PostgreSQL Source Code  git master
genam.c File Reference
#include "postgres.h"
#include "access/genam.h"
#include "access/relscan.h"
#include "access/tableam.h"
#include "access/transam.h"
#include "catalog/index.h"
#include "lib/stringinfo.h"
#include "miscadmin.h"
#include "storage/bufmgr.h"
#include "storage/procarray.h"
#include "utils/acl.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/rls.h"
#include "utils/ruleutils.h"
#include "utils/snapmgr.h"
Include dependency graph for genam.c:

Go to the source code of this file.

Functions

IndexScanDesc RelationGetIndexScan (Relation indexRelation, int nkeys, int norderbys)
 
void IndexScanEnd (IndexScanDesc scan)
 
char * BuildIndexValueDescription (Relation indexRelation, const Datum *values, const bool *isnull)
 
TransactionId index_compute_xid_horizon_for_tuples (Relation irel, Relation hrel, Buffer ibuf, OffsetNumber *itemnos, int nitems)
 
SysScanDesc systable_beginscan (Relation heapRelation, Oid indexId, bool indexOK, Snapshot snapshot, int nkeys, ScanKey key)
 
static void HandleConcurrentAbort ()
 
HeapTuple systable_getnext (SysScanDesc sysscan)
 
bool systable_recheck_tuple (SysScanDesc sysscan, HeapTuple tup)
 
void systable_endscan (SysScanDesc sysscan)
 
SysScanDesc systable_beginscan_ordered (Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, ScanKey key)
 
HeapTuple systable_getnext_ordered (SysScanDesc sysscan, ScanDirection direction)
 
void systable_endscan_ordered (SysScanDesc sysscan)
 

Function Documentation

◆ BuildIndexValueDescription()

char* BuildIndexValueDescription ( Relation  indexRelation,
const Datum values,
const bool isnull 
)

Definition at line 174 of file genam.c.

176 {
178  Form_pg_index idxrec;
179  int indnkeyatts;
180  int i;
181  int keyno;
182  Oid indexrelid = RelationGetRelid(indexRelation);
183  Oid indrelid;
184  AclResult aclresult;
185 
186  indnkeyatts = IndexRelationGetNumberOfKeyAttributes(indexRelation);
187 
188  /*
189  * Check permissions- if the user does not have access to view all of the
190  * key columns then return NULL to avoid leaking data.
191  *
192  * First check if RLS is enabled for the relation. If so, return NULL to
193  * avoid leaking data.
194  *
195  * Next we need to check table-level SELECT access and then, if there is
196  * no access there, check column-level permissions.
197  */
198  idxrec = indexRelation->rd_index;
199  indrelid = idxrec->indrelid;
200  Assert(indexrelid == idxrec->indexrelid);
201 
202  /* RLS check- if RLS is enabled then we don't return anything. */
203  if (check_enable_rls(indrelid, InvalidOid, true) == RLS_ENABLED)
204  return NULL;
205 
206  /* Table-level SELECT is enough, if the user has it */
207  aclresult = pg_class_aclcheck(indrelid, GetUserId(), ACL_SELECT);
208  if (aclresult != ACLCHECK_OK)
209  {
210  /*
211  * No table-level access, so step through the columns in the index and
212  * make sure the user has SELECT rights on all of them.
213  */
214  for (keyno = 0; keyno < indnkeyatts; keyno++)
215  {
216  AttrNumber attnum = idxrec->indkey.values[keyno];
217 
218  /*
219  * Note that if attnum == InvalidAttrNumber, then this is an index
220  * based on an expression and we return no detail rather than try
221  * to figure out what column(s) the expression includes and if the
222  * user has SELECT rights on them.
223  */
224  if (attnum == InvalidAttrNumber ||
227  {
228  /* No access, so clean up and return */
229  return NULL;
230  }
231  }
232  }
233 
235  appendStringInfo(&buf, "(%s)=(",
236  pg_get_indexdef_columns(indexrelid, true));
237 
238  for (i = 0; i < indnkeyatts; i++)
239  {
240  char *val;
241 
242  if (isnull[i])
243  val = "null";
244  else
245  {
246  Oid foutoid;
247  bool typisvarlena;
248 
249  /*
250  * The provided data is not necessarily of the type stored in the
251  * index; rather it is of the index opclass's input type. So look
252  * at rd_opcintype not the index tupdesc.
253  *
254  * Note: this is a bit shaky for opclasses that have pseudotype
255  * input types such as ANYARRAY or RECORD. Currently, the
256  * typoutput functions associated with the pseudotypes will work
257  * okay, but we might have to try harder in future.
258  */
259  getTypeOutputInfo(indexRelation->rd_opcintype[i],
260  &foutoid, &typisvarlena);
261  val = OidOutputFunctionCall(foutoid, values[i]);
262  }
263 
264  if (i > 0)
265  appendStringInfoString(&buf, ", ");
267  }
268 
269  appendStringInfoChar(&buf, ')');
270 
271  return buf.data;
272 }
AclResult
Definition: acl.h:182
@ ACLCHECK_OK
Definition: acl.h:183
AclResult pg_attribute_aclcheck(Oid table_oid, AttrNumber attnum, Oid roleid, AclMode mode)
Definition: aclchk.c:3920
AclResult pg_class_aclcheck(Oid table_oid, Oid roleid, AclMode mode)
Definition: aclchk.c:4091
int16 AttrNumber
Definition: attnum.h:21
#define InvalidAttrNumber
Definition: attnum.h:23
static Datum values[MAXATTR]
Definition: bootstrap.c:150
#define Assert(condition)
Definition: c.h:858
char * OidOutputFunctionCall(Oid functionId, Datum val)
Definition: fmgr.c:1763
long val
Definition: informix.c:670
int i
Definition: isn.c:73
void getTypeOutputInfo(Oid type, Oid *typOutput, bool *typIsVarlena)
Definition: lsyscache.c:2907
Oid GetUserId(void)
Definition: miscinit.c:514
#define ACL_SELECT
Definition: parsenodes.h:77
int16 attnum
Definition: pg_attribute.h:74
FormData_pg_index * Form_pg_index
Definition: pg_index.h:70
static char * buf
Definition: pg_test_fsync.c:73
#define InvalidOid
Definition: postgres_ext.h:36
unsigned int Oid
Definition: postgres_ext.h:31
#define RelationGetRelid(relation)
Definition: rel.h:505
#define IndexRelationGetNumberOfKeyAttributes(relation)
Definition: rel.h:524
int check_enable_rls(Oid relid, Oid checkAsUser, bool noError)
Definition: rls.c:52
@ RLS_ENABLED
Definition: rls.h:45
char * pg_get_indexdef_columns(Oid indexrelid, bool pretty)
Definition: ruleutils.c:1219
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:97
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:182
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:194
void initStringInfo(StringInfo str)
Definition: stringinfo.c:59
Oid * rd_opcintype
Definition: rel.h:208
Form_pg_index rd_index
Definition: rel.h:192

