PostgreSQL Source Code  git master
tableam.c File Reference
#include "postgres.h"
#include <math.h>
#include "access/syncscan.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "optimizer/plancat.h"
#include "port/pg_bitutils.h"
#include "storage/bufmgr.h"
#include "storage/shmem.h"
#include "storage/smgr.h"
Include dependency graph for tableam.c:

Go to the source code of this file.

Macros

#define PARALLEL_SEQSCAN_NCHUNKS   2048
 
#define PARALLEL_SEQSCAN_RAMPDOWN_CHUNKS   64
 
#define PARALLEL_SEQSCAN_MAX_CHUNK_SIZE   8192
 

Functions

const TupleTableSlotOpstable_slot_callbacks (Relation relation)
 
TupleTableSlottable_slot_create (Relation relation, List **reglist)
 
TableScanDesc table_beginscan_catalog (Relation relation, int nkeys, struct ScanKeyData *key)
 
Size table_parallelscan_estimate (Relation rel, Snapshot snapshot)
 
void table_parallelscan_initialize (Relation rel, ParallelTableScanDesc pscan, Snapshot snapshot)
 
TableScanDesc table_beginscan_parallel (Relation relation, ParallelTableScanDesc pscan)
 
bool table_index_fetch_tuple_check (Relation rel, ItemPointer tid, Snapshot snapshot, bool *all_dead)
 
void table_tuple_get_latest_tid (TableScanDesc scan, ItemPointer tid)
 
void simple_table_tuple_insert (Relation rel, TupleTableSlot *slot)
 
void simple_table_tuple_delete (Relation rel, ItemPointer tid, Snapshot snapshot)
 
void simple_table_tuple_update (Relation rel, ItemPointer otid, TupleTableSlot *slot, Snapshot snapshot, TU_UpdateIndexes *update_indexes)
 
Size table_block_parallelscan_estimate (Relation rel)
 
Size table_block_parallelscan_initialize (Relation rel, ParallelTableScanDesc pscan)
 
void table_block_parallelscan_reinitialize (Relation rel, ParallelTableScanDesc pscan)
 
void table_block_parallelscan_startblock_init (Relation rel, ParallelBlockTableScanWorker pbscanwork, ParallelBlockTableScanDesc pbscan)
 
BlockNumber table_block_parallelscan_nextpage (Relation rel, ParallelBlockTableScanWorker pbscanwork, ParallelBlockTableScanDesc pbscan)
 
uint64 table_block_relation_size (Relation rel, ForkNumber forkNumber)
 
void table_block_relation_estimate_size (Relation rel, int32 *attr_widths, BlockNumber *pages, double *tuples, double *allvisfrac, Size overhead_bytes_per_tuple, Size usable_bytes_per_page)
 

Variables

char * default_table_access_method = DEFAULT_TABLE_ACCESS_METHOD
 
bool synchronize_seqscans = true
 

Macro Definition Documentation

◆ PARALLEL_SEQSCAN_MAX_CHUNK_SIZE

#define PARALLEL_SEQSCAN_MAX_CHUNK_SIZE   8192

Definition at line 45 of file tableam.c.

◆ PARALLEL_SEQSCAN_NCHUNKS

#define PARALLEL_SEQSCAN_NCHUNKS   2048

Definition at line 41 of file tableam.c.

◆ PARALLEL_SEQSCAN_RAMPDOWN_CHUNKS

#define PARALLEL_SEQSCAN_RAMPDOWN_CHUNKS   64

Definition at line 43 of file tableam.c.

Function Documentation

◆ simple_table_tuple_delete()

void simple_table_tuple_delete ( Relation  rel,
ItemPointer  tid,
Snapshot  snapshot 
)

Definition at line 290 of file tableam.c.

291 {
292  TM_Result result;
293  TM_FailureData tmfd;
294 
295  result = table_tuple_delete(rel, tid,
296  GetCurrentCommandId(true),
297  snapshot, InvalidSnapshot,
298  true /* wait for commit */ ,
299  &tmfd, false /* changingPart */ );
300 
301  switch (result)
302  {
303  case TM_SelfModified:
304  /* Tuple was already updated in current command? */
305  elog(ERROR, "tuple already updated by self");
306  break;
307 
308  case TM_Ok:
309  /* done successfully */
310  break;
311 
312  case TM_Updated:
313  elog(ERROR, "tuple concurrently updated");
314  break;
315 
316  case TM_Deleted:
317  elog(ERROR, "tuple concurrently deleted");
318  break;
319 
320  default:
321  elog(ERROR, "unrecognized table_tuple_delete status: %u", result);
322  break;
323  }
324 }
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:224
#define InvalidSnapshot
Definition: snapshot.h:123
TM_Result
Definition: tableam.h:80
@ TM_Ok
Definition: tableam.h:85
@ TM_Deleted
Definition: tableam.h:100
@ TM_Updated
Definition: tableam.h:97
@ TM_SelfModified
Definition: tableam.h:91
static TM_Result table_tuple_delete(Relation rel, ItemPointer tid, CommandId cid, Snapshot snapshot, Snapshot crosscheck, bool wait, TM_FailureData *tmfd, bool changingPart)
Definition: tableam.h:1501
CommandId GetCurrentCommandId(bool used)
Definition: xact.c:826

References elog, ERROR, GetCurrentCommandId(), InvalidSnapshot, table_tuple_delete(), TM_Deleted, TM_Ok, TM_SelfModified, and TM_Updated.

