PostgreSQL Source Code  git master
rewriteheap.h File Reference
#include "access/htup.h"
#include "storage/itemptr.h"
#include "storage/relfilenode.h"
#include "utils/relcache.h"
Include dependency graph for rewriteheap.h:
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Data Structures

struct  LogicalRewriteMappingData
 

Macros

#define LOGICAL_REWRITE_FORMAT   "map-%x-%x-%X_%X-%x-%x"
 

Typedefs

typedef struct RewriteStateDataRewriteState
 
typedef struct LogicalRewriteMappingData LogicalRewriteMappingData
 

Functions

RewriteState begin_heap_rewrite (Relation OldHeap, Relation NewHeap, TransactionId OldestXmin, TransactionId FreezeXid, MultiXactId MultiXactCutoff, bool use_wal)
 
void end_heap_rewrite (RewriteState state)
 
void rewrite_heap_tuple (RewriteState state, HeapTuple oldTuple, HeapTuple newTuple)
 
bool rewrite_heap_dead_tuple (RewriteState state, HeapTuple oldTuple)
 
void CheckPointLogicalRewriteHeap (void)
 

Macro Definition Documentation

◆ LOGICAL_REWRITE_FORMAT

#define LOGICAL_REWRITE_FORMAT   "map-%x-%x-%X_%X-%x-%x"

Typedef Documentation

◆ LogicalRewriteMappingData

◆ RewriteState

Definition at line 22 of file rewriteheap.h.

Function Documentation

◆ begin_heap_rewrite()

RewriteState begin_heap_rewrite ( Relation  OldHeap,
Relation  NewHeap,
TransactionId  OldestXmin,
TransactionId  FreezeXid,
MultiXactId  MultiXactCutoff,
bool  use_wal 
)

Definition at line 248 of file rewriteheap.c.

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, CurrentMemoryContext, HASHCTL::entrysize, HASH_BLOBS, HASH_CONTEXT, hash_create(), HASH_ELEM, HASHCTL::hcxt, HASHCTL::keysize, logical_begin_heap_rewrite(), MemoryContextSwitchTo(), palloc(), palloc0(), RelationGetNumberOfBlocks, RewriteStateData::rs_blockno, RewriteStateData::rs_buffer, RewriteStateData::rs_buffer_valid, RewriteStateData::rs_cutoff_multi, RewriteStateData::rs_cxt, RewriteStateData::rs_freeze_xid, RewriteStateData::rs_new_rel, RewriteStateData::rs_old_new_tid_map, RewriteStateData::rs_old_rel, RewriteStateData::rs_oldest_xmin, RewriteStateData::rs_unresolved_tups, and RewriteStateData::rs_use_wal.

Referenced by copy_heap_data().

