database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-12 21:01:52 +03:00
Code Activity

Injection points for hash aggregation.

Browse Source 
Requires adding a guard against shift-by-32. Previously, that was
impossible because the number of partitions was always greater than 1,
but a new injection point can force the number of partitions to 1.

Discussion: https://postgr.es/m/ff4e59305e5d689e03cd256a736348d3e7958f8f.camel@j-davis.com
This commit is contained in:
Jeff Davis
2025-02-11 11:26:25 -08:00
parent 052026c9b9
commit 38172d1856
5 changed files with 141 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
src/backend/executor/nodeAgg.c
View File

@ -269,6 +269,7 @@
#include "utils/datum.h"
#include "utils/dynahash.h"
#include "utils/expandeddatum.h"
#include "utils/injection_point.h"
#include "utils/logtape.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
@ -1489,6 +1490,14 @@ build_hash_tables(AggState *aggstate)
perhash->aggnode->numGroups,
memory);
#ifdef USE_INJECTION_POINTS
if (IS_INJECTION_POINT_ATTACHED("hash-aggregate-oversize-table"))
{
nbuckets = memory / sizeof(TupleHashEntryData);
INJECTION_POINT_CACHED("hash-aggregate-oversize-table");
}
#endif
build_hash_table(aggstate, setno, nbuckets);
}
@ -1860,6 +1869,18 @@ hash_agg_check_limits(AggState *aggstate)
true);
Size hashkey_mem = MemoryContextMemAllocated(aggstate->hashcontext->ecxt_per_tuple_memory,
true);
bool do_spill = false;
#ifdef USE_INJECTION_POINTS
if (ngroups >= 1000)
{
if (IS_INJECTION_POINT_ATTACHED("hash-aggregate-spill-1000"))
{
do_spill = true;
INJECTION_POINT_CACHED("hash-aggregate-spill-1000");
}
}
#endif
/*
* Don't spill unless there's at least one group in the hash table so we
@ -1869,8 +1890,11 @@ hash_agg_check_limits(AggState *aggstate)
(meta_mem + hashkey_mem > aggstate->hash_mem_limit ||
ngroups > aggstate->hash_ngroups_limit))
{
hash_agg_enter_spill_mode(aggstate);
do_spill = true;
}
if (do_spill)
hash_agg_enter_spill_mode(aggstate);
}
/*
@ -1881,6 +1905,7 @@ hash_agg_check_limits(AggState *aggstate)
static void
hash_agg_enter_spill_mode(AggState *aggstate)
{
INJECTION_POINT("hash-aggregate-enter-spill-mode");
aggstate->hash_spill_mode = true;
hashagg_recompile_expressions(aggstate, aggstate->table_filled, true);
@ -2652,6 +2677,7 @@ agg_refill_hash_table(AggState *aggstate)
*/
hashagg_recompile_expressions(aggstate, true, true);
INJECTION_POINT("hash-aggregate-process-batch");
for (;;)
{
TupleTableSlot *spillslot = aggstate->hash_spill_rslot;
@ -2900,6 +2926,15 @@ hashagg_spill_init(HashAggSpill *spill, LogicalTapeSet *tapeset, int used_bits,
npartitions = hash_choose_num_partitions(input_groups, hashentrysize,
used_bits, &partition_bits);
#ifdef USE_INJECTION_POINTS
if (IS_INJECTION_POINT_ATTACHED("hash-aggregate-single-partition"))
{
npartitions = 1;
partition_bits = 0;
INJECTION_POINT_CACHED("hash-aggregate-single-partition");
}
#endif
spill->partitions = palloc0(sizeof(LogicalTape *) * npartitions);
spill->ntuples = palloc0(sizeof(int64) * npartitions);
spill->hll_card = palloc0(sizeof(hyperLogLogState) * npartitions);
@ -2908,7 +2943,10 @@ hashagg_spill_init(HashAggSpill *spill, LogicalTapeSet *tapeset, int used_bits,
spill->partitions[i] = LogicalTapeCreate(tapeset);
spill->shift = 32 - used_bits - partition_bits;
spill->mask = (npartitions - 1) << spill->shift;
if (spill->shift < 32)
spill->mask = (npartitions - 1) << spill->shift;
else
spill->mask = 0;
spill->npartitions = npartitions;
for (int i = 0; i < npartitions; i++)
@ -2957,7 +2995,11 @@ hashagg_spill_tuple(AggState *aggstate, HashAggSpill *spill,
tuple = ExecFetchSlotMinimalTuple(spillslot, &shouldFree);
partition = (hash & spill->mask) >> spill->shift;
if (spill->shift < 32)
partition = (hash & spill->mask) >> spill->shift;
else
partition = 0;
spill->ntuples[partition]++;
/*