECT * FROM distinct_group_1 EXCEPT SELECT * FROM distinct_hash_1);
+ ?column?
+----------
+(0 rows)
+
+(SELECT * FROM distinct_hash_1 EXCEPT SELECT * FROM distinct_group_1)
+ UNION ALL
+(SELECT * FROM distinct_group_1 EXCEPT SELECT * FROM distinct_hash_1);
+ ?column?
+----------
+(0 rows)
+
+DROP TABLE distinct_hash_1;
+DROP TABLE distinct_hash_2;
+DROP TABLE distinct_group_1;
+DROP TABLE distinct_group_2;
--
-- Also, some tests of IS DISTINCT FROM, which doesn't quite deserve its
-- very own regression file.
diff --git a/src/test/regress/expected/sysviews.out b/src/test/regress/expected/sysviews.out
index a1c90eb9057..c40bf6c16eb 100644
--- a/src/test/regress/expected/sysviews.out
+++ b/src/test/regress/expected/sysviews.out
@@ -75,6 +75,7 @@ select name, setting from pg_settings where name like 'enable%';
enable_bitmapscan | on
enable_gathermerge | on
enable_hashagg | on
+ enable_hashagg_spill | on
enable_hashjoin | on
enable_indexonlyscan | on
enable_indexscan | on
@@ -89,7 +90,7 @@ select name, setting from pg_settings where name like 'enable%';
enable_seqscan | on
enable_sort | on
enable_tidscan | on
-(17 rows)
+(18 rows)
-- Test that the pg_timezone_names and pg_timezone_abbrevs views are
-- more-or-less working. We can't test their contents in any great detail
diff --git a/src/test/regress/sql/aggregates.sql b/src/test/regress/sql/aggregates.sql
index 17fb256aec5..bcd336c5812 100644
--- a/src/test/regress/sql/aggregates.sql
+++ b/src/test/regress/sql/aggregates.sql
@@ -1017,3 +1017,91 @@ select v||'a', case when v||'a' = 'aa' then 1 else 0 end, count(*)
explain (costs off)
select 1 from tenk1
where (hundred, thousand) in (select twothousand, twothousand from onek);
+
+--
+-- Compare results between plans using sorting and plans using hash
+-- aggregation. Force spilling in both cases by setting work_mem low.
+--
+
+set work_mem='64kB';
+
+-- Produce results with sorting.
+
+set enable_hashagg = false;
+
+set jit_above_cost = 0;
+
+explain (costs off)
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+
+create table agg_group_1 as
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+
+set jit_above_cost to default;
+
+create table agg_group_2 as
+select (g/2)::numeric as c1, sum(7::int4) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+
+create table agg_group_3 as
+select (g/2)::numeric as c1, array_agg(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+
+-- Produce results with hash aggregation
+
+set enable_hashagg = true;
+set enable_sort = false;
+
+set jit_above_cost = 0;
+
+explain (costs off)
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+
+create table agg_hash_1 as
+select g%100000 as c1, sum(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 199999) g
+ group by g%100000;
+
+set jit_above_cost to default;
+
+create table agg_hash_2 as
+select (g/2)::numeric as c1, sum(7::int4) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+
+create table agg_hash_3 as
+select (g/2)::numeric as c1, array_agg(g::numeric) as c2, count(*) as c3
+ from generate_series(0, 1999) g
+ group by g/2;
+
+set enable_sort = true;
+set work_mem to default;
+
+-- Compare group aggregation results to hash aggregation results
+
+(select * from agg_hash_1 except select * from agg_group_1)
+ union all
+(select * from agg_group_1 except select * from agg_hash_1);
+
+(select * from agg_hash_2 except select * from agg_group_2)
+ union all
+(select * from agg_group_2 except select * from agg_hash_2);
+
+(select * from agg_hash_3 except select * from agg_group_3)
+ union all
+(select * from agg_group_3 except select * from agg_hash_3);
+
+drop table agg_group_1;
+drop table agg_group_2;
+drop table agg_group_3;
+drop table agg_hash_1;
+drop table agg_hash_2;
+drop table agg_hash_3;
diff --git a/src/test/regress/sql/groupingsets.sql b/src/test/regress/sql/groupingsets.sql
index 95ac3fb52f6..bf8bce6ed31 100644
--- a/src/test/regress/sql/groupingsets.sql
+++ b/src/test/regress/sql/groupingsets.sql
@@ -441,4 +441,103 @@ select v||'a', case when grouping(v||'a') = 1 then 1 else 0 end, count(*)
from unnest(array[1,1], array['a','b']) u(i,v)
group by rollup(i, v||'a') order by 1,3;
+--
+-- Compare results between plans using sorting and plans using hash
+-- aggregation. Force spilling in both cases by setting work_mem low.