251 {
253  MemoryContext rw_cxt;
254  MemoryContext old_cxt;
255  HASHCTL hash_ctl;
256 
257  /*
258  * To ease cleanup, make a separate context that will contain the
259  * RewriteState struct itself plus all subsidiary data.
260  */
262  "Table rewrite",
264  old_cxt = MemoryContextSwitchTo(rw_cxt);
265 
266  /* Create and fill in the state struct */
267  state = palloc0(sizeof(RewriteStateData));
268 
269  state->rs_old_rel = old_heap;
270  state->rs_new_rel = new_heap;
271  state->rs_buffer = (Page) palloc(BLCKSZ);
272  /* new_heap needn't be empty, just locked */
273  state->rs_blockno = RelationGetNumberOfBlocks(new_heap);
274  state->rs_buffer_valid = false;
275  state->rs_use_wal = use_wal;
276  state->rs_oldest_xmin = oldest_xmin;
277  state->rs_freeze_xid = freeze_xid;
278  state->rs_cutoff_multi = cutoff_multi;
279  state->rs_cxt = rw_cxt;
280 
281  /* Initialize hash tables used to track update chains */
282  memset(&hash_ctl, 0, sizeof(hash_ctl));
283  hash_ctl.keysize = sizeof(TidHashKey);
284  hash_ctl.entrysize = sizeof(UnresolvedTupData);
285  hash_ctl.hcxt = state->rs_cxt;
286 
287  state->rs_unresolved_tups =
288  hash_create("Rewrite / Unresolved ctids",
289  128, /* arbitrary initial size */
290  &hash_ctl,
292 
293  hash_ctl.entrysize = sizeof(OldToNewMappingData);
294 
295  state->rs_old_new_tid_map =
296  hash_create("Rewrite / Old to new tid map",
297  128, /* arbitrary initial size */
298  &hash_ctl,
300 
301  MemoryContextSwitchTo(old_cxt);
302 
304 
305  return state;
306 }
#define HASH_CONTEXT
Definition: hsearch.h:93
#define HASH_ELEM
Definition: hsearch.h:87
MemoryContext hcxt
Definition: hsearch.h:78
TransactionId rs_freeze_xid
Definition: rewriteheap.c:152
MultiXactId rs_cutoff_multi
Definition: rewriteheap.c:156
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
Size entrysize
Definition: hsearch.h:73
Relation rs_new_rel
Definition: rewriteheap.c:144
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:161
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:192
MemoryContext CurrentMemoryContext
Definition: mcxt.c:38
#define AllocSetContextCreate(parent, name, allocparams)
Definition: memutils.h:170
TransactionId rs_oldest_xmin
Definition: rewriteheap.c:150
#define HASH_BLOBS
Definition: hsearch.h:88
MemoryContext rs_cxt
Definition: rewriteheap.c:158
void * palloc0(Size size)
Definition: mcxt.c:955
HTAB * hash_create(const char *tabname, long nelem, HASHCTL *info, int flags)
Definition: dynahash.c:316
Size keysize
Definition: hsearch.h:72
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:199
static void logical_begin_heap_rewrite(RewriteState state)
Definition: rewriteheap.c:803
HTAB * rs_old_new_tid_map
Definition: rewriteheap.c:162
Definition: regguts.h:298
void * palloc(Size size)
Definition: mcxt.c:924
Relation rs_old_rel
Definition: rewriteheap.c:143
BlockNumber rs_blockno
Definition: rewriteheap.c:146
Pointer Page
Definition: bufpage.h:74

◆ CheckPointLogicalRewriteHeap()

void CheckPointLogicalRewriteHeap ( void  )

Definition at line 1202 of file rewriteheap.c.

References AllocateDir(), CloseTransientFile(), dirent::d_name, DEBUG1, elog, ereport, errcode_for_file_access(), errmsg(), ERROR, fd(), FreeDir(), GetRedoRecPtr(), InvalidXLogRecPtr, LOGICAL_REWRITE_FORMAT, lstat, MAXPGPATH, OpenTransientFile(), PG_BINARY, pg_fsync(), pgstat_report_wait_end(), pgstat_report_wait_start(), ReadDir(), ReplicationSlotsComputeLogicalRestartLSN(), S_ISREG, snprintf(), stat, and WAIT_EVENT_LOGICAL_REWRITE_CHECKPOINT_SYNC.

Referenced by CheckPointGuts().

