PostgreSQL Source Code  git master
hashsort.c File Reference
#include "postgres.h"
#include "access/hash.h"
#include "commands/progress.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "port/pg_bitutils.h"
#include "utils/tuplesort.h"
Include dependency graph for hashsort.c:

Go to the source code of this file.

Data Structures

struct  HSpool
 

Functions

HSpool_h_spoolinit (Relation heap, Relation index, uint32 num_buckets)
 
void _h_spooldestroy (HSpool *hspool)
 
void _h_spool (HSpool *hspool, ItemPointer self, Datum *values, bool *isnull)
 
void _h_indexbuild (HSpool *hspool, Relation heapRel)
 

Function Documentation

◆ _h_indexbuild()

void _h_indexbuild ( HSpool hspool,
Relation  heapRel 
)

Definition at line 119 of file hashsort.c.

References _hash_doinsert(), _hash_get_indextuple_hashkey(), _hash_hashkey2bucket(), Assert, HSpool::high_mask, HSpool::index, HSpool::low_mask, HSpool::max_buckets, pgstat_progress_update_param(), PROGRESS_CREATEIDX_TUPLES_DONE, HSpool::sortstate, tuplesort_getindextuple(), and tuplesort_performsort().

Referenced by hashbuild().

120 {
121  IndexTuple itup;
122  int64 tups_done = 0;
123 #ifdef USE_ASSERT_CHECKING
124  uint32 hashkey = 0;
125 #endif
126 
128 
129  while ((itup = tuplesort_getindextuple(hspool->sortstate, true)) != NULL)
130  {
131  /*
132  * Technically, it isn't critical that hash keys be found in sorted
133  * order, since this sorting is only used to increase locality of
134  * access as a performance optimization. It still seems like a good
135  * idea to test tuplesort.c's handling of hash index tuple sorts
136  * through an assertion, though.
137  */
138 #ifdef USE_ASSERT_CHECKING
139  uint32 lasthashkey = hashkey;
140 
142  hspool->max_buckets, hspool->high_mask,
143  hspool->low_mask);
144  Assert(hashkey >= lasthashkey);
145 #endif
146 
147  _hash_doinsert(hspool->index, itup, heapRel);
148 
150  ++tups_done);
151  }
152 }
IndexTuple tuplesort_getindextuple(Tuplesortstate *state, bool forward)
Definition: tuplesort.c:2446
void _hash_doinsert(Relation rel, IndexTuple itup, Relation heapRel)
Definition: hashinsert.c:36
void tuplesort_performsort(Tuplesortstate *state)
Definition: tuplesort.c:2021
Bucket _hash_hashkey2bucket(uint32 hashkey, uint32 maxbucket, uint32 highmask, uint32 lowmask)
Definition: hashutil.c:126
void pgstat_progress_update_param(int index, int64 val)
Definition: pgstat.c:3377
Tuplesortstate * sortstate
Definition: hashsort.c:41
uint32 low_mask
Definition: hashsort.c:50
uint32 high_mask
Definition: hashsort.c:49
uint32 _hash_get_indextuple_hashkey(IndexTuple itup)
Definition: hashutil.c:292
unsigned int uint32
Definition: c.h:429
uint32 max_buckets
Definition: hashsort.c:51
Relation index
Definition: hashsort.c:42
#define Assert(condition)
Definition: c.h:800
#define PROGRESS_CREATEIDX_TUPLES_DONE
Definition: progress.h:85

◆ _h_spool()

void _h_spool ( HSpool hspool,
ItemPointer  self,
Datum values,
bool isnull 
)

Definition at line 108 of file hashsort.c.

References HSpool::index, HSpool::sortstate, and tuplesort_putindextuplevalues().

Referenced by hashbuildCallback().

109 {
111  self, values, isnull);
112 }
Tuplesortstate * sortstate
Definition: hashsort.c:41
Relation index
Definition: hashsort.c:42
void tuplesort_putindextuplevalues(Tuplesortstate *state, Relation rel, ItemPointer self, Datum *values, bool *isnull)
Definition: tuplesort.c:1708
static Datum values[MAXATTR]
Definition: bootstrap.c:165

◆ _h_spooldestroy()

void _h_spooldestroy ( HSpool hspool)

Definition at line 98 of file hashsort.c.

References pfree(), HSpool::sortstate, and tuplesort_end().

Referenced by hashbuild().

99 {
100  tuplesort_end(hspool->sortstate);
101  pfree(hspool);
102 }
Tuplesortstate * sortstate
Definition: hashsort.c:41
void pfree(void *pointer)
Definition: mcxt.c:1057
void tuplesort_end(Tuplesortstate *state)
Definition: tuplesort.c:1445

◆ _h_spoolinit()

HSpool* _h_spoolinit ( Relation  heap,
Relation  index,
uint32  num_buckets 
)

Definition at line 59 of file hashsort.c.

References HSpool::high_mask, HSpool::index, HSpool::low_mask, maintenance_work_mem, HSpool::max_buckets, palloc0(), pg_nextpower2_32(), HSpool::sortstate, and tuplesort_begin_index_hash().

Referenced by hashbuild().

60 {
61  HSpool *hspool = (HSpool *) palloc0(sizeof(HSpool));
62 
63  hspool->index = index;
64 
65  /*
66  * Determine the bitmask for hash code values. Since there are currently
67  * num_buckets buckets in the index, the appropriate mask can be computed
68  * as follows.
69  *
70  * NOTE : This hash mask calculation should be in sync with similar
71  * calculation in _hash_init_metabuffer.
72  */
73  hspool->high_mask = pg_nextpower2_32(num_buckets + 1) - 1;
74  hspool->low_mask = (hspool->high_mask >> 1);
75  hspool->max_buckets = num_buckets - 1;
76 
77  /*
78  * We size the sort area as maintenance_work_mem rather than work_mem to
79  * speed index creation. This should be OK since a single backend can't
80  * run multiple index creations in parallel.
81  */
83  index,
84  hspool->high_mask,
85  hspool->low_mask,
86  hspool->max_buckets,
88  NULL,
89  false);
90 
91  return hspool;
92 }
Tuplesortstate * tuplesort_begin_index_hash(Relation heapRel, Relation indexRel, uint32 high_mask, uint32 low_mask, uint32 max_buckets, int workMem, SortCoordinate coordinate, bool randomAccess)
Definition: tuplesort.c:1125
Tuplesortstate * sortstate
Definition: hashsort.c:41
uint32 low_mask
Definition: hashsort.c:50
uint32 high_mask
Definition: hashsort.c:49
static uint32 pg_nextpower2_32(uint32 num)
Definition: pg_bitutils.h:146
void * palloc0(Size size)
Definition: mcxt.c:981
uint32 max_buckets
Definition: hashsort.c:51
Relation index
Definition: hashsort.c:42
int maintenance_work_mem
Definition: globals.c:123