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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)
 
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

typedef struct RewriteStateData* 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 
)

Definition at line 237 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, and RewriteStateData::rs_unresolved_tups.

Referenced by heapam_relation_copy_for_cluster().

239 {
241  MemoryContext rw_cxt;
242  MemoryContext old_cxt;
243  HASHCTL hash_ctl;
244 
245  /*
246  * To ease cleanup, make a separate context that will contain the
247  * RewriteState struct itself plus all subsidiary data.
248  */
250  "Table rewrite",
252  old_cxt = MemoryContextSwitchTo(rw_cxt);
253 
254  /* Create and fill in the state struct */
255  state = palloc0(sizeof(RewriteStateData));
256 
257  state->rs_old_rel = old_heap;
258  state->rs_new_rel = new_heap;
259  state->rs_buffer = (Page) palloc(BLCKSZ);
260  /* new_heap needn't be empty, just locked */
261  state->rs_blockno = RelationGetNumberOfBlocks(new_heap);
262  state->rs_buffer_valid = false;
263  state->rs_oldest_xmin = oldest_xmin;
264  state->rs_freeze_xid = freeze_xid;
265  state->rs_cutoff_multi = cutoff_multi;
266  state->rs_cxt = rw_cxt;
267 
268  /* Initialize hash tables used to track update chains */
269  hash_ctl.keysize = sizeof(TidHashKey);
270  hash_ctl.entrysize = sizeof(UnresolvedTupData);
271  hash_ctl.hcxt = state->rs_cxt;
272 
273  state->rs_unresolved_tups =
274  hash_create("Rewrite / Unresolved ctids",
275  128, /* arbitrary initial size */
276  &hash_ctl,
278 
279  hash_ctl.entrysize = sizeof(OldToNewMappingData);
280 
281  state->rs_old_new_tid_map =
282  hash_create("Rewrite / Old to new tid map",
283  128, /* arbitrary initial size */
284  &hash_ctl,
286 
287  MemoryContextSwitchTo(old_cxt);
288 
290 
291  return state;
292 }
#define AllocSetContextCreate
Definition: memutils.h:173
#define HASH_CONTEXT
Definition: hsearch.h:102
#define HASH_ELEM
Definition: hsearch.h:95
MemoryContext hcxt
Definition: hsearch.h:86
TransactionId rs_freeze_xid
Definition: rewriteheap.c:142
MultiXactId rs_cutoff_multi
Definition: rewriteheap.c:146
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
Size entrysize
Definition: hsearch.h:76
Relation rs_new_rel
Definition: rewriteheap.c:135
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:151
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:195
HTAB * hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
Definition: dynahash.c:349
MemoryContext CurrentMemoryContext
Definition: mcxt.c:42
TransactionId rs_oldest_xmin
Definition: rewriteheap.c:140
#define HASH_BLOBS
Definition: hsearch.h:97
MemoryContext rs_cxt
Definition: rewriteheap.c:148
void * palloc0(Size size)
Definition: mcxt.c:1093
Size keysize
Definition: hsearch.h:75
#define RelationGetNumberOfBlocks(reln)
Definition: bufmgr.h:213
static void logical_begin_heap_rewrite(RewriteState state)
Definition: rewriteheap.c:801
HTAB * rs_old_new_tid_map
Definition: rewriteheap.c:152
Definition: regguts.h:317
void * palloc(Size size)
Definition: mcxt.c:1062
Relation rs_old_rel
Definition: rewriteheap.c:134
BlockNumber rs_blockno
Definition: rewriteheap.c:137
Pointer Page
Definition: bufpage.h:78

◆ CheckPointLogicalRewriteHeap()

void CheckPointLogicalRewriteHeap ( void  )

Definition at line 1199 of file rewriteheap.c.

References AllocateDir(), CloseTransientFile(), dirent::d_name, data_sync_elevel(), 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::st_mode, and WAIT_EVENT_LOGICAL_REWRITE_CHECKPOINT_SYNC.

Referenced by CheckPointGuts().