1203 {
1204  XLogRecPtr cutoff;
1205  XLogRecPtr redo;
1206  DIR *mappings_dir;
1207  struct dirent *mapping_de;
1208  char path[MAXPGPATH + 20];
1209 
1210  /*
1211  * We start of with a minimum of the last redo pointer. No new decoding
1212  * slot will start before that, so that's a safe upper bound for removal.
1213  */
1214  redo = GetRedoRecPtr();
1215 
1216  /* now check for the restart ptrs from existing slots */
1218 
1219  /* don't start earlier than the restart lsn */
1220  if (cutoff != InvalidXLogRecPtr && redo < cutoff)
1221  cutoff = redo;
1222 
1223  mappings_dir = AllocateDir("pg_logical/mappings");
1224  while ((mapping_de = ReadDir(mappings_dir, "pg_logical/mappings")) != NULL)
1225  {
1226  struct stat statbuf;
1227  Oid dboid;
1228  Oid relid;
1229  XLogRecPtr lsn;
1230  TransactionId rewrite_xid;
1231  TransactionId create_xid;
1232  uint32 hi,
1233  lo;
1234 
1235  if (strcmp(mapping_de->d_name, ".") == 0 ||
1236  strcmp(mapping_de->d_name, "..") == 0)
1237  continue;
1238 
1239  snprintf(path, sizeof(path), "pg_logical/mappings/%s", mapping_de->d_name);
1240  if (lstat(path, &statbuf) == 0 && !S_ISREG(statbuf.st_mode))
1241  continue;
1242 
1243  /* Skip over files that cannot be ours. */
1244  if (strncmp(mapping_de->d_name, "map-", 4) != 0)
1245  continue;
1246 
1247  if (sscanf(mapping_de->d_name, LOGICAL_REWRITE_FORMAT,
1248  &dboid, &relid, &hi, &lo, &rewrite_xid, &create_xid) != 6)
1249  elog(ERROR, "could not parse filename \"%s\"", mapping_de->d_name);
1250 
1251  lsn = ((uint64) hi) << 32 | lo;
1252 
1253  if (lsn < cutoff || cutoff == InvalidXLogRecPtr)
1254  {
1255  elog(DEBUG1, "removing logical rewrite file \"%s\"", path);
1256  if (unlink(path) < 0)
1257  ereport(ERROR,
1259  errmsg("could not remove file \"%s\": %m", path)));
1260  }
1261  else
1262  {
1263  int fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
1264 
1265  /*
1266  * The file cannot vanish due to concurrency since this function
1267  * is the only one removing logical mappings and it's run while
1268  * CheckpointLock is held exclusively.
1269  */
1270  if (fd < 0)
1271  ereport(ERROR,
1273  errmsg("could not open file \"%s\": %m", path)));
1274 
1275  /*
1276  * We could try to avoid fsyncing files that either haven't
1277  * changed or have only been created since the checkpoint's start,
1278  * but it's currently not deemed worth the effort.
1279  */
1281  if (pg_fsync(fd) != 0)
1282  ereport(ERROR,
1284  errmsg("could not fsync file \"%s\": %m", path)));
1286  CloseTransientFile(fd);
1287  }
1288  }
1289  FreeDir(mappings_dir);
1290 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
#define DEBUG1
Definition: elog.h:25
uint32 TransactionId
Definition: c.h:474
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
unsigned int Oid
Definition: postgres_ext.h:31
Definition: dirent.h:9
static int fd(const char *x, int i)
Definition: preproc-init.c:105
#define PG_BINARY
Definition: c.h:1080
Definition: dirent.c:25
#define ERROR
Definition: elog.h:43
int OpenTransientFile(const char *fileName, int fileFlags)
Definition: fd.c:2386
#define MAXPGPATH
int errcode_for_file_access(void)
Definition: elog.c:598
XLogRecPtr ReplicationSlotsComputeLogicalRestartLSN(void)
Definition: slot.c:784
unsigned int uint32
Definition: c.h:325
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2590
static void pgstat_report_wait_end(void)
Definition: pgstat.h:1260
#define ereport(elevel, rest)
Definition: elog.h:122
#define S_ISREG(m)
Definition: win32_port.h:310
int CloseTransientFile(int fd)
Definition: fd.c:2556
#define stat(a, b)
Definition: win32_port.h:266
uint64 XLogRecPtr
Definition: xlogdefs.h:21
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2656
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: pgstat.h:1236
XLogRecPtr GetRedoRecPtr(void)
Definition: xlog.c:8222
#define LOGICAL_REWRITE_FORMAT
Definition: rewriteheap.h:54
#define lstat(path, sb)
Definition: win32_port.h:255
int errmsg(const char *fmt,...)
Definition: elog.c:797
int pg_fsync(int fd)
Definition: fd.c:341
char d_name[MAX_PATH]
Definition: dirent.h:14
#define elog
Definition: elog.h:219
int FreeDir(DIR *dir)
Definition: fd.c:2708

◆ end_heap_rewrite()

void end_heap_rewrite ( RewriteState  state)

Definition at line 314 of file rewriteheap.c.

References hash_seq_init(), hash_seq_search(), heap_sync(), ItemPointerSetInvalid, log_newpage(), logical_end_heap_rewrite(), MAIN_FORKNUM, MemoryContextDelete(), PageSetChecksumInplace(), raw_heap_insert(), RelationData::rd_node, RelationData::rd_smgr, RelationNeedsWAL, RelationOpenSmgr, RewriteStateData::rs_blockno, RewriteStateData::rs_buffer, RewriteStateData::rs_buffer_valid, RewriteStateData::rs_cxt, RewriteStateData::rs_new_rel, RewriteStateData::rs_unresolved_tups, RewriteStateData::rs_use_wal, smgrextend(), HeapTupleHeaderData::t_ctid, HeapTupleData::t_data, and UnresolvedTupData::tuple.