Referenced by ExecSimpleRelationDelete().

◆ simple_table_tuple_insert()

void simple_table_tuple_insert ( Relation  rel,
TupleTableSlot slot 
)

Definition at line 276 of file tableam.c.

277 {
278  table_tuple_insert(rel, slot, GetCurrentCommandId(true), 0, NULL);
279 }
static void table_tuple_insert(Relation rel, TupleTableSlot *slot, CommandId cid, int options, struct BulkInsertStateData *bistate)
Definition: tableam.h:1412

References GetCurrentCommandId(), and table_tuple_insert().

Referenced by ExecSimpleRelationInsert().

◆ simple_table_tuple_update()

void simple_table_tuple_update ( Relation  rel,
ItemPointer  otid,
TupleTableSlot slot,
Snapshot  snapshot,
TU_UpdateIndexes update_indexes 
)

Definition at line 335 of file tableam.c.

339 {
340  TM_Result result;
341  TM_FailureData tmfd;
342  LockTupleMode lockmode;
343 
344  result = table_tuple_update(rel, otid, slot,
345  GetCurrentCommandId(true),
346  snapshot, InvalidSnapshot,
347  true /* wait for commit */ ,
348  &tmfd, &lockmode, update_indexes);
349 
350  switch (result)
351  {
352  case TM_SelfModified:
353  /* Tuple was already updated in current command? */
354  elog(ERROR, "tuple already updated by self");
355  break;
356 
357  case TM_Ok:
358  /* done successfully */
359  break;
360 
361  case TM_Updated:
362  elog(ERROR, "tuple concurrently updated");
363  break;
364 
365  case TM_Deleted:
366  elog(ERROR, "tuple concurrently deleted");
367  break;
368 
369  default:
370  elog(ERROR, "unrecognized table_tuple_update status: %u", result);
371  break;
372  }
373 }
LockTupleMode
Definition: lockoptions.h:50
static TM_Result table_tuple_update(Relation rel, ItemPointer otid, TupleTableSlot *slot, CommandId cid, Snapshot snapshot, Snapshot crosscheck, bool wait, TM_FailureData *tmfd, LockTupleMode *lockmode, TU_UpdateIndexes *update_indexes)
Definition: tableam.h:1545

References elog, ERROR, GetCurrentCommandId(), InvalidSnapshot, table_tuple_update(), TM_Deleted, TM_Ok, TM_SelfModified, and TM_Updated.

Referenced by ExecSimpleRelationUpdate().

◆ table_beginscan_catalog()

TableScanDesc table_beginscan_catalog ( Relation  relation,
int  nkeys,
struct ScanKeyData key 
)

Definition at line 112 of file tableam.c.

113 {
114  uint32 flags = SO_TYPE_SEQSCAN |
116  Oid relid = RelationGetRelid(relation);
117  Snapshot snapshot = RegisterSnapshot(GetCatalogSnapshot(relid));
118 
119  return relation->rd_tableam->scan_begin(relation, snapshot, nkeys, key,
120  NULL, flags);
121 }
unsigned int uint32
Definition: c.h:506
unsigned int Oid
Definition: postgres_ext.h:31
#define RelationGetRelid(relation)
Definition: rel.h:505
Snapshot GetCatalogSnapshot(Oid relid)
Definition: snapmgr.c:352
Snapshot RegisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:794
const struct TableAmRoutine * rd_tableam
Definition: rel.h:189
TableScanDesc(* scan_begin)(Relation rel, Snapshot snapshot, int nkeys, struct ScanKeyData *key, ParallelTableScanDesc pscan, uint32 flags)
Definition: tableam.h:328
@ SO_ALLOW_STRAT
Definition: tableam.h:58
@ SO_TEMP_SNAPSHOT
Definition: tableam.h:65
@ SO_ALLOW_PAGEMODE
Definition: tableam.h:62
@ SO_ALLOW_SYNC
Definition: tableam.h:60
@ SO_TYPE_SEQSCAN
Definition: tableam.h:49

References GetCatalogSnapshot(), sort-test::key, RelationData::rd_tableam, RegisterSnapshot(), RelationGetRelid, TableAmRoutine::scan_begin, SO_ALLOW_PAGEMODE, SO_ALLOW_STRAT, SO_ALLOW_SYNC, SO_TEMP_SNAPSHOT, and SO_TYPE_SEQSCAN.

Referenced by AlterTableMoveAll(), AlterTableSpaceOptions(), check_db_file_conflict(), CreateDatabaseUsingFileCopy(), do_autovacuum(), DropSetting(), DropTableSpace(), find_typed_table_dependencies(), get_all_vacuum_rels(), get_database_list(), get_subscription_list(), get_tables_to_cluster(), get_tablespace_name(), get_tablespace_oid(), GetAllTablesPublicationRelations(), getRelationsInNamespace(), GetSchemaPublicationRelations(), index_update_stats(), objectsInSchemaToOids(), populate_typ_list(), ReindexMultipleTables(), remove_dbtablespaces(), RemoveSubscriptionRel(), RenameTableSpace(), ThereIsAtLeastOneRole(), and vac_truncate_clog().