1200 {
1201  XLogRecPtr cutoff;
1202  XLogRecPtr redo;
1203  DIR *mappings_dir;
1204  struct dirent *mapping_de;
1205  char path[MAXPGPATH + 20];
1206 
1207  /*
1208  * We start of with a minimum of the last redo pointer. No new decoding
1209  * slot will start before that, so that's a safe upper bound for removal.
1210  */
1211  redo = GetRedoRecPtr();
1212 
1213  /* now check for the restart ptrs from existing slots */
1215 
1216  /* don't start earlier than the restart lsn */
1217  if (cutoff != InvalidXLogRecPtr && redo < cutoff)
1218  cutoff = redo;
1219 
1220  mappings_dir = AllocateDir("pg_logical/mappings");
1221  while ((mapping_de = ReadDir(mappings_dir, "pg_logical/mappings")) != NULL)
1222  {
1223  struct stat statbuf;
1224  Oid dboid;
1225  Oid relid;
1226  XLogRecPtr lsn;
1227  TransactionId rewrite_xid;
1228  TransactionId create_xid;
1229  uint32 hi,
1230  lo;
1231 
1232  if (strcmp(mapping_de->d_name, ".") == 0 ||
1233  strcmp(mapping_de->d_name, "..") == 0)
1234  continue;
1235 
1236  snprintf(path, sizeof(path), "pg_logical/mappings/%s", mapping_de->d_name);
1237  if (lstat(path, &statbuf) == 0 && !S_ISREG(statbuf.st_mode))
1238  continue;
1239 
1240  /* Skip over files that cannot be ours. */
1241  if (strncmp(mapping_de->d_name, "map-", 4) != 0)
1242  continue;
1243 
1244  if (sscanf(mapping_de->d_name, LOGICAL_REWRITE_FORMAT,
1245  &dboid, &relid, &hi, &lo, &rewrite_xid, &create_xid) != 6)
1246  elog(ERROR, "could not parse filename \"%s\"", mapping_de->d_name);
1247 
1248  lsn = ((uint64) hi) << 32 | lo;
1249 
1250  if (lsn < cutoff || cutoff == InvalidXLogRecPtr)
1251  {
1252  elog(DEBUG1, "removing logical rewrite file \"%s\"", path);
1253  if (unlink(path) < 0)
1254  ereport(ERROR,
1256  errmsg("could not remove file \"%s\": %m", path)));
1257  }
1258  else
1259  {
1260  /* on some operating systems fsyncing a file requires O_RDWR */
1261  int fd = OpenTransientFile(path, O_RDWR | PG_BINARY);
1262 
1263  /*
1264  * The file cannot vanish due to concurrency since this function
1265  * is the only one removing logical mappings and only one
1266  * checkpoint can be in progress at a time.
1267  */
1268  if (fd < 0)
1269  ereport(ERROR,
1271  errmsg("could not open file \"%s\": %m", path)));
1272 
1273  /*
1274  * We could try to avoid fsyncing files that either haven't
1275  * changed or have only been created since the checkpoint's start,
1276  * but it's currently not deemed worth the effort.
1277  */
1279  if (pg_fsync(fd) != 0)
1282  errmsg("could not fsync file \"%s\": %m", path)));
1284 
1285  if (CloseTransientFile(fd) != 0)
1286  ereport(ERROR,
1288  errmsg("could not close file \"%s\": %m", path)));
1289  }
1290  }
1291  FreeDir(mappings_dir);
1292 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
#define DEBUG1
Definition: elog.h:25
static void pgstat_report_wait_end(void)
Definition: wait_event.h:277
uint32 TransactionId
Definition: c.h:587
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:1271
Definition: dirent.c:25
#define ERROR
Definition: elog.h:46
int OpenTransientFile(const char *fileName, int fileFlags)
Definition: fd.c:2423
#define MAXPGPATH
int errcode_for_file_access(void)
Definition: elog.c:721
XLogRecPtr ReplicationSlotsComputeLogicalRestartLSN(void)
Definition: slot.c:884
unsigned int uint32
Definition: c.h:441
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2634
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: wait_event.h:261
#define S_ISREG(m)
Definition: win32_port.h:319
int CloseTransientFile(int fd)
Definition: fd.c:2600
int data_sync_elevel(int elevel)
Definition: fd.c:3714
#define ereport(elevel,...)
Definition: elog.h:157
uint64 XLogRecPtr
Definition: xlogdefs.h:21
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2700
XLogRecPtr GetRedoRecPtr(void)
Definition: xlog.c:8504
#define LOGICAL_REWRITE_FORMAT
Definition: rewriteheap.h:54
#define lstat(path, sb)
Definition: win32_port.h:276
int errmsg(const char *fmt,...)
Definition: elog.c:909
#define elog(elevel,...)
Definition: elog.h:232
int pg_fsync(int fd)
Definition: fd.c:352
char d_name[MAX_PATH]
Definition: dirent.h:15
#define snprintf
Definition: port.h:216
int FreeDir(DIR *dir)
Definition: fd.c:2752