Referenced by copy_heap_data().

315 {
316  HASH_SEQ_STATUS seq_status;
317  UnresolvedTup unresolved;
318 
319  /*
320  * Write any remaining tuples in the UnresolvedTups table. If we have any
321  * left, they should in fact be dead, but let's err on the safe side.
322  */
323  hash_seq_init(&seq_status, state->rs_unresolved_tups);
324 
325  while ((unresolved = hash_seq_search(&seq_status)) != NULL)
326  {
327  ItemPointerSetInvalid(&unresolved->tuple->t_data->t_ctid);
328  raw_heap_insert(state, unresolved->tuple);
329  }
330 
331  /* Write the last page, if any */
332  if (state->rs_buffer_valid)
333  {
334  if (state->rs_use_wal)
335  log_newpage(&state->rs_new_rel->rd_node,
336  MAIN_FORKNUM,
337  state->rs_blockno,
338  state->rs_buffer,
339  true);
341 
343 
345  (char *) state->rs_buffer, true);
346  }
347 
348  /*
349  * If the rel is WAL-logged, must fsync before commit. We use heap_sync
350  * to ensure that the toast table gets fsync'd too.
351  *
352  * It's obvious that we must do this when not WAL-logging. It's less
353  * obvious that we have to do it even if we did WAL-log the pages. The
354  * reason is the same as in tablecmds.c's copy_relation_data(): we're
355  * writing data that's not in shared buffers, and so a CHECKPOINT
356  * occurring during the rewriteheap operation won't have fsync'd data we
357  * wrote before the checkpoint.
358  */
359  if (RelationNeedsWAL(state->rs_new_rel))
360  heap_sync(state->rs_new_rel);
361 
363 
364  /* Deleting the context frees everything */
365  MemoryContextDelete(state->rs_cxt);
366 }
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:211
static void logical_end_heap_rewrite(RewriteState state)
Definition: rewriteheap.c:950
struct SMgrRelationData * rd_smgr
Definition: rel.h:57
Relation rs_new_rel
Definition: rewriteheap.c:144
void heap_sync(Relation rel)
Definition: heapam.c:9370
HeapTupleHeader t_data
Definition: htup.h:68
#define RelationOpenSmgr(relation)
Definition: rel.h:465
ItemPointerData t_ctid
Definition: htup_details.h:159
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:161
MemoryContext rs_cxt
Definition: rewriteheap.c:158
RelFileNode rd_node
Definition: rel.h:55
void PageSetChecksumInplace(Page page, BlockNumber blkno)
Definition: bufpage.c:1195
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1389
#define RelationNeedsWAL(relation)
Definition: rel.h:510
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1379
void smgrextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, char *buffer, bool skipFsync)
Definition: smgr.c:600
#define ItemPointerSetInvalid(pointer)
Definition: itemptr.h:172
XLogRecPtr log_newpage(RelFileNode *rnode, ForkNumber forkNum, BlockNumber blkno, Page page, bool page_std)
Definition: xloginsert.c:972
static void raw_heap_insert(RewriteState state, HeapTuple tup)
Definition: rewriteheap.c:632
BlockNumber rs_blockno
Definition: rewriteheap.c:146

◆ rewrite_heap_dead_tuple()

bool rewrite_heap_dead_tuple ( RewriteState  state,
HeapTuple  oldTuple 
)

Definition at line 582 of file rewriteheap.c.

References Assert, HASH_FIND, HASH_REMOVE, hash_search(), heap_freetuple(), HeapTupleHeaderGetXmin, RewriteStateData::rs_unresolved_tups, HeapTupleData::t_data, HeapTupleData::t_self, TidHashKey::tid, UnresolvedTupData::tuple, and TidHashKey::xmin.

Referenced by copy_heap_data().