◆ table_beginscan_parallel()

TableScanDesc table_beginscan_parallel ( Relation  relation,
ParallelTableScanDesc  pscan 
)

Definition at line 165 of file tableam.c.

166 {
167  Snapshot snapshot;
168  uint32 flags = SO_TYPE_SEQSCAN |
170 
171  Assert(RelationGetRelid(relation) == pscan->phs_relid);
172 
173  if (!pscan->phs_snapshot_any)
174  {
175  /* Snapshot was serialized -- restore it */
176  snapshot = RestoreSnapshot((char *) pscan + pscan->phs_snapshot_off);
177  RegisterSnapshot(snapshot);
178  flags |= SO_TEMP_SNAPSHOT;
179  }
180  else
181  {
182  /* SnapshotAny passed by caller (not serialized) */
183  snapshot = SnapshotAny;
184  }
185 
186  return relation->rd_tableam->scan_begin(relation, snapshot, 0, NULL,
187  pscan, flags);
188 }
#define Assert(condition)
Definition: c.h:858
Snapshot RestoreSnapshot(char *start_address)
Definition: snapmgr.c:1775
#define SnapshotAny
Definition: snapmgr.h:33

References Assert, ParallelTableScanDescData::phs_relid, ParallelTableScanDescData::phs_snapshot_any, ParallelTableScanDescData::phs_snapshot_off, RelationData::rd_tableam, RegisterSnapshot(), RelationGetRelid, RestoreSnapshot(), TableAmRoutine::scan_begin, SnapshotAny, SO_ALLOW_PAGEMODE, SO_ALLOW_STRAT, SO_ALLOW_SYNC, SO_TEMP_SNAPSHOT, and SO_TYPE_SEQSCAN.

Referenced by _brin_parallel_scan_and_build(), _bt_parallel_scan_and_sort(), ExecSeqScanInitializeDSM(), and ExecSeqScanInitializeWorker().

◆ table_block_parallelscan_estimate()

Size table_block_parallelscan_estimate ( Relation  rel)

Definition at line 382 of file tableam.c.

383 {
384  return sizeof(ParallelBlockTableScanDescData);
385 }
struct ParallelBlockTableScanDescData ParallelBlockTableScanDescData

◆ table_block_parallelscan_initialize()

Size table_block_parallelscan_initialize ( Relation  rel,
ParallelTableScanDesc  pscan 
)

Definition at line 388 of file tableam.c.

389 {
391 
392  bpscan->base.phs_relid = RelationGetRelid(rel);
393  bpscan->phs_nblocks = RelationGetNumberOfBlocks(rel);
394  /* compare phs_syncscan initialization to similar logic in initscan */
396  !RelationUsesLocalBuffers(rel) &&
397  bpscan->phs_nblocks > NBuffers / 4;
398  SpinLockInit(&bpscan->phs_mutex);
400  pg_atomic_init_u64(&bpscan->phs_nallocated, 0);
401 
402  return sizeof(ParallelBlockTableScanDescData);
403 }
static void pg_atomic_init_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:448
#define InvalidBlockNumber
Definition: block.h:33
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:277
int NBuffers
Definition: globals.c:139
#define RelationUsesLocalBuffers(relation)
Definition: rel.h:637
struct ParallelBlockTableScanDescData * ParallelBlockTableScanDesc
Definition: relscan.h:85
#define SpinLockInit(lock)
Definition: spin.h:60
pg_atomic_uint64 phs_nallocated
Definition: relscan.h:82
ParallelTableScanDescData base
Definition: relscan.h:77
bool synchronize_seqscans
Definition: tableam.c:49

References ParallelBlockTableScanDescData::base, InvalidBlockNumber, NBuffers, pg_atomic_init_u64(), ParallelBlockTableScanDescData::phs_mutex, ParallelBlockTableScanDescData::phs_nallocated, ParallelBlockTableScanDescData::phs_nblocks, ParallelTableScanDescData::phs_relid, ParallelBlockTableScanDescData::phs_startblock, ParallelTableScanDescData::phs_syncscan, RelationGetNumberOfBlocks, RelationGetRelid, RelationUsesLocalBuffers, SpinLockInit, and synchronize_seqscans.

◆ table_block_parallelscan_nextpage()

BlockNumber table_block_parallelscan_nextpage ( Relation  rel,
ParallelBlockTableScanWorker  pbscanwork,
ParallelBlockTableScanDesc  pbscan 
)

Definition at line 491 of file tableam.c.