◆ end_heap_rewrite()

void end_heap_rewrite ( RewriteState  state)

Definition at line 300 of file rewriteheap.c.

References hash_seq_init(), hash_seq_search(), 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, smgrextend(), smgrimmedsync(), HeapTupleHeaderData::t_ctid, HeapTupleData::t_data, and UnresolvedTupData::tuple.

Referenced by heapam_relation_copy_for_cluster().

301 {
302  HASH_SEQ_STATUS seq_status;
303  UnresolvedTup unresolved;
304 
305  /*
306  * Write any remaining tuples in the UnresolvedTups table. If we have any
307  * left, they should in fact be dead, but let's err on the safe side.
308  */
309  hash_seq_init(&seq_status, state->rs_unresolved_tups);
310 
311  while ((unresolved = hash_seq_search(&seq_status)) != NULL)
312  {
313  ItemPointerSetInvalid(&unresolved->tuple->t_data->t_ctid);
314  raw_heap_insert(state, unresolved->tuple);
315  }
316 
317  /* Write the last page, if any */
318  if (state->rs_buffer_valid)
319  {
320  if (RelationNeedsWAL(state->rs_new_rel))
321  log_newpage(&state->rs_new_rel->rd_node,
322  MAIN_FORKNUM,
323  state->rs_blockno,
324  state->rs_buffer,
325  true);
326 
328 
331  (char *) state->rs_buffer, true);
332  }
333 
334  /*
335  * When we WAL-logged rel pages, we must nonetheless fsync them. The
336  * reason is the same as in storage.c's RelationCopyStorage(): we're
337  * writing data that's not in shared buffers, and so a CHECKPOINT
338  * occurring during the rewriteheap operation won't have fsync'd data we
339  * wrote before the checkpoint.
340  */
341  if (RelationNeedsWAL(state->rs_new_rel))
342  {
343  /* for an empty table, this could be first smgr access */
346  }
347 
349 
350  /* Deleting the context frees everything */
351  MemoryContextDelete(state->rs_cxt);
352 }
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:218
static void logical_end_heap_rewrite(RewriteState state)
Definition: rewriteheap.c:947
struct SMgrRelationData * rd_smgr
Definition: rel.h:57
Relation rs_new_rel
Definition: rewriteheap.c:135
HeapTupleHeader t_data
Definition: htup.h:68
#define RelationOpenSmgr(relation)
Definition: rel.h:526
ItemPointerData t_ctid
Definition: htup_details.h:160
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:151
MemoryContext rs_cxt
Definition: rewriteheap.c:148
RelFileNode rd_node
Definition: rel.h:55
void PageSetChecksumInplace(Page page, BlockNumber blkno)
Definition: bufpage.c:1532
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1436
#define RelationNeedsWAL(relation)
Definition: rel.h:582
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1426
void smgrextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum, char *buffer, bool skipFsync)
Definition: smgr.c:462
#define ItemPointerSetInvalid(pointer)
Definition: itemptr.h:172
XLogRecPtr log_newpage(RelFileNode *rnode, ForkNumber forkNum, BlockNumber blkno, Page page, bool page_std)
Definition: xloginsert.c:996
static void raw_heap_insert(RewriteState state, HeapTuple tup)
Definition: rewriteheap.c:618
BlockNumber rs_blockno
Definition: rewriteheap.c:137
void smgrimmedsync(SMgrRelation reln, ForkNumber forknum)
Definition: smgr.c:660