+--
+
+SET work_mem='64kB';
+
+-- Produce results with sorting.
+
+set enable_hashagg = false;
+
+set jit_above_cost = 0;
+
+explain (costs off)
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+
+create table gs_group_1 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+
+set jit_above_cost to default;
+
+create table gs_group_2 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g/20 as g1000, g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by cube (g1000,g100,g10);
+
+create table gs_group_3 as
+select g100, g10, array_agg(g) as a, count(*) as c, max(g::text) as m from
+ (select g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by grouping sets (g100,g10);
+
+-- Produce results with hash aggregation.
+
+set enable_hashagg = true;
+set enable_sort = false;
+set work_mem='64kB';
+
+set jit_above_cost = 0;
+
+explain (costs off)
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+
+create table gs_hash_1 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g%1000 as g1000, g%100 as g100, g%10 as g10, g
+ from generate_series(0,199999) g) s
+group by cube (g1000,g100,g10);
+
+set jit_above_cost to default;
+
+create table gs_hash_2 as
+select g1000, g100, g10, sum(g::numeric), count(*), max(g::text) from
+ (select g/20 as g1000, g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by cube (g1000,g100,g10);
+
+create table gs_hash_3 as
+select g100, g10, array_agg(g) as a, count(*) as c, max(g::text) as m from
+ (select g/200 as g100, g/2000 as g10, g
+ from generate_series(0,19999) g) s
+group by grouping sets (g100,g10);
+
+set enable_sort = true;
+set work_mem to default;
+
+-- Compare results
+
+(select * from gs_hash_1 except select * from gs_group_1)
+ union all
+(select * from gs_group_1 except select * from gs_hash_1);
+
+(select * from gs_hash_2 except select * from gs_group_2)
+ union all
+(select * from gs_group_2 except select * from gs_hash_2);
+
+(select g100,g10,unnest(a),c,m from gs_hash_3 except
+ select g100,g10,unnest(a),c,m from gs_group_3)
+ union all
+(select g100,g10,unnest(a),c,m from gs_group_3 except
+ select g100,g10,unnest(a),c,m from gs_hash_3);
+
+drop table gs_group_1;
+drop table gs_group_2;
+drop table gs_group_3;
+drop table gs_hash_1;
+drop table gs_hash_2;
+drop table gs_hash_3;
+
-- end
diff --git a/src/test/regress/sql/select_distinct.sql b/src/test/regress/sql/select_distinct.sql
index a605e86449e..33102744ebf 100644
--- a/src/test/regress/sql/select_distinct.sql
+++ b/src/test/regress/sql/select_distinct.sql
@@ -45,6 +45,68 @@ SELECT count(*) FROM
SELECT count(*) FROM
(SELECT DISTINCT two, four, two FROM tenk1) ss;
+--
+-- Compare results between plans using sorting and plans using hash
+-- aggregation. Force spilling in both cases by setting work_mem low.
+--
+
+SET work_mem='64kB';
+
+-- Produce results with sorting.
+
+SET enable_hashagg=FALSE;
+
+SET jit_above_cost=0;
+
+EXPLAIN (costs off)
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+CREATE TABLE distinct_group_1 AS
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+SET jit_above_cost TO DEFAULT;
+
+CREATE TABLE distinct_group_2 AS
+SELECT DISTINCT (g%1000)::text FROM generate_series(0,9999) g;
+
+SET enable_hashagg=TRUE;
+
+-- Produce results with hash aggregation.
+
+SET enable_sort=FALSE;
+
+SET jit_above_cost=0;
+
+EXPLAIN (costs off)
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+CREATE TABLE distinct_hash_1 AS
+SELECT DISTINCT g%1000 FROM generate_series(0,9999) g;
+
+SET jit_above_cost TO DEFAULT;
+
+CREATE TABLE distinct_hash_2 AS
+SELECT DISTINCT (g%1000)::text FROM generate_series(0,9999) g;
+
+SET enable_sort=TRUE;
+
+SET work_mem TO DEFAULT;
+
+-- Compare results
+
+(SELECT * FROM distinct_hash_1 EXCEPT SELECT * FROM distinct_group_1)
+ UNION ALL
+(SELECT * FROM distinct_group_1 EXCEPT SELECT * FROM distinct_hash_1);
+
+(SELECT * FROM distinct_hash_1 EXCEPT SELECT * FROM distinct_group_1)
+ UNION ALL
+(SELECT * FROM distinct_group_1 EXCEPT SELECT * FROM distinct_hash_1);
+
+DROP TABLE distinct_hash_1;
+DROP TABLE distinct_hash_2;
+DROP TABLE distinct_group_1;
+DROP TABLE distinct_group_2;
+
--
-- Also, some tests of IS DISTINCT FROM, which doesn't quite deserve its
-- very own regression file.