References ACL_SELECT, ACLCHECK_OK, appendStringInfo(), appendStringInfoChar(), appendStringInfoString(), Assert, attnum, buf, check_enable_rls(), getTypeOutputInfo(), GetUserId(), i, IndexRelationGetNumberOfKeyAttributes, initStringInfo(), InvalidAttrNumber, InvalidOid, OidOutputFunctionCall(), pg_attribute_aclcheck(), pg_class_aclcheck(), pg_get_indexdef_columns(), RelationData::rd_index, RelationData::rd_opcintype, RelationGetRelid, RLS_ENABLED, val, and values.

Referenced by _bt_check_unique(), check_exclusion_or_unique_constraint(), and comparetup_index_btree_tiebreak().

◆ HandleConcurrentAbort()

static void HandleConcurrentAbort ( )
inlinestatic

Definition at line 480 of file genam.c.

481 {
485  ereport(ERROR,
486  (errcode(ERRCODE_TRANSACTION_ROLLBACK),
487  errmsg("transaction aborted during system catalog scan")));
488 }
int errcode(int sqlerrcode)
Definition: elog.c:855
int errmsg(const char *fmt,...)
Definition: elog.c:1072
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:149
bool TransactionIdIsInProgress(TransactionId xid)
Definition: procarray.c:1402
bool TransactionIdDidCommit(TransactionId transactionId)
Definition: transam.c:126
#define TransactionIdIsValid(xid)
Definition: transam.h:41
TransactionId CheckXidAlive
Definition: xact.c:97

References CheckXidAlive, ereport, errcode(), errmsg(), ERROR, TransactionIdDidCommit(), TransactionIdIsInProgress(), and TransactionIdIsValid.

Referenced by systable_getnext(), systable_getnext_ordered(), and systable_recheck_tuple().

◆ index_compute_xid_horizon_for_tuples()

TransactionId index_compute_xid_horizon_for_tuples ( Relation  irel,
Relation  hrel,
Buffer  ibuf,
OffsetNumber itemnos,
int  nitems 
)

Definition at line 291 of file genam.c.

296 {
297  TM_IndexDeleteOp delstate;
298  TransactionId snapshotConflictHorizon = InvalidTransactionId;
299  Page ipage = BufferGetPage(ibuf);
300  IndexTuple itup;
301 
302  Assert(nitems > 0);
303 
304  delstate.irel = irel;
305  delstate.iblknum = BufferGetBlockNumber(ibuf);
306  delstate.bottomup = false;
307  delstate.bottomupfreespace = 0;
308  delstate.ndeltids = 0;
309  delstate.deltids = palloc(nitems * sizeof(TM_IndexDelete));
310  delstate.status = palloc(nitems * sizeof(TM_IndexStatus));
311 
312  /* identify what the index tuples about to be deleted point to */
313  for (int i = 0; i < nitems; i++)
314  {
315  OffsetNumber offnum = itemnos[i];
316  ItemId iitemid;
317 
318  iitemid = PageGetItemId(ipage, offnum);
319  itup = (IndexTuple) PageGetItem(ipage, iitemid);
320 
321  Assert(ItemIdIsDead(iitemid));
322 
323  ItemPointerCopy(&itup->t_tid, &delstate.deltids[i].tid);
324  delstate.deltids[i].id = delstate.ndeltids;
325  delstate.status[i].idxoffnum = offnum;
326  delstate.status[i].knowndeletable = true; /* LP_DEAD-marked */
327  delstate.status[i].promising = false; /* unused */
328  delstate.status[i].freespace = 0; /* unused */
329 
330  delstate.ndeltids++;
331  }
332 
333  /* determine the actual xid horizon */
334  snapshotConflictHorizon = table_index_delete_tuples(hrel, &delstate);
335 
336  /* assert tableam agrees that all items are deletable */
337  Assert(delstate.ndeltids == nitems);
338 
339  pfree(delstate.deltids);
340  pfree(delstate.status);
341 
342  return snapshotConflictHorizon;
343 }
BlockNumber BufferGetBlockNumber(Buffer buffer)
Definition: bufmgr.c:3736
static Page BufferGetPage(Buffer buffer)
Definition: bufmgr.h:400
Pointer Page
Definition: bufpage.h:78
static Item PageGetItem(Page page, ItemId itemId)
Definition: bufpage.h:351
static ItemId PageGetItemId(Page page, OffsetNumber offsetNumber)
Definition: bufpage.h:240
uint32 TransactionId
Definition: c.h:652
#define nitems(x)
Definition: indent.h:31
#define ItemIdIsDead(itemId)
Definition: itemid.h:113
static void ItemPointerCopy(const ItemPointerData *fromPointer, ItemPointerData *toPointer)
Definition: itemptr.h:172
IndexTupleData * IndexTuple
Definition: itup.h:53
void pfree(void *pointer)
Definition: mcxt.c:1521
void * palloc(Size size)
Definition: mcxt.c:1317
uint16 OffsetNumber
Definition: off.h:24
ItemPointerData t_tid
Definition: itup.h:37
TM_IndexStatus * status
Definition: tableam.h:255
int bottomupfreespace
Definition: tableam.h:250
Relation irel
Definition: tableam.h:247
TM_IndexDelete * deltids
Definition: tableam.h:254
BlockNumber iblknum
Definition: tableam.h:248
ItemPointerData tid
Definition: tableam.h:213
bool knowndeletable
Definition: tableam.h:220
bool promising
Definition: tableam.h:223
int16 freespace
Definition: tableam.h:224
OffsetNumber idxoffnum
Definition: tableam.h:219
static TransactionId table_index_delete_tuples(Relation rel, TM_IndexDeleteOp *delstate)
Definition: tableam.h:1356
#define InvalidTransactionId
Definition: transam.h:31