◆ rewrite_heap_dead_tuple()

bool rewrite_heap_dead_tuple ( RewriteState  state,
HeapTuple  oldTuple 
)

Definition at line 568 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 heapam_relation_copy_for_cluster().

569 {
570  /*
571  * If we have already seen an earlier tuple in the update chain that
572  * points to this tuple, let's forget about that earlier tuple. It's in
573  * fact dead as well, our simple xmax < OldestXmin test in
574  * HeapTupleSatisfiesVacuum just wasn't enough to detect it. It happens
575  * when xmin of a tuple is greater than xmax, which sounds
576  * counter-intuitive but is perfectly valid.
577  *
578  * We don't bother to try to detect the situation the other way round,
579  * when we encounter the dead tuple first and then the recently dead one
580  * that points to it. If that happens, we'll have some unmatched entries
581  * in the UnresolvedTups hash table at the end. That can happen anyway,
582  * because a vacuum might have removed the dead tuple in the chain before
583  * us.
584  */
585  UnresolvedTup unresolved;
586  TidHashKey hashkey;
587  bool found;
588 
589  memset(&hashkey, 0, sizeof(hashkey));
590  hashkey.xmin = HeapTupleHeaderGetXmin(old_tuple->t_data);
591  hashkey.tid = old_tuple->t_self;
592 
593  unresolved = hash_search(state->rs_unresolved_tups, &hashkey,
594  HASH_FIND, NULL);
595 
596  if (unresolved != NULL)
597  {
598  /* Need to free the contained tuple as well as the hashtable entry */
599  heap_freetuple(unresolved->tuple);
600  hash_search(state->rs_unresolved_tups, &hashkey,
601  HASH_REMOVE, &found);
602  Assert(found);
603  return true;
604  }
605 
606  return false;
607 }
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:954
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:151
ItemPointerData tid
Definition: rewriteheap.c:166
#define Assert(condition)
Definition: c.h:804
#define HeapTupleHeaderGetXmin(tup)
Definition: htup_details.h:313
TransactionId xmin
Definition: rewriteheap.c:165

◆ rewrite_heap_tuple()

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

Definition at line 366 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().