583 {
584  /*
585  * If we have already seen an earlier tuple in the update chain that
586  * points to this tuple, let's forget about that earlier tuple. It's in
587  * fact dead as well, our simple xmax < OldestXmin test in
588  * HeapTupleSatisfiesVacuum just wasn't enough to detect it. It happens
589  * when xmin of a tuple is greater than xmax, which sounds
590  * counter-intuitive but is perfectly valid.
591  *
592  * We don't bother to try to detect the situation the other way round,
593  * when we encounter the dead tuple first and then the recently dead one
594  * that points to it. If that happens, we'll have some unmatched entries
595  * in the UnresolvedTups hash table at the end. That can happen anyway,
596  * because a vacuum might have removed the dead tuple in the chain before
597  * us.
598  */
599  UnresolvedTup unresolved;
600  TidHashKey hashkey;
601  bool found;
602 
603  memset(&hashkey, 0, sizeof(hashkey));
604  hashkey.xmin = HeapTupleHeaderGetXmin(old_tuple->t_data);
605  hashkey.tid = old_tuple->t_self;
606 
607  unresolved = hash_search(state->rs_unresolved_tups, &hashkey,
608  HASH_FIND, NULL);
609 
610  if (unresolved != NULL)
611  {
612  /* Need to free the contained tuple as well as the hashtable entry */
613  heap_freetuple(unresolved->tuple);
614  hash_search(state->rs_unresolved_tups, &hashkey,
615  HASH_REMOVE, &found);
616  Assert(found);
617  return true;
618  }
619 
620  return false;
621 }
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:906
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1773
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:161
ItemPointerData tid
Definition: rewriteheap.c:176
#define Assert(condition)
Definition: c.h:699
#define HeapTupleHeaderGetXmin(tup)
Definition: htup_details.h:312
TransactionId xmin
Definition: rewriteheap.c:175

◆ rewrite_heap_tuple()

void rewrite_heap_tuple ( RewriteState  state,
HeapTuple  oldTuple,
HeapTuple  newTuple 
)

Definition at line 380 of file rewriteheap.c.

References Assert, HASH_ENTER, HASH_FIND, HASH_REMOVE, hash_search(), HEAP2_XACT_MASK, heap_copytuple(), heap_freetuple(), heap_freeze_tuple(), HEAP_UPDATED, HEAP_XACT_MASK, HEAP_XMAX_INVALID, HeapTupleHeaderGetUpdateXid, HeapTupleHeaderGetXmin, HeapTupleHeaderIndicatesMovedPartitions, HeapTupleHeaderIsOnlyLocked(), ItemPointerEquals(), ItemPointerSetInvalid, logical_rewrite_heap_tuple(), MemoryContextSwitchTo(), OldToNewMappingData::new_tid, UnresolvedTupData::old_tid, raw_heap_insert(), RelationData::rd_rel, RewriteStateData::rs_cutoff_multi, RewriteStateData::rs_cxt, RewriteStateData::rs_freeze_xid, RewriteStateData::rs_old_new_tid_map, RewriteStateData::rs_old_rel, RewriteStateData::rs_oldest_xmin, RewriteStateData::rs_unresolved_tups, HeapTupleHeaderData::t_choice, HeapTupleHeaderData::t_ctid, HeapTupleData::t_data, HeapTupleHeaderData::t_heap, HeapTupleHeaderData::t_infomask, HeapTupleHeaderData::t_infomask2, HeapTupleData::t_self, TidHashKey::tid, TransactionIdPrecedes(), UnresolvedTupData::tuple, and TidHashKey::xmin.

Referenced by reform_and_rewrite_tuple().