References Assert, TM_IndexDeleteOp::bottomup, TM_IndexDeleteOp::bottomupfreespace, BufferGetBlockNumber(), BufferGetPage(), TM_IndexDeleteOp::deltids, TM_IndexStatus::freespace, i, TM_IndexDeleteOp::iblknum, TM_IndexDelete::id, TM_IndexStatus::idxoffnum, InvalidTransactionId, TM_IndexDeleteOp::irel, ItemIdIsDead, ItemPointerCopy(), TM_IndexStatus::knowndeletable, TM_IndexDeleteOp::ndeltids, nitems, PageGetItem(), PageGetItemId(), palloc(), pfree(), TM_IndexStatus::promising, TM_IndexDeleteOp::status, IndexTupleData::t_tid, table_index_delete_tuples(), and TM_IndexDelete::tid.

Referenced by _hash_vacuum_one_page(), and gistprunepage().

◆ IndexScanEnd()

void IndexScanEnd ( IndexScanDesc  scan)

Definition at line 142 of file genam.c.

143 {
144  if (scan->keyData != NULL)
145  pfree(scan->keyData);
146  if (scan->orderByData != NULL)
147  pfree(scan->orderByData);
148 
149  pfree(scan);
150 }
struct ScanKeyData * keyData
Definition: relscan.h:122
struct ScanKeyData * orderByData
Definition: relscan.h:123

References IndexScanDescData::keyData, IndexScanDescData::orderByData, and pfree().

Referenced by index_endscan().

◆ RelationGetIndexScan()

IndexScanDesc RelationGetIndexScan ( Relation  indexRelation,
int  nkeys,
int  norderbys 
)

Definition at line 78 of file genam.c.

79 {
80  IndexScanDesc scan;
81 
82  scan = (IndexScanDesc) palloc(sizeof(IndexScanDescData));
83 
84  scan->heapRelation = NULL; /* may be set later */
85  scan->xs_heapfetch = NULL;
86  scan->indexRelation = indexRelation;
87  scan->xs_snapshot = InvalidSnapshot; /* caller must initialize this */
88  scan->numberOfKeys = nkeys;
89  scan->numberOfOrderBys = norderbys;
90 
91  /*
92  * We allocate key workspace here, but it won't get filled until amrescan.
93  */
94  if (nkeys > 0)
95  scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * nkeys);
96  else
97  scan->keyData = NULL;
98  if (norderbys > 0)
99  scan->orderByData = (ScanKey) palloc(sizeof(ScanKeyData) * norderbys);
100  else
101  scan->orderByData = NULL;
102 
103  scan->xs_want_itup = false; /* may be set later */
104 
105  /*
106  * During recovery we ignore killed tuples and don't bother to kill them
107  * either. We do this because the xmin on the primary node could easily be
108  * later than the xmin on the standby node, so that what the primary
109  * thinks is killed is supposed to be visible on standby. So for correct
110  * MVCC for queries during recovery we must ignore these hints and check
111  * all tuples. Do *not* set ignore_killed_tuples to true when running in a
112  * transaction that was started during recovery. xactStartedInRecovery
113  * should not be altered by index AMs.
114  */
115  scan->kill_prior_tuple = false;
118 
119  scan->opaque = NULL;
120 
121  scan->xs_itup = NULL;
122  scan->xs_itupdesc = NULL;
123  scan->xs_hitup = NULL;
124  scan->xs_hitupdesc = NULL;
125 
126  return scan;
127 }
struct IndexScanDescData * IndexScanDesc
Definition: genam.h:90
ScanKeyData * ScanKey
Definition: skey.h:75
#define InvalidSnapshot
Definition: snapshot.h:123
HeapTuple xs_hitup
Definition: relscan.h:144
bool ignore_killed_tuples
Definition: relscan.h:129
IndexFetchTableData * xs_heapfetch
Definition: relscan.h:150
int numberOfOrderBys
Definition: relscan.h:121
bool xactStartedInRecovery
Definition: relscan.h:130
IndexTuple xs_itup
Definition: relscan.h:142
bool kill_prior_tuple
Definition: relscan.h:128
struct TupleDescData * xs_hitupdesc
Definition: relscan.h:145
struct TupleDescData * xs_itupdesc
Definition: relscan.h:143
Relation indexRelation
Definition: relscan.h:118
struct SnapshotData * xs_snapshot
Definition: relscan.h:119
Relation heapRelation
Definition: relscan.h:117
bool TransactionStartedDuringRecovery(void)
Definition: xact.c:1040

References IndexScanDescData::heapRelation, IndexScanDescData::ignore_killed_tuples, IndexScanDescData::indexRelation, InvalidSnapshot, IndexScanDescData::keyData, IndexScanDescData::kill_prior_tuple, IndexScanDescData::numberOfKeys, IndexScanDescData::numberOfOrderBys, IndexScanDescData::opaque, IndexScanDescData::orderByData, palloc(), TransactionStartedDuringRecovery(), IndexScanDescData::xactStartedInRecovery, IndexScanDescData::xs_heapfetch, IndexScanDescData::xs_hitup, IndexScanDescData::xs_hitupdesc, IndexScanDescData::xs_itup, IndexScanDescData::xs_itupdesc, IndexScanDescData::xs_snapshot, and IndexScanDescData::xs_want_itup.