368 {
369  MemoryContext old_cxt;
370  ItemPointerData old_tid;
371  TidHashKey hashkey;
372  bool found;
373  bool free_new;
374 
375  old_cxt = MemoryContextSwitchTo(state->rs_cxt);
376 
377  /*
378  * Copy the original tuple's visibility information into new_tuple.
379  *
380  * XXX we might later need to copy some t_infomask2 bits, too? Right now,
381  * we intentionally clear the HOT status bits.
382  */
383  memcpy(&new_tuple->t_data->t_choice.t_heap,
384  &old_tuple->t_data->t_choice.t_heap,
385  sizeof(HeapTupleFields));
386 
387  new_tuple->t_data->t_infomask &= ~HEAP_XACT_MASK;
388  new_tuple->t_data->t_infomask2 &= ~HEAP2_XACT_MASK;
389  new_tuple->t_data->t_infomask |=
390  old_tuple->t_data->t_infomask & HEAP_XACT_MASK;
391 
392  /*
393  * While we have our hands on the tuple, we may as well freeze any
394  * eligible xmin or xmax, so that future VACUUM effort can be saved.
395  */
396  heap_freeze_tuple(new_tuple->t_data,
397  state->rs_old_rel->rd_rel->relfrozenxid,
398  state->rs_old_rel->rd_rel->relminmxid,
399  state->rs_freeze_xid,
400  state->rs_cutoff_multi);
401 
402  /*
403  * Invalid ctid means that ctid should point to the tuple itself. We'll
404  * override it later if the tuple is part of an update chain.
405  */
406  ItemPointerSetInvalid(&new_tuple->t_data->t_ctid);
407 
408  /*
409  * If the tuple has been updated, check the old-to-new mapping hash table.
410  */
411  if (!((old_tuple->t_data->t_infomask & HEAP_XMAX_INVALID) ||
412  HeapTupleHeaderIsOnlyLocked(old_tuple->t_data)) &&
413  !HeapTupleHeaderIndicatesMovedPartitions(old_tuple->t_data) &&
414  !(ItemPointerEquals(&(old_tuple->t_self),
415  &(old_tuple->t_data->t_ctid))))
416  {
417  OldToNewMapping mapping;
418 
419  memset(&hashkey, 0, sizeof(hashkey));
420  hashkey.xmin = HeapTupleHeaderGetUpdateXid(old_tuple->t_data);
421  hashkey.tid = old_tuple->t_data->t_ctid;
422 
423  mapping = (OldToNewMapping)
424  hash_search(state->rs_old_new_tid_map, &hashkey,
425  HASH_FIND, NULL);
426 
427  if (mapping != NULL)
428  {
429  /*
430  * We've already copied the tuple that t_ctid points to, so we can
431  * set the ctid of this tuple to point to the new location, and
432  * insert it right away.
433  */
434  new_tuple->t_data->t_ctid = mapping->new_tid;
435 
436  /* We don't need the mapping entry anymore */
437  hash_search(state->rs_old_new_tid_map, &hashkey,
438  HASH_REMOVE, &found);
439  Assert(found);
440  }
441  else
442  {
443  /*
444  * We haven't seen the tuple t_ctid points to yet. Stash this
445  * tuple into unresolved_tups to be written later.
446  */
447  UnresolvedTup unresolved;
448 
449  unresolved = hash_search(state->rs_unresolved_tups, &hashkey,
450  HASH_ENTER, &found);
451  Assert(!found);
452 
453  unresolved->old_tid = old_tuple->t_self;
454  unresolved->tuple = heap_copytuple(new_tuple);
455 
456  /*
457  * We can't do anything more now, since we don't know where the
458  * tuple will be written.
459  */
460  MemoryContextSwitchTo(old_cxt);
461  return;
462  }
463  }
464 
465  /*
466  * Now we will write the tuple, and then check to see if it is the B tuple
467  * in any new or known pair. When we resolve a known pair, we will be
468  * able to write that pair's A tuple, and then we have to check if it
469  * resolves some other pair. Hence, we need a loop here.
470  */
471  old_tid = old_tuple->t_self;
472  free_new = false;
473 
474  for (;;)
475  {
476  ItemPointerData new_tid;
477 
478  /* Insert the tuple and find out where it's put in new_heap */
479  raw_heap_insert(state, new_tuple);
480  new_tid = new_tuple->t_self;
481 
482  logical_rewrite_heap_tuple(state, old_tid, new_tuple);
483 
484  /*
485  * If the tuple is the updated version of a row, and the prior version
486  * wouldn't be DEAD yet, then we need to either resolve the prior
487  * version (if it's waiting in rs_unresolved_tups), or make an entry
488  * in rs_old_new_tid_map (so we can resolve it when we do see it). The