494 {
495  BlockNumber page;
496  uint64 nallocated;
497 
498  /*
499  * The logic below allocates block numbers out to parallel workers in a
500  * way that each worker will receive a set of consecutive block numbers to
501  * scan. Earlier versions of this would allocate the next highest block
502  * number to the next worker to call this function. This would generally
503  * result in workers never receiving consecutive block numbers. Some
504  * operating systems would not detect the sequential I/O pattern due to
505  * each backend being a different process which could result in poor
506  * performance due to inefficient or no readahead. To work around this
507  * issue, we now allocate a range of block numbers for each worker and
508  * when they come back for another block, we give them the next one in
509  * that range until the range is complete. When the worker completes the
510  * range of blocks we then allocate another range for it and return the
511  * first block number from that range.
512  *
513  * Here we name these ranges of blocks "chunks". The initial size of
514  * these chunks is determined in table_block_parallelscan_startblock_init
515  * based on the size of the relation. Towards the end of the scan, we
516  * start making reductions in the size of the chunks in order to attempt
517  * to divide the remaining work over all the workers as evenly as
518  * possible.
519  *
520  * Here pbscanwork is local worker memory. phsw_chunk_remaining tracks
521  * the number of blocks remaining in the chunk. When that reaches 0 then
522  * we must allocate a new chunk for the worker.
523  *
524  * phs_nallocated tracks how many blocks have been allocated to workers
525  * already. When phs_nallocated >= rs_nblocks, all blocks have been
526  * allocated.
527  *
528  * Because we use an atomic fetch-and-add to fetch the current value, the
529  * phs_nallocated counter will exceed rs_nblocks, because workers will
530  * still increment the value, when they try to allocate the next block but
531  * all blocks have been allocated already. The counter must be 64 bits
532  * wide because of that, to avoid wrapping around when rs_nblocks is close
533  * to 2^32.
534  *
535  * The actual block to return is calculated by adding the counter to the
536  * starting block number, modulo nblocks.
537  */
538 
539  /*
540  * First check if we have any remaining blocks in a previous chunk for
541  * this worker. We must consume all of the blocks from that before we
542  * allocate a new chunk to the worker.
543  */
544  if (pbscanwork->phsw_chunk_remaining > 0)
545  {
546  /*
547  * Give them the next block in the range and update the remaining
548  * number of blocks.
549  */
550  nallocated = ++pbscanwork->phsw_nallocated;
551  pbscanwork->phsw_chunk_remaining--;
552  }
553  else
554  {
555  /*
556  * When we've only got PARALLEL_SEQSCAN_RAMPDOWN_CHUNKS chunks
557  * remaining in the scan, we half the chunk size. Since we reduce the
558  * chunk size here, we'll hit this again after doing
559  * PARALLEL_SEQSCAN_RAMPDOWN_CHUNKS at the new size. After a few
560  * iterations of this, we'll end up doing the last few blocks with the
561  * chunk size set to 1.
562  */
563  if (pbscanwork->phsw_chunk_size > 1 &&
564  pbscanwork->phsw_nallocated > pbscan->phs_nblocks -
566  pbscanwork->phsw_chunk_size >>= 1;
567 
568  nallocated = pbscanwork->phsw_nallocated =
570  pbscanwork->phsw_chunk_size);
571 
572  /*
573  * Set the remaining number of blocks in this chunk so that subsequent
574  * calls from this worker continue on with this chunk until it's done.
575  */
576  pbscanwork->phsw_chunk_remaining = pbscanwork->phsw_chunk_size - 1;
577  }
578 
579  if (nallocated >= pbscan->phs_nblocks)
580  page = InvalidBlockNumber; /* all blocks have been allocated */
581  else
582  page = (nallocated + pbscan->phs_startblock) % pbscan->phs_nblocks;
583 
584  /*
585  * Report scan location. Normally, we report the current page number.
586  * When we reach the end of the scan, though, we report the starting page,
587  * not the ending page, just so the starting positions for later scans
588  * doesn't slew backwards. We only report the position at the end of the
589  * scan once, though: subsequent callers will report nothing.
590  */
591  if (pbscan->base.phs_syncscan)
592  {
593  if (page != InvalidBlockNumber)
594  ss_report_location(rel, page);
595  else if (nallocated == pbscan->phs_nblocks)
596  ss_report_location(rel, pbscan->phs_startblock);
597  }
598 
599  return page;
600 }
static uint64 pg_atomic_fetch_add_u64(volatile pg_atomic_uint64 *ptr, int64 add_)
Definition: atomics.h:518
uint32 BlockNumber
Definition: block.h:31
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77
void ss_report_location(Relation rel, BlockNumber location)
Definition: syncscan.c:289
#define PARALLEL_SEQSCAN_RAMPDOWN_CHUNKS
Definition: tableam.c:43

References ParallelBlockTableScanDescData::base, if(), InvalidBlockNumber, PARALLEL_SEQSCAN_RAMPDOWN_CHUNKS, pg_atomic_fetch_add_u64(), ParallelBlockTableScanDescData::phs_nallocated, ParallelBlockTableScanDescData::phs_nblocks, ParallelBlockTableScanDescData::phs_startblock, ParallelTableScanDescData::phs_syncscan, ParallelBlockTableScanWorkerData::phsw_chunk_remaining, ParallelBlockTableScanWorkerData::phsw_chunk_size, ParallelBlockTableScanWorkerData::phsw_nallocated, and ss_report_location().

Referenced by heap_scan_stream_read_next_parallel().

◆ table_block_parallelscan_reinitialize()

void table_block_parallelscan_reinitialize ( Relation  rel,
ParallelTableScanDesc  pscan 
)

Definition at line 406 of file tableam.c.

407 {
409 
410  pg_atomic_write_u64(&bpscan->phs_nallocated, 0);
411 }
static void pg_atomic_write_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:480

References pg_atomic_write_u64(), and ParallelBlockTableScanDescData::phs_nallocated.

◆ table_block_parallelscan_startblock_init()

void table_block_parallelscan_startblock_init ( Relation  rel,
ParallelBlockTableScanWorker  pbscanwork,
ParallelBlockTableScanDesc  pbscan 
)

Definition at line 421 of file tableam.c.