Referenced by blbeginscan(), brinbeginscan(), btbeginscan(), dibeginscan(), ginbeginscan(), gistbeginscan(), hashbeginscan(), and spgbeginscan().

◆ systable_beginscan()

SysScanDesc systable_beginscan ( Relation  heapRelation,
Oid  indexId,
bool  indexOK,
Snapshot  snapshot,
int  nkeys,
ScanKey  key 
)

Definition at line 384 of file genam.c.

389 {
390  SysScanDesc sysscan;
391  Relation irel;
392 
393  if (indexOK &&
395  !ReindexIsProcessingIndex(indexId))
396  irel = index_open(indexId, AccessShareLock);
397  else
398  irel = NULL;
399 
400  sysscan = (SysScanDesc) palloc(sizeof(SysScanDescData));
401 
402  sysscan->heap_rel = heapRelation;
403  sysscan->irel = irel;
404  sysscan->slot = table_slot_create(heapRelation, NULL);
405 
406  if (snapshot == NULL)
407  {
408  Oid relid = RelationGetRelid(heapRelation);
409 
410  snapshot = RegisterSnapshot(GetCatalogSnapshot(relid));
411  sysscan->snapshot = snapshot;
412  }
413  else
414  {
415  /* Caller is responsible for any snapshot. */
416  sysscan->snapshot = NULL;
417  }
418 
419  if (irel)
420  {
421  int i;
422 
423  /* Change attribute numbers to be index column numbers. */
424  for (i = 0; i < nkeys; i++)
425  {
426  int j;
427 
428  for (j = 0; j < IndexRelationGetNumberOfAttributes(irel); j++)
429  {
430  if (key[i].sk_attno == irel->rd_index->indkey.values[j])
431  {
432  key[i].sk_attno = j + 1;
433  break;
434  }
435  }
437  elog(ERROR, "column is not in index");
438  }
439 
440  sysscan->iscan = index_beginscan(heapRelation, irel,
441  snapshot, nkeys, 0);
442  index_rescan(sysscan->iscan, key, nkeys, NULL, 0);
443  sysscan->scan = NULL;
444  }
445  else
446  {
447  /*
448  * We disallow synchronized scans when forced to use a heapscan on a
449  * catalog. In most cases the desired rows are near the front, so
450  * that the unpredictable start point of a syncscan is a serious
451  * disadvantage; and there are no compensating advantages, because
452  * it's unlikely that such scans will occur in parallel.
453  */
454  sysscan->scan = table_beginscan_strat(heapRelation, snapshot,
455  nkeys, key,
456  true, false);
457  sysscan->iscan = NULL;
458  }
459 
460  /*
461  * If CheckXidAlive is set then set a flag to indicate that system table
462  * scan is in-progress. See detailed comments in xact.c where these
463  * variables are declared.
464  */
466  bsysscan = true;
467 
468  return sysscan;
469 }
#define elog(elevel,...)
Definition: elog.h:224
struct SysScanDescData * SysScanDesc
Definition: genam.h:91
bool ReindexIsProcessingIndex(Oid indexOid)
Definition: index.c:4073
IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, int norderbys)
Definition: indexam.c:256
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:133
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:352
int j
Definition: isn.c:74
#define AccessShareLock
Definition: lockdefs.h:36
bool IgnoreSystemIndexes
Definition: miscinit.c:80
#define IndexRelationGetNumberOfAttributes(relation)
Definition: rel.h:517
Snapshot GetCatalogSnapshot(Oid relid)
Definition: snapmgr.c:352
Snapshot RegisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:794
Relation irel
Definition: relscan.h:184
Relation heap_rel
Definition: relscan.h:183
struct SnapshotData * snapshot
Definition: relscan.h:187
struct IndexScanDescData * iscan
Definition: relscan.h:186
struct TupleTableSlot * slot
Definition: relscan.h:188
struct TableScanDescData * scan
Definition: relscan.h:185
TupleTableSlot * table_slot_create(Relation relation, List **reglist)
Definition: tableam.c:91
static TableScanDesc table_beginscan_strat(Relation rel, Snapshot snapshot, int nkeys, struct ScanKeyData *key, bool allow_strat, bool allow_sync)
Definition: tableam.h:932
bool bsysscan
Definition: xact.c:98

References AccessShareLock, bsysscan, CheckXidAlive, elog, ERROR, GetCatalogSnapshot(), SysScanDescData::heap_rel, i, IgnoreSystemIndexes, index_beginscan(), index_open(), index_rescan(), IndexRelationGetNumberOfAttributes, SysScanDescData::irel, SysScanDescData::iscan, j, sort-test::key, palloc(), RelationData::rd_index, RegisterSnapshot(), ReindexIsProcessingIndex(), RelationGetRelid, SysScanDescData::scan, SysScanDescData::slot, SysScanDescData::snapshot, table_beginscan_strat(), table_slot_create(), and TransactionIdIsValid.