382 {
383  MemoryContext old_cxt;
384  ItemPointerData old_tid;
385  TidHashKey hashkey;
386  bool found;
387  bool free_new;
388 
389  old_cxt = MemoryContextSwitchTo(state->rs_cxt);
390 
391  /*
392  * Copy the original tuple's visibility information into new_tuple.
393  *
394  * XXX we might later need to copy some t_infomask2 bits, too? Right now,
395  * we intentionally clear the HOT status bits.
396  */
397  memcpy(&new_tuple->t_data->t_choice.t_heap,
398  &old_tuple->t_data->t_choice.t_heap,
399  sizeof(HeapTupleFields));
400 
401  new_tuple->t_data->t_infomask &= ~HEAP_XACT_MASK;
402  new_tuple->t_data->t_infomask2 &= ~HEAP2_XACT_MASK;
403  new_tuple->t_data->t_infomask |=
404  old_tuple->t_data->t_infomask & HEAP_XACT_MASK;
405 
406  /*
407  * While we have our hands on the tuple, we may as well freeze any
408  * eligible xmin or xmax, so that future VACUUM effort can be saved.
409  */
410  heap_freeze_tuple(new_tuple->t_data,
411  state->rs_old_rel->rd_rel->relfrozenxid,
412  state->rs_old_rel->rd_rel->relminmxid,
413  state->rs_freeze_xid,
414  state->rs_cutoff_multi);
415 
416  /*
417  * Invalid ctid means that ctid should point to the tuple itself. We'll
418  * override it later if the tuple is part of an update chain.
419  */
420  ItemPointerSetInvalid(&new_tuple->t_data->t_ctid);
421 
422  /*
423  * If the tuple has been updated, check the old-to-new mapping hash table.
424  */
425  if (!((old_tuple->t_data->t_infomask & HEAP_XMAX_INVALID) ||
426  HeapTupleHeaderIsOnlyLocked(old_tuple->t_data)) &&
427  !HeapTupleHeaderIndicatesMovedPartitions(old_tuple->t_data) &&
428  !(ItemPointerEquals(&(old_tuple->t_self),
429  &(old_tuple->t_data->t_ctid))))
430  {
431  OldToNewMapping mapping;
432 
433  memset(&hashkey, 0, sizeof(hashkey));
434  hashkey.xmin = HeapTupleHeaderGetUpdateXid(old_tuple->t_data);
435  hashkey.tid = old_tuple->t_data->t_ctid;
436 
437  mapping = (OldToNewMapping)
438  hash_search(state->rs_old_new_tid_map, &hashkey,
439  HASH_FIND, NULL);
440 
441  if (mapping != NULL)
442  {
443  /*
444  * We've already copied the tuple that t_ctid points to, so we can
445  * set the ctid of this tuple to point to the new location, and
446  * insert it right away.
447  */
448  new_tuple->t_data->t_ctid = mapping->new_tid;
449 
450  /* We don't need the mapping entry anymore */
451  hash_search(state->rs_old_new_tid_map, &hashkey,
452  HASH_REMOVE, &found);
453  Assert(found);
454  }
455  else
456  {
457  /*
458  * We haven't seen the tuple t_ctid points to yet. Stash this
459  * tuple into unresolved_tups to be written later.
460  */
461  UnresolvedTup unresolved;
462 
463  unresolved = hash_search(state->rs_unresolved_tups, &hashkey,
464  HASH_ENTER, &found);
465  Assert(!found);
466 
467  unresolved->old_tid = old_tuple->t_self;
468  unresolved->tuple = heap_copytuple(new_tuple);
469 
470  /*
471  * We can't do anything more now, since we don't know where the
472  * tuple will be written.
473  */
474  MemoryContextSwitchTo(old_cxt);
475  return;
476  }
477  }
478 
479  /*
480  * Now we will write the tuple, and then check to see if it is the B tuple
481  * in any new or known pair. When we resolve a known pair, we will be
482  * able to write that pair's A tuple, and then we have to check if it
483  * resolves some other pair. Hence, we need a loop here.
484  */
485  old_tid = old_tuple->t_self;
486  free_new = false;
487 
488  for (;;)
489  {
490  ItemPointerData new_tid;
491 
492  /* Insert the tuple and find out where it's put in new_heap */
493  raw_heap_insert(state, new_tuple);
494  new_tid = new_tuple->t_self;
495 
496  logical_rewrite_heap_tuple(state, old_tid, new_tuple);
497 
498  /*
499  * If the tuple is the updated version of a row, and the prior version
500  * wouldn't be DEAD yet, then we need to either resolve the prior
501  * version (if it's waiting in rs_unresolved_tups), or make an entry
502  * in rs_old_new_tid_map (so we can resolve it when we do see it). The
503  * previous tuple's xmax would equal this one's xmin, so it's