424 {
425  BlockNumber sync_startpage = InvalidBlockNumber;
426 
427  /* Reset the state we use for controlling allocation size. */
428  memset(pbscanwork, 0, sizeof(*pbscanwork));
429 
430  StaticAssertStmt(MaxBlockNumber <= 0xFFFFFFFE,
431  "pg_nextpower2_32 may be too small for non-standard BlockNumber width");
432 
433  /*
434  * We determine the chunk size based on the size of the relation. First we
435  * split the relation into PARALLEL_SEQSCAN_NCHUNKS chunks but we then
436  * take the next highest power of 2 number of the chunk size. This means
437  * we split the relation into somewhere between PARALLEL_SEQSCAN_NCHUNKS
438  * and PARALLEL_SEQSCAN_NCHUNKS / 2 chunks.
439  */
440  pbscanwork->phsw_chunk_size = pg_nextpower2_32(Max(pbscan->phs_nblocks /
442 
443  /*
444  * Ensure we don't go over the maximum chunk size with larger tables. This
445  * means we may get much more than PARALLEL_SEQSCAN_NCHUNKS for larger
446  * tables. Too large a chunk size has been shown to be detrimental to
447  * synchronous scan performance.
448  */
449  pbscanwork->phsw_chunk_size = Min(pbscanwork->phsw_chunk_size,
451 
452 retry:
453  /* Grab the spinlock. */
454  SpinLockAcquire(&pbscan->phs_mutex);
455 
456  /*
457  * If the scan's startblock has not yet been initialized, we must do so
458  * now. If this is not a synchronized scan, we just start at block 0, but
459  * if it is a synchronized scan, we must get the starting position from
460  * the synchronized scan machinery. We can't hold the spinlock while
461  * doing that, though, so release the spinlock, get the information we
462  * need, and retry. If nobody else has initialized the scan in the
463  * meantime, we'll fill in the value we fetched on the second time
464  * through.
465  */
466  if (pbscan->phs_startblock == InvalidBlockNumber)
467  {
468  if (!pbscan->base.phs_syncscan)
469  pbscan->phs_startblock = 0;
470  else if (sync_startpage != InvalidBlockNumber)
471  pbscan->phs_startblock = sync_startpage;
472  else
473  {
474  SpinLockRelease(&pbscan->phs_mutex);
475  sync_startpage = ss_get_location(rel, pbscan->phs_nblocks);
476  goto retry;
477  }
478  }
479  SpinLockRelease(&pbscan->phs_mutex);
480 }
#define MaxBlockNumber
Definition: block.h:35
#define Min(x, y)
Definition: c.h:1004
#define Max(x, y)
Definition: c.h:998
#define StaticAssertStmt(condition, errmessage)
Definition: c.h:938
static uint32 pg_nextpower2_32(uint32 num)
Definition: pg_bitutils.h:189
#define SpinLockRelease(lock)
Definition: spin.h:64
#define SpinLockAcquire(lock)
Definition: spin.h:62
BlockNumber ss_get_location(Relation rel, BlockNumber relnblocks)
Definition: syncscan.c:254
#define PARALLEL_SEQSCAN_MAX_CHUNK_SIZE
Definition: tableam.c:45
#define PARALLEL_SEQSCAN_NCHUNKS
Definition: tableam.c:41

References ParallelBlockTableScanDescData::base, InvalidBlockNumber, Max, MaxBlockNumber, Min, PARALLEL_SEQSCAN_MAX_CHUNK_SIZE, PARALLEL_SEQSCAN_NCHUNKS, pg_nextpower2_32(), ParallelBlockTableScanDescData::phs_mutex, ParallelBlockTableScanDescData::phs_nblocks, ParallelBlockTableScanDescData::phs_startblock, ParallelTableScanDescData::phs_syncscan, ParallelBlockTableScanWorkerData::phsw_chunk_size, SpinLockAcquire, SpinLockRelease, ss_get_location(), and StaticAssertStmt.

Referenced by heap_scan_stream_read_next_parallel().

◆ table_block_relation_estimate_size()

void table_block_relation_estimate_size ( Relation  rel,
int32 attr_widths,
BlockNumber pages,
double *  tuples,
double *  allvisfrac,
Size  overhead_bytes_per_tuple,
Size  usable_bytes_per_page 
)

Definition at line 653 of file tableam.c.