Referenced by AfterTriggerSetState(), AlterConstraintNamespaces(), AlterDatabase(), AlterDatabaseOwner(), AlterDatabaseRefreshColl(), AlterDomainDropConstraint(), AlterDomainValidateConstraint(), AlterExtensionNamespace(), AlterPolicy(), AlterSeqNamespaces(), AlterSetting(), AlterTypeRecurse(), ApplyExtensionUpdates(), ApplySetting(), ATExecAddOf(), ATExecAlterColumnType(), ATExecAlterConstraint(), ATExecAlterConstrRecurse(), ATExecAttachPartition(), ATExecDropConstraint(), ATExecValidateConstraint(), ATPrepChangePersistence(), AttrDefaultFetch(), change_owner_fix_column_acls(), change_owner_recurse_to_sequences(), changeDependenciesOf(), changeDependenciesOn(), changeDependencyFor(), CheckConstraintFetch(), checkSharedDependencies(), ChooseConstraintName(), CloneFkReferenced(), CloneRowTriggersToPartition(), ConstraintNameExists(), ConstraintNameIsUsed(), CopyStatistics(), copyTemplateDependencies(), CountDBSubscriptions(), CreateComments(), CreateInheritance(), CreatePolicy(), CreateSharedComments(), CreateTriggerFiringOn(), DefineOpClass(), DefineTSConfiguration(), DeleteAttributeTuples(), DeleteComments(), deleteDependencyRecordsFor(), deleteDependencyRecordsForClass(), deleteDependencyRecordsForSpecific(), DeleteInheritsTuple(), DeleteInitPrivs(), deleteOneObject(), DeleteSecurityLabel(), DeleteSharedComments(), DeleteSharedSecurityLabel(), DeleteSystemAttributeTuples(), drop_parent_dependency(), DropClonedTriggersFromPartition(), DropConfigurationMapping(), dropDatabaseDependencies(), DropObjectById(), DropRole(), EnableDisableTrigger(), EnumValuesDelete(), EventTriggerOnLogin(), exec_object_restorecon(), ExecAlterExtensionStmt(), ExecGrant_Largeobject(), extension_config_remove(), fetch_statentries_for_relation(), find_composite_type_dependencies(), find_inheritance_children_extended(), findDependentObjects(), findDomainNotNullConstraint(), get_catalog_object_by_oid(), get_database_oid(), get_db_info(), get_domain_constraint_oid(), get_extension_name(), get_extension_oid(), get_extension_schema(), get_index_constraint(), get_index_ref_constraints(), get_partition_parent_worker(), get_pkey_attnames(), get_primary_key_attnos(), get_relation_constraint_attnos(), get_relation_constraint_oid(), get_relation_idx_constraint_oid(), get_relation_policy_oid(), get_rels_with_domain(), get_trigger_oid(), GetAllTablesPublications(), GetAttrDefaultColumnAddress(), GetAttrDefaultOid(), getAutoExtensionsOfObject(), GetComment(), GetDatabaseTuple(), GetDatabaseTupleByOid(), GetDefaultOpClass(), getExtensionOfObject(), GetForeignKeyActionTriggers(), GetForeignKeyCheckTriggers(), GetNewOidWithIndex(), getObjectDescription(), getObjectIdentityParts(), getOwnedSequences_internal(), GetParentedForeignKeyRefs(), GetPublicationRelations(), GetPublicationSchemas(), GetSecurityLabel(), GetSharedSecurityLabel(), GetSubscriptionRelations(), has_superclass(), HasSubscriptionRelations(), heap_truncate_find_FKs(), index_concurrently_swap(), IndexSetParentIndex(), is_schema_publication(), LargeObjectDrop(), LargeObjectExists(), load_domaintype_info(), load_enum_cache_data(), LookupOpclassInfo(), makeConfigurationDependencies(), MakeConfigurationMapping(), MarkInheritDetached(), MergeConstraintsIntoExisting(), MergeWithExistingConstraint(), movedb(), myLargeObjectExists(), object_ownercheck(), PartitionHasPendingDetach(), pg_extension_config_dump(), pg_get_constraintdef_worker(), pg_get_serial_sequence(), pg_get_triggerdef_worker(), pg_largeobject_aclmask_snapshot(), RangeDelete(), recordExtensionInitPrivWorker(), recordExtObjInitPriv(), relation_has_policies(), RelationBuildPartitionDesc(), RelationBuildRowSecurity(), RelationBuildRuleLock(), RelationBuildTriggers(), RelationBuildTupleDesc(), RelationGetExclusionInfo(), RelationGetFKeyList(), RelationGetIndexList(), RelationGetStatExtList(), RelationRemoveInheritance(), RelidByRelfilenumber(), RememberAllDependentForRebuilding(), RemoveAttrDefault(), RemoveAttrDefaultById(), RemoveExtensionById(), RemoveInheritance(), RemovePolicyById(), RemoveRewriteRuleById(), RemoveRoleFromInitPriv(), RemoveRoleFromObjectACL(), RemoveRoleFromObjectPolicy(), RemoveStatistics(), RemoveTriggerById(), RemoveTSConfigurationById(), rename_policy(), renametrig(), renametrig_internal(), renametrig_partition(), ReplaceRoleInInitPriv(), replorigin_create(), ScanPgRelation(), SearchCatCacheList(), SearchCatCacheMiss(), sepgsql_attribute_post_create(), sepgsql_database_post_create(), sepgsql_proc_post_create(), sepgsql_proc_setattr(), sepgsql_relation_post_create(), sepgsql_relation_setattr(), sepgsql_relation_setattr_extra(), sepgsql_schema_post_create(), sequenceIsOwned(), SetSecurityLabel(), SetSharedSecurityLabel(), shdepChangeDep(), shdepDropDependency(), shdepDropOwned(), shdepReassignOwned(), toastrel_valueid_exists(), TriggerSetParentTrigger(), tryAttachPartitionForeignKey(), typeInheritsFrom(), vac_update_datfrozenxid(), and validatePartitionedIndex().

◆ systable_beginscan_ordered()

SysScanDesc systable_beginscan_ordered ( Relation  heapRelation,
Relation  indexRelation,
Snapshot  snapshot,
int  nkeys,
ScanKey  key 
)

Definition at line 643 of file genam.c.