489  * previous tuple's xmax would equal this one's xmin, so it's
490  * RECENTLY_DEAD if and only if the xmin is not before OldestXmin.
491  */
492  if ((new_tuple->t_data->t_infomask & HEAP_UPDATED) &&
493  !TransactionIdPrecedes(HeapTupleHeaderGetXmin(new_tuple->t_data),
494  state->rs_oldest_xmin))
495  {
496  /*
497  * Okay, this is B in an update pair. See if we've seen A.
498  */
499  UnresolvedTup unresolved;
500 
501  memset(&hashkey, 0, sizeof(hashkey));
502  hashkey.xmin = HeapTupleHeaderGetXmin(new_tuple->t_data);
503  hashkey.tid = old_tid;
504 
505  unresolved = hash_search(state->rs_unresolved_tups, &hashkey,
506  HASH_FIND, NULL);
507 
508  if (unresolved != NULL)
509  {
510  /*
511  * We have seen and memorized the previous tuple already. Now
512  * that we know where we inserted the tuple its t_ctid points
513  * to, fix its t_ctid and insert it to the new heap.
514  */
515  if (free_new)
516  heap_freetuple(new_tuple);
517  new_tuple = unresolved->tuple;
518  free_new = true;
519  old_tid = unresolved->old_tid;
520  new_tuple->t_data->t_ctid = new_tid;
521 
522  /*
523  * We don't need the hash entry anymore, but don't free its
524  * tuple just yet.
525  */
526  hash_search(state->rs_unresolved_tups, &hashkey,
527  HASH_REMOVE, &found);
528  Assert(found);
529 
530  /* loop back to insert the previous tuple in the chain */
531  continue;
532  }
533  else
534  {
535  /*
536  * Remember the new tid of this tuple. We'll use it to set the
537  * ctid when we find the previous tuple in the chain.
538  */
539  OldToNewMapping mapping;
540 
541  mapping = hash_search(state->rs_old_new_tid_map, &hashkey,
542  HASH_ENTER, &found);
543  Assert(!found);
544 
545  mapping->new_tid = new_tid;
546  }
547  }
548 
549  /* Done with this (chain of) tuples, for now */
550  if (free_new)
551  heap_freetuple(new_tuple);
552  break;
553  }
554 
555  MemoryContextSwitchTo(old_cxt);
556 }
#define HeapTupleHeaderGetUpdateXid(tup)
Definition: htup_details.h:365
HeapTuple heap_copytuple(HeapTuple tuple)
Definition: heaptuple.c:680
static void logical_rewrite_heap_tuple(RewriteState state, ItemPointerData old_tid, HeapTuple new_tuple)
Definition: rewriteheap.c:1043
TransactionId rs_freeze_xid
Definition: rewriteheap.c:142
bool HeapTupleHeaderIsOnlyLocked(HeapTupleHeader tuple)
MultiXactId rs_cutoff_multi
Definition: rewriteheap.c:146
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
#define HEAP2_XACT_MASK
Definition: htup_details.h:283
#define HeapTupleHeaderIndicatesMovedPartitions(tup)
Definition: htup_details.h:445
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:954
#define HEAP_UPDATED
Definition: htup_details.h:209
ItemPointerData old_tid
Definition: rewriteheap.c:175
Form_pg_class rd_rel
Definition: rel.h:109
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
ItemPointerData new_tid
Definition: rewriteheap.c:184
#define HEAP_XMAX_INVALID
Definition: htup_details.h:207
HTAB * rs_unresolved_tups
Definition: rewriteheap.c:151
bool heap_freeze_tuple(HeapTupleHeader tuple, TransactionId relfrozenxid, TransactionId relminmxid, TransactionId cutoff_xid, TransactionId cutoff_multi)
Definition: heapam.c:6720
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
TransactionId rs_oldest_xmin
Definition: rewriteheap.c:140
MemoryContext rs_cxt
Definition: rewriteheap.c:148
ItemPointerData tid
Definition: rewriteheap.c:166
#define Assert(condition)
Definition: c.h:804
HTAB * rs_old_new_tid_map
Definition: rewriteheap.c:152
#define HeapTupleHeaderGetXmin(tup)
Definition: htup_details.h:313
bool ItemPointerEquals(ItemPointer pointer1, ItemPointer pointer2)
Definition: itemptr.c:29
#define ItemPointerSetInvalid(pointer)
Definition: itemptr.h:172
TransactionId xmin
Definition: rewriteheap.c:165
static void raw_heap_insert(RewriteState state, HeapTuple tup)
Definition: rewriteheap.c:618
#define HEAP_XACT_MASK
Definition: htup_details.h:218
Relation rs_old_rel
Definition: rewriteheap.c:134
OldToNewMappingData * OldToNewMapping
Definition: rewriteheap.c:187