658 {
659  BlockNumber curpages;
660  BlockNumber relpages;
661  double reltuples;
662  BlockNumber relallvisible;
663  double density;
664 
665  /* it should have storage, so we can call the smgr */
666  curpages = RelationGetNumberOfBlocks(rel);
667 
668  /* coerce values in pg_class to more desirable types */
669  relpages = (BlockNumber) rel->rd_rel->relpages;
670  reltuples = (double) rel->rd_rel->reltuples;
671  relallvisible = (BlockNumber) rel->rd_rel->relallvisible;
672 
673  /*
674  * HACK: if the relation has never yet been vacuumed, use a minimum size
675  * estimate of 10 pages. The idea here is to avoid assuming a
676  * newly-created table is really small, even if it currently is, because
677  * that may not be true once some data gets loaded into it. Once a vacuum
678  * or analyze cycle has been done on it, it's more reasonable to believe
679  * the size is somewhat stable.
680  *
681  * (Note that this is only an issue if the plan gets cached and used again
682  * after the table has been filled. What we're trying to avoid is using a
683  * nestloop-type plan on a table that has grown substantially since the
684  * plan was made. Normally, autovacuum/autoanalyze will occur once enough
685  * inserts have happened and cause cached-plan invalidation; but that
686  * doesn't happen instantaneously, and it won't happen at all for cases
687  * such as temporary tables.)
688  *
689  * We test "never vacuumed" by seeing whether reltuples < 0.
690  *
691  * If the table has inheritance children, we don't apply this heuristic.
692  * Totally empty parent tables are quite common, so we should be willing
693  * to believe that they are empty.
694  */
695  if (curpages < 10 &&
696  reltuples < 0 &&
697  !rel->rd_rel->relhassubclass)
698  curpages = 10;
699 
700  /* report estimated # pages */
701  *pages = curpages;
702  /* quick exit if rel is clearly empty */
703  if (curpages == 0)
704  {
705  *tuples = 0;
706  *allvisfrac = 0;
707  return;
708  }
709 
710  /* estimate number of tuples from previous tuple density */
711  if (reltuples >= 0 && relpages > 0)
712  density = reltuples / (double) relpages;
713  else
714  {
715  /*
716  * When we have no data because the relation was never yet vacuumed,
717  * estimate tuple width from attribute datatypes. We assume here that
718  * the pages are completely full, which is OK for tables but is
719  * probably an overestimate for indexes. Fortunately
720  * get_relation_info() can clamp the overestimate to the parent
721  * table's size.
722  *
723  * Note: this code intentionally disregards alignment considerations,
724  * because (a) that would be gilding the lily considering how crude
725  * the estimate is, (b) it creates platform dependencies in the
726  * default plans which are kind of a headache for regression testing,
727  * and (c) different table AMs might use different padding schemes.
728  */
729  int32 tuple_width;
730  int fillfactor;
731 
732  /*
733  * Without reltuples/relpages, we also need to consider fillfactor.
734  * The other branch considers it implicitly by calculating density
735  * from actual relpages/reltuples statistics.
736  */
738 
739  tuple_width = get_rel_data_width(rel, attr_widths);
740  tuple_width += overhead_bytes_per_tuple;
741  /* note: integer division is intentional here */
742  density = (usable_bytes_per_page * fillfactor / 100) / tuple_width;
743  }
744  *tuples = rint(density * (double) curpages);
745 
746  /*
747  * We use relallvisible as-is, rather than scaling it up like we do for
748  * the pages and tuples counts, on the theory that any pages added since
749  * the last VACUUM are most likely not marked all-visible. But costsize.c
750  * wants it converted to a fraction.
751  */
752  if (relallvisible == 0 || curpages <= 0)
753  *allvisfrac = 0;
754  else if ((double) relallvisible >= curpages)
755  *allvisfrac = 1;
756  else
757  *allvisfrac = (double) relallvisible / curpages;
758 }
signed int int32
Definition: c.h:494
int fillfactor
Definition: pgbench.c:187
int32 get_rel_data_width(Relation rel, int32 *attr_widths)
Definition: plancat.c:1173
#define RelationGetFillFactor(relation, defaultff)
Definition: rel.h:363
#define HEAP_DEFAULT_FILLFACTOR
Definition: rel.h:349
Form_pg_class rd_rel
Definition: rel.h:111

References fillfactor, get_rel_data_width(), HEAP_DEFAULT_FILLFACTOR, if(), RelationData::rd_rel, RelationGetFillFactor, and RelationGetNumberOfBlocks.

Referenced by heapam_estimate_rel_size().

◆ table_block_relation_size()

uint64 table_block_relation_size ( Relation  rel,
ForkNumber  forkNumber 
)

Definition at line 616 of file tableam.c.

617 {
618  uint64 nblocks = 0;
619 
620  /* InvalidForkNumber indicates returning the size for all forks */
621  if (forkNumber == InvalidForkNumber)
622  {
623  for (int i = 0; i < MAX_FORKNUM; i++)
624  nblocks += smgrnblocks(RelationGetSmgr(rel), i);
625  }
626  else
627  nblocks = smgrnblocks(RelationGetSmgr(rel), forkNumber);
628 
629  return nblocks * BLCKSZ;
630 }
int i
Definition: isn.c:73
static SMgrRelation RelationGetSmgr(Relation rel)
Definition: rel.h:567
@ InvalidForkNumber
Definition: relpath.h:49
#define MAX_FORKNUM
Definition: relpath.h:62
BlockNumber smgrnblocks(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:655

References i, InvalidForkNumber, MAX_FORKNUM, RelationGetSmgr(), and smgrnblocks().

◆ table_index_fetch_tuple_check()

bool table_index_fetch_tuple_check ( Relation  rel,
ItemPointer  tid,
Snapshot  snapshot,
bool all_dead 
)

Definition at line 208 of file tableam.c.