647 {
648  SysScanDesc sysscan;
649  int i;
650 
651  /* REINDEX can probably be a hard error here ... */
652  if (ReindexIsProcessingIndex(RelationGetRelid(indexRelation)))
653  ereport(ERROR,
654  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
655  errmsg("cannot access index \"%s\" while it is being reindexed",
656  RelationGetRelationName(indexRelation))));
657  /* ... but we only throw a warning about violating IgnoreSystemIndexes */
659  elog(WARNING, "using index \"%s\" despite IgnoreSystemIndexes",
660  RelationGetRelationName(indexRelation));
661 
662  sysscan = (SysScanDesc) palloc(sizeof(SysScanDescData));
663 
664  sysscan->heap_rel = heapRelation;
665  sysscan->irel = indexRelation;
666  sysscan->slot = table_slot_create(heapRelation, NULL);
667 
668  if (snapshot == NULL)
669  {
670  Oid relid = RelationGetRelid(heapRelation);
671 
672  snapshot = RegisterSnapshot(GetCatalogSnapshot(relid));
673  sysscan->snapshot = snapshot;
674  }
675  else
676  {
677  /* Caller is responsible for any snapshot. */
678  sysscan->snapshot = NULL;
679  }
680 
681  /* Change attribute numbers to be index column numbers. */
682  for (i = 0; i < nkeys; i++)
683  {
684  int j;
685 
686  for (j = 0; j < IndexRelationGetNumberOfAttributes(indexRelation); j++)
687  {
688  if (key[i].sk_attno == indexRelation->rd_index->indkey.values[j])
689  {
690  key[i].sk_attno = j + 1;
691  break;
692  }
693  }
694  if (j == IndexRelationGetNumberOfAttributes(indexRelation))
695  elog(ERROR, "column is not in index");
696  }
697 
698  sysscan->iscan = index_beginscan(heapRelation, indexRelation,
699  snapshot, nkeys, 0);
700  index_rescan(sysscan->iscan, key, nkeys, NULL, 0);
701  sysscan->scan = NULL;
702 
703  return sysscan;
704 }
#define WARNING
Definition: elog.h:36
#define RelationGetRelationName(relation)
Definition: rel.h:539

References elog, ereport, errcode(), errmsg(), ERROR, GetCatalogSnapshot(), SysScanDescData::heap_rel, i, IgnoreSystemIndexes, index_beginscan(), index_rescan(), IndexRelationGetNumberOfAttributes, SysScanDescData::irel, SysScanDescData::iscan, j, sort-test::key, palloc(), RelationData::rd_index, RegisterSnapshot(), ReindexIsProcessingIndex(), RelationGetRelationName, RelationGetRelid, SysScanDescData::scan, SysScanDescData::slot, SysScanDescData::snapshot, table_slot_create(), and WARNING.

Referenced by BuildEventTriggerCache(), check_toasted_attribute(), enum_endpoint(), enum_range_internal(), heap_fetch_toast_slice(), inv_getsize(), inv_read(), inv_truncate(), inv_write(), lookup_ts_config_cache(), and toast_delete_datum().

◆ systable_endscan()

void systable_endscan ( SysScanDesc  sysscan)

Definition at line 596 of file genam.c.

597 {
598  if (sysscan->slot)
599  {
601  sysscan->slot = NULL;
602  }
603 
604  if (sysscan->irel)
605  {
606  index_endscan(sysscan->iscan);
607  index_close(sysscan->irel, AccessShareLock);
608  }
609  else
610  table_endscan(sysscan->scan);
611 
612  if (sysscan->snapshot)
613  UnregisterSnapshot(sysscan->snapshot);
614 
615  /*
616  * Reset the bsysscan flag at the end of the systable scan. See detailed
617  * comments in xact.c where these variables are declared.
618  */
620  bsysscan = false;
621 
622  pfree(sysscan);
623 }
void ExecDropSingleTupleTableSlot(TupleTableSlot *slot)
Definition: execTuples.c:1341
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:177
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:378
void UnregisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:836
static void table_endscan(TableScanDesc scan)
Definition: tableam.h:1019

References AccessShareLock, bsysscan, CheckXidAlive, ExecDropSingleTupleTableSlot(), index_close(), index_endscan(), SysScanDescData::irel, SysScanDescData::iscan, pfree(), SysScanDescData::scan, SysScanDescData::slot, SysScanDescData::snapshot, table_endscan(), TransactionIdIsValid, and UnregisterSnapshot().