504  * RECENTLY_DEAD if and only if the xmin is not before OldestXmin.
505  */
506  if ((new_tuple->t_data->t_infomask & HEAP_UPDATED) &&
507  !TransactionIdPrecedes(HeapTupleHeaderGetXmin(new_tuple->t_data),
508  state->rs_oldest_xmin))
509  {
510  /*
511  * Okay, this is B in an update pair. See if we've seen A.
512  */
513  UnresolvedTup unresolved;
514 
515  memset(&hashkey, 0, sizeof(hashkey));
516  hashkey.xmin = HeapTupleHeaderGetXmin(new_tuple->t_data);
517  hashkey.tid = old_tid;
518 
519  unresolved = hash_search(state->rs_unresolved_tups, &hashkey,
520  HASH_FIND, NULL);
521 
522  if (unresolved != NULL)
523  {
524  /*
525  * We have seen and memorized the previous tuple already. Now
526  * that we know where we inserted the tuple its t_ctid points
527  * to, fix its t_ctid and insert it to the new heap.
528  */
529  if (free_new)
530  heap_freetuple(new_tuple);
531  new_tuple = unresolved->tuple;
532  free_new = true;
533  old_tid = unresolved->old_tid;
534  new_tuple->t_data->t_ctid = new_tid;
535 
536  /*
537  * We don't need the hash entry anymore, but don't free its
538  * tuple just yet.
539  */
540  hash_search(state->rs_unresolved_tups, &hashkey,
541  HASH_REMOVE, &found);
542  Assert(found);
543 
544  /* loop back to insert the previous tuple in the chain */
545  continue;
546  }
547  else
548  {
549  /*
550  * Remember the new tid of this tuple. We'll use it to set the
551  * ctid when we find the previous tuple in the chain.
552  */
553  OldToNewMapping mapping;
554 
555  mapping = hash_search(state->rs_old_new_tid_map, &hashkey,
556  HASH_ENTER, &found);
557  Assert(!found);
558 
559  mapping->new_tid = new_tid;
560  }
561  }
562 
563  /* Done with this (chain of) tuples, for now */
564  if (free_new)
565  heap_freetuple(new_tuple);
566  break;
567  }
568 
569  MemoryContextSwitchTo(old_cxt);
570 }
#define HeapTupleHeaderGetUpdateXid(tup)
Definition: htup_details.h:364
bool HeapTupleHeaderIsOnlyLocked(HeapTupleHeader tuple)
Definition: tqual.c:1596
HeapTuple heap_copytuple(HeapTuple tuple)
Definition: heaptuple.c:722
static void logical_rewrite_heap_tuple(RewriteState state, ItemPointerData old_tid, HeapTuple new_tuple)
Definition: rewriteheap.c:1047
TransactionId rs_freeze_xid
Definition: rewriteheap.c:152
MultiXactId rs_cutoff_multi
Definition: rewriteheap.c:156
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
#define HEAP2_XACT_MASK
Definition: htup_details.h:282
#define HeapTupleHeaderIndicatesMovedPartitions(tup)
Definition: htup_details.h:444
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:906
#define HEAP_UPDATED
Definition: htup_details.h:208
ItemPointerData old_tid
Definition: rewriteheap.c:185
Form_pg_class rd_rel
Definition: rel.h:84
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1773
ItemPointerData new_tid
Definition: rewriteheap.c:194
#define HEAP_XMAX_INVALID
Definition: htup_details.h:206
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:161
bool heap_freeze_tuple(HeapTupleHeader tuple, TransactionId relfrozenxid, TransactionId relminmxid, TransactionId cutoff_xid, TransactionId cutoff_multi)
Definition: heapam.c:7043
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
TransactionId rs_oldest_xmin
Definition: rewriteheap.c:150
MemoryContext rs_cxt
Definition: rewriteheap.c:158
ItemPointerData tid
Definition: rewriteheap.c:176
#define Assert(condition)
Definition: c.h:699
HTAB * rs_old_new_tid_map
Definition: rewriteheap.c:162
#define HeapTupleHeaderGetXmin(tup)
Definition: htup_details.h:312
bool ItemPointerEquals(ItemPointer pointer1, ItemPointer pointer2)
Definition: itemptr.c:29
#define ItemPointerSetInvalid(pointer)
Definition: itemptr.h:172
TransactionId xmin
Definition: rewriteheap.c:175
static void raw_heap_insert(RewriteState state, HeapTuple tup)
Definition: rewriteheap.c:632
#define HEAP_XACT_MASK
Definition: htup_details.h:217
Relation rs_old_rel
Definition: rewriteheap.c:143
OldToNewMappingData * OldToNewMapping
Definition: rewriteheap.c:197