212 {
213  IndexFetchTableData *scan;
214  TupleTableSlot *slot;
215  bool call_again = false;
216  bool found;
217 
218  slot = table_slot_create(rel, NULL);
219  scan = table_index_fetch_begin(rel);
220  found = table_index_fetch_tuple(scan, tid, snapshot, slot, &call_again,
221  all_dead);
222  table_index_fetch_end(scan);
224 
225  return found;
226 }
void ExecDropSingleTupleTableSlot(TupleTableSlot *slot)
Definition: execTuples.c:1341
TupleTableSlot * table_slot_create(Relation relation, List **reglist)
Definition: tableam.c:91
static IndexFetchTableData * table_index_fetch_begin(Relation rel)
Definition: tableam.h:1202
static void table_index_fetch_end(struct IndexFetchTableData *scan)
Definition: tableam.h:1221
static bool table_index_fetch_tuple(struct IndexFetchTableData *scan, ItemPointer tid, Snapshot snapshot, TupleTableSlot *slot, bool *call_again, bool *all_dead)
Definition: tableam.h:1251

References ExecDropSingleTupleTableSlot(), table_index_fetch_begin(), table_index_fetch_end(), table_index_fetch_tuple(), and table_slot_create().

Referenced by _bt_check_unique().

◆ table_parallelscan_estimate()

Size table_parallelscan_estimate ( Relation  rel,
Snapshot  snapshot 
)

Definition at line 130 of file tableam.c.

131 {
132  Size sz = 0;
133 
134  if (IsMVCCSnapshot(snapshot))
135  sz = add_size(sz, EstimateSnapshotSpace(snapshot));
136  else
137  Assert(snapshot == SnapshotAny);
138 
139  sz = add_size(sz, rel->rd_tableam->parallelscan_estimate(rel));
140 
141  return sz;
142 }
size_t Size
Definition: c.h:605
Size add_size(Size s1, Size s2)
Definition: shmem.c:493
Size EstimateSnapshotSpace(Snapshot snapshot)
Definition: snapmgr.c:1692
#define IsMVCCSnapshot(snapshot)
Definition: snapmgr.h:62
Size(* parallelscan_estimate)(Relation rel)
Definition: tableam.h:393

References add_size(), Assert, EstimateSnapshotSpace(), IsMVCCSnapshot, TableAmRoutine::parallelscan_estimate, RelationData::rd_tableam, and SnapshotAny.

Referenced by _brin_parallel_estimate_shared(), _bt_parallel_estimate_shared(), and ExecSeqScanEstimate().

◆ table_parallelscan_initialize()

void table_parallelscan_initialize ( Relation  rel,
ParallelTableScanDesc  pscan,
Snapshot  snapshot 
)

Definition at line 145 of file tableam.c.

147 {
148  Size snapshot_off = rel->rd_tableam->parallelscan_initialize(rel, pscan);
149 
150  pscan->phs_snapshot_off = snapshot_off;
151 
152  if (IsMVCCSnapshot(snapshot))
153  {
154  SerializeSnapshot(snapshot, (char *) pscan + pscan->phs_snapshot_off);
155  pscan->phs_snapshot_any = false;
156  }
157  else
158  {
159  Assert(snapshot == SnapshotAny);
160  pscan->phs_snapshot_any = true;
161  }
162 }
void SerializeSnapshot(Snapshot snapshot, char *start_address)
Definition: snapmgr.c:1716
Size(* parallelscan_initialize)(Relation rel, ParallelTableScanDesc pscan)
Definition: tableam.h:400

References Assert, IsMVCCSnapshot, TableAmRoutine::parallelscan_initialize, ParallelTableScanDescData::phs_snapshot_any, ParallelTableScanDescData::phs_snapshot_off, RelationData::rd_tableam, SerializeSnapshot(), and SnapshotAny.

Referenced by _brin_begin_parallel(), _bt_begin_parallel(), and ExecSeqScanInitializeDSM().

◆ table_slot_callbacks()

const TupleTableSlotOps* table_slot_callbacks ( Relation  relation)

Definition at line 58 of file tableam.c.

59 {
60  const TupleTableSlotOps *tts_cb;
61 
62  if (relation->rd_tableam)
63  tts_cb = relation->rd_tableam->slot_callbacks(relation);
64  else if (relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
65  {
66  /*
67  * Historically FDWs expect to store heap tuples in slots. Continue
68  * handing them one, to make it less painful to adapt FDWs to new
69  * versions. The cost of a heap slot over a virtual slot is pretty
70  * small.
71  */
72  tts_cb = &TTSOpsHeapTuple;
73  }
74  else
75  {
76  /*
77  * These need to be supported, as some parts of the code (like COPY)
78  * need to create slots for such relations too. It seems better to
79  * centralize the knowledge that a heap slot is the right thing in
80  * that case here.
81  */
82  Assert(relation->rd_rel->relkind == RELKIND_VIEW ||
83  relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
84  tts_cb = &TTSOpsVirtual;
85  }
86 
87  return tts_cb;
88 }
const TupleTableSlotOps TTSOpsVirtual
Definition: execTuples.c:84
const TupleTableSlotOps TTSOpsHeapTuple
Definition: execTuples.c:85
const TupleTableSlotOps *(* slot_callbacks)(Relation rel)
Definition: tableam.h:304

References Assert, RelationData::rd_rel, RelationData::rd_tableam, TableAmRoutine::slot_callbacks, TTSOpsHeapTuple, and TTSOpsVirtual.