Referenced by AfterTriggerSetState(), AlterConstraintNamespaces(), AlterDatabase(), AlterDatabaseOwner(), AlterDatabaseRefreshColl(), AlterDomainDropConstraint(), AlterDomainValidateConstraint(), AlterExtensionNamespace(), AlterPolicy(), AlterSeqNamespaces(), AlterSetting(), AlterTypeRecurse(), ApplyExtensionUpdates(), ApplySetting(), ATExecAddOf(), ATExecAlterColumnType(), ATExecAlterConstraint(), ATExecAlterConstrRecurse(), ATExecAttachPartition(), ATExecDropConstraint(), ATExecValidateConstraint(), ATPrepChangePersistence(), AttrDefaultFetch(), change_owner_fix_column_acls(), change_owner_recurse_to_sequences(), changeDependenciesOf(), changeDependenciesOn(), changeDependencyFor(), CheckConstraintFetch(), checkSharedDependencies(), ChooseConstraintName(), CloneFkReferenced(), CloneRowTriggersToPartition(), ConstraintNameExists(), ConstraintNameIsUsed(), CopyStatistics(), copyTemplateDependencies(), CountDBSubscriptions(), CreateComments(), CreateInheritance(), CreatePolicy(), CreateSharedComments(), CreateTriggerFiringOn(), DefineOpClass(), DefineTSConfiguration(), DeleteAttributeTuples(), DeleteComments(), deleteDependencyRecordsFor(), deleteDependencyRecordsForClass(), deleteDependencyRecordsForSpecific(), DeleteInheritsTuple(), DeleteInitPrivs(), deleteOneObject(), DeleteSecurityLabel(), DeleteSharedComments(), DeleteSharedSecurityLabel(), DeleteSystemAttributeTuples(), drop_parent_dependency(), DropClonedTriggersFromPartition(), DropConfigurationMapping(), dropDatabaseDependencies(), DropObjectById(), DropRole(), EnableDisableTrigger(), EnumValuesDelete(), EventTriggerOnLogin(), exec_object_restorecon(), ExecAlterExtensionStmt(), ExecGrant_Largeobject(), extension_config_remove(), fetch_statentries_for_relation(), find_composite_type_dependencies(), find_inheritance_children_extended(), findDependentObjects(), findDomainNotNullConstraint(), get_catalog_object_by_oid(), get_database_oid(), get_db_info(), get_domain_constraint_oid(), get_extension_name(), get_extension_oid(), get_extension_schema(), get_index_constraint(), get_index_ref_constraints(), get_partition_parent_worker(), get_pkey_attnames(), get_primary_key_attnos(), get_relation_constraint_attnos(), get_relation_constraint_oid(), get_relation_idx_constraint_oid(), get_relation_policy_oid(), get_rels_with_domain(), get_trigger_oid(), GetAllTablesPublications(), GetAttrDefaultColumnAddress(), GetAttrDefaultOid(), getAutoExtensionsOfObject(), GetComment(), GetDatabaseTuple(), GetDatabaseTupleByOid(), GetDefaultOpClass(), getExtensionOfObject(), GetForeignKeyActionTriggers(), GetForeignKeyCheckTriggers(), GetNewOidWithIndex(), getObjectDescription(), getObjectIdentityParts(), getOwnedSequences_internal(), GetParentedForeignKeyRefs(), GetPublicationRelations(), GetPublicationSchemas(), GetSecurityLabel(), GetSharedSecurityLabel(), GetSubscriptionRelations(), has_superclass(), HasSubscriptionRelations(), heap_truncate_find_FKs(), index_concurrently_swap(), IndexSetParentIndex(), is_schema_publication(), LargeObjectDrop(), LargeObjectExists(), load_domaintype_info(), load_enum_cache_data(), LookupOpclassInfo(), makeConfigurationDependencies(), MakeConfigurationMapping(), MarkInheritDetached(), MergeConstraintsIntoExisting(), MergeWithExistingConstraint(), movedb(), myLargeObjectExists(), object_ownercheck(), PartitionHasPendingDetach(), pg_extension_config_dump(), pg_get_constraintdef_worker(), pg_get_serial_sequence(), pg_get_triggerdef_worker(), pg_largeobject_aclmask_snapshot(), RangeDelete(), recordExtensionInitPrivWorker(), recordExtObjInitPriv(), relation_has_policies(), RelationBuildPartitionDesc(), RelationBuildRowSecurity(), RelationBuildRuleLock(), RelationBuildTriggers(), RelationBuildTupleDesc(), RelationGetExclusionInfo(), RelationGetFKeyList(), RelationGetIndexList(), RelationGetStatExtList(), RelationRemoveInheritance(), RelidByRelfilenumber(), RememberAllDependentForRebuilding(), RemoveAttrDefault(), RemoveAttrDefaultById(), RemoveExtensionById(), RemoveInheritance(), RemovePolicyById(), RemoveRewriteRuleById(), RemoveRoleFromInitPriv(), RemoveRoleFromObjectACL(), RemoveRoleFromObjectPolicy(), RemoveStatistics(), RemoveTriggerById(), RemoveTSConfigurationById(), rename_policy(), renametrig(), renametrig_internal(), renametrig_partition(), ReplaceRoleInInitPriv(), replorigin_create(), ScanPgRelation(), SearchCatCacheList(), SearchCatCacheMiss(), sepgsql_attribute_post_create(), sepgsql_database_post_create(), sepgsql_proc_post_create(), sepgsql_proc_setattr(), sepgsql_relation_post_create(), sepgsql_relation_setattr(), sepgsql_relation_setattr_extra(), sepgsql_schema_post_create(), sequenceIsOwned(), SetSecurityLabel(), SetSharedSecurityLabel(), shdepChangeDep(), shdepDropDependency(), shdepDropOwned(), shdepReassignOwned(), toastrel_valueid_exists(), TriggerSetParentTrigger(), tryAttachPartitionForeignKey(), typeInheritsFrom(), vac_update_datfrozenxid(), and validatePartitionedIndex().

◆ systable_endscan_ordered()

void systable_endscan_ordered ( SysScanDesc  sysscan)

◆ systable_getnext()

HeapTuple systable_getnext ( SysScanDesc  sysscan)

Definition at line 503 of file genam.c.

504 {
505  HeapTuple htup = NULL;
506 
507  if (sysscan->irel)
508  {
509  if (index_getnext_slot(sysscan->iscan, ForwardScanDirection, sysscan->slot))
510  {
511  bool shouldFree;
512 
513  htup = ExecFetchSlotHeapTuple(sysscan->slot, false, &shouldFree);
514  Assert(!shouldFree);
515 
516  /*
517  * We currently don't need to support lossy index operators for
518  * any system catalog scan. It could be done here, using the scan
519  * keys to drive the operator calls, if we arranged to save the
520  * heap attnums during systable_beginscan(); this is practical
521  * because we still wouldn't need to support indexes on
522  * expressions.
523  */
524  if (sysscan->iscan->xs_recheck)
525  elog(ERROR, "system catalog scans with lossy index conditions are not implemented");
526  }
527  }
528  else
529  {
530  if (table_scan_getnextslot(sysscan->scan, ForwardScanDirection, sysscan->slot))
531  {
532  bool shouldFree;
533 
534  htup = ExecFetchSlotHeapTuple(sysscan->slot, false, &shouldFree);
535  Assert(!shouldFree);
536  }
537  }
538 
539  /*
540  * Handle the concurrent abort while fetching the catalog tuple during
541  * logical streaming of a transaction.
542  */
544 
545  return htup;
546 }
HeapTuple ExecFetchSlotHeapTuple(TupleTableSlot *slot, bool materialize, bool *shouldFree)
Definition: execTuples.c:1731
static void HandleConcurrentAbort()
Definition: genam.c:480
bool index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
Definition: indexam.c:673
@ ForwardScanDirection
Definition: sdir.h:28
static bool table_scan_getnextslot(TableScanDesc sscan, ScanDirection direction, TupleTableSlot *slot)
Definition: tableam.h:1055

References Assert, elog, ERROR, ExecFetchSlotHeapTuple(), ForwardScanDirection, HandleConcurrentAbort(), index_getnext_slot(), SysScanDescData::irel, SysScanDescData::iscan, SysScanDescData::scan, SysScanDescData::slot, table_scan_getnextslot(), and IndexScanDescData::xs_recheck.

Referenced by AfterTriggerSetState(), AlterConstraintNamespaces(), AlterDatabase(), AlterDatabaseOwner(), AlterDatabaseRefreshColl(), AlterDomainDropConstraint(), AlterDomainValidateConstraint(), AlterExtensionNamespace(), AlterPolicy(), AlterSeqNamespaces(), AlterSetting(), AlterTypeRecurse(), ApplyExtensionUpdates(), ApplySetting(), ATExecAddOf(), ATExecAlterColumnType(), ATExecAlterConstraint(), ATExecAlterConstrRecurse(), ATExecAttachPartition(), ATExecDropConstraint(), ATExecValidateConstraint(), ATPrepChangePersistence(), AttrDefaultFetch(), change_owner_fix_column_acls(), change_owner_recurse_to_sequences(), changeDependenciesOf(), changeDependenciesOn(), changeDependencyFor(), CheckConstraintFetch(), checkSharedDependencies(), ChooseConstraintName(), CloneFkReferenced(), CloneRowTriggersToPartition(), ConstraintNameExists(), ConstraintNameIsUsed(), CopyStatistics(), copyTemplateDependencies(), CountDBSubscriptions(), CreateComments(), CreateInheritance(), CreatePolicy(), CreateSharedComments(), CreateTriggerFiringOn(), DefineOpClass(), DefineTSConfiguration(), DeleteAttributeTuples(), DeleteComments(), deleteDependencyRecordsFor(), deleteDependencyRecordsForClass(), deleteDependencyRecordsForSpecific(), DeleteInheritsTuple(), DeleteInitPrivs(), deleteOneObject(), DeleteSecurityLabel(), DeleteSharedComments(), DeleteSharedSecurityLabel(), DeleteSystemAttributeTuples(), drop_parent_dependency(), DropClonedTriggersFromPartition(), DropConfigurationMapping(), dropDatabaseDependencies(), DropObjectById(), DropRole(), EnableDisableTrigger(), EnumValuesDelete(), EventTriggerOnLogin(), exec_object_restorecon(), ExecAlterExtensionStmt(), ExecGrant_Largeobject(), extension_config_remove(), fetch_statentries_for_relation(), find_composite_type_dependencies(), find_inheritance_children_extended(), findDependentObjects(), findDomainNotNullConstraint(), get_catalog_object_by_oid(), get_database_oid(), get_db_info(), get_domain_constraint_oid(), get_extension_name(), get_extension_oid(), get_extension_schema(), get_index_constraint(), get_index_ref_constraints(), get_partition_parent_worker(), get_pkey_attnames(), get_primary_key_attnos(), get_relation_constraint_attnos(), get_relation_constraint_oid(), get_relation_idx_constraint_oid(), get_relation_policy_oid(), get_rels_with_domain(), get_trigger_oid(), GetAllTablesPublications(), GetAttrDefaultColumnAddress(), GetAttrDefaultOid(), getAutoExtensionsOfObject(), GetComment(), GetDatabaseTuple(), GetDatabaseTupleByOid(), GetDefaultOpClass(), getExtensionOfObject(), GetForeignKeyActionTriggers(), GetForeignKeyCheckTriggers(), GetNewOidWithIndex(), getObjectDescription(), getObjectIdentityParts(), getOwnedSequences_internal(), GetParentedForeignKeyRefs(), GetPublicationRelations(), GetPublicationSchemas(), GetSecurityLabel(), GetSharedSecurityLabel(), GetSubscriptionRelations(), has_superclass(), HasSubscriptionRelations(), heap_truncate_find_FKs(), index_concurrently_swap(), IndexSetParentIndex(), is_schema_publication(), LargeObjectDrop(), LargeObjectExists(), load_domaintype_info(), load_enum_cache_data(), LookupOpclassInfo(), makeConfigurationDependencies(), MakeConfigurationMapping(), MarkInheritDetached(), MergeConstraintsIntoExisting(), MergeWithExistingConstraint(), movedb(), myLargeObjectExists(), object_ownercheck(), PartitionHasPendingDetach(), pg_extension_config_dump(), pg_get_constraintdef_worker(), pg_get_serial_sequence(), pg_get_triggerdef_worker(), pg_largeobject_aclmask_snapshot(), RangeDelete(), recordExtensionInitPrivWorker(), recordExtObjInitPriv(), relation_has_policies(), RelationBuildPartitionDesc(), RelationBuildRowSecurity(), RelationBuildRuleLock(), RelationBuildTriggers(), RelationBuildTupleDesc(), RelationGetExclusionInfo(), RelationGetFKeyList(), RelationGetIndexList(), RelationGetStatExtList(), RelationRemoveInheritance(), RelidByRelfilenumber(), RememberAllDependentForRebuilding