Referenced by ATRewriteTable(), createSplitPartitionContext(), ExecGetReturningSlot(), ExecGetTriggerNewSlot(), ExecGetTriggerOldSlot(), ExecInitBitmapHeapScan(), ExecInitIndexOnlyScan(), ExecInitIndexScan(), ExecInitSampleScan(), ExecInitSeqScan(), ExecInitTidRangeScan(), ExecInitTidScan(), moveMergedTablesRows(), moveSplitTableRows(), and table_slot_create().

◆ table_slot_create()

TupleTableSlot* table_slot_create ( Relation  relation,
List **  reglist 
)

Definition at line 91 of file tableam.c.

92 {
93  const TupleTableSlotOps *tts_cb;
94  TupleTableSlot *slot;
95 
96  tts_cb = table_slot_callbacks(relation);
97  slot = MakeSingleTupleTableSlot(RelationGetDescr(relation), tts_cb);
98 
99  if (reglist)
100  *reglist = lappend(*reglist, slot);
101 
102  return slot;
103 }
TupleTableSlot * MakeSingleTupleTableSlot(TupleDesc tupdesc, const TupleTableSlotOps *tts_ops)
Definition: execTuples.c:1325
List * lappend(List *list, void *datum)
Definition: list.c:339
#define RelationGetDescr(relation)
Definition: rel.h:531
const TupleTableSlotOps * table_slot_callbacks(Relation relation)
Definition: tableam.c:58

References lappend(), MakeSingleTupleTableSlot(), RelationGetDescr, and table_slot_callbacks().

Referenced by acquire_sample_rows(), apply_handle_tuple_routing(), check_default_partition_contents(), check_exclusion_or_unique_constraint(), CopyFrom(), CopyMultiInsertInfoNextFreeSlot(), DoCopyTo(), EvalPlanQualSlot(), ExecCrossPartitionUpdate(), ExecInitInsertProjection(), ExecInitMerge(), ExecInitMergeTupleSlots(), ExecInitModifyTable(), ExecInitPartitionInfo(), ExecInitRoutingInfo(), ExecInitUpdateProjection(), FindReplTupleInLocalRel(), get_actual_variable_range(), heap_entry_is_visible(), heapam_index_build_range_scan(), heapam_relation_copy_for_cluster(), IndexCheckExclusion(), RelationFindReplTupleSeq(), systable_beginscan(), systable_beginscan_ordered(), table_index_fetch_tuple_check(), validateDomainCheckConstraint(), validateDomainNotNullConstraint(), and validateForeignKeyConstraint().

◆ table_tuple_get_latest_tid()

void table_tuple_get_latest_tid ( TableScanDesc  scan,
ItemPointer  tid 
)

Definition at line 235 of file tableam.c.

236 {
237  Relation rel = scan->rs_rd;
238  const TableAmRoutine *tableam = rel->rd_tableam;
239 
240  /*
241  * We don't expect direct calls to table_tuple_get_latest_tid with valid
242  * CheckXidAlive for catalog or regular tables. See detailed comments in
243  * xact.c where these variables are declared.
244  */
246  elog(ERROR, "unexpected table_tuple_get_latest_tid call during logical decoding");
247 
248  /*
249  * Since this can be called with user-supplied TID, don't trust the input
250  * too much.
251  */
252  if (!tableam->tuple_tid_valid(scan, tid))
253  ereport(ERROR,
254  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
255  errmsg("tid (%u, %u) is not valid for relation \"%s\"",
258  RelationGetRelationName(rel))));
259 
260  tableam->tuple_get_latest_tid(scan, tid);
261 }
#define unlikely(x)
Definition: c.h:311
int errcode(int sqlerrcode)
Definition: elog.c:857
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define ereport(elevel,...)
Definition: elog.h:149
static OffsetNumber ItemPointerGetOffsetNumberNoCheck(const ItemPointerData *pointer)
Definition: itemptr.h:114
static BlockNumber ItemPointerGetBlockNumberNoCheck(const ItemPointerData *pointer)
Definition: itemptr.h:93
#define RelationGetRelationName(relation)
Definition: rel.h:539
void(* tuple_get_latest_tid)(TableScanDesc scan, ItemPointer tid)
Definition: tableam.h:489
bool(* tuple_tid_valid)(TableScanDesc scan, ItemPointer tid)
Definition: tableam.h:482
Relation rs_rd
Definition: relscan.h:34
#define TransactionIdIsValid(xid)
Definition: transam.h:41
bool bsysscan
Definition: xact.c:98
TransactionId CheckXidAlive
Definition: xact.c:97

References bsysscan, CheckXidAlive, elog, ereport, errcode(), errmsg(), ERROR, ItemPointerGetBlockNumberNoCheck(), ItemPointerGetOffsetNumberNoCheck(), RelationData::rd_tableam, RelationGetRelationName, TableScanDescData::rs_rd, TransactionIdIsValid, TableAmRoutine::tuple_get_latest_tid, TableAmRoutine::tuple_tid_valid, and unlikely.

Referenced by currtid_internal(), and TidNext().

Variable Documentation

◆ default_table_access_method

char* default_table_access_method = DEFAULT_TABLE_ACCESS_METHOD

Definition at line 48 of file tableam.c.

Referenced by ATPrepSetAccessMethod(), and DefineRelation().

◆ synchronize_seqscans

bool synchronize_seqscans = true

Definition at line 49 of file tableam.c.

Referenced by initscan(), and table_block_parallelscan_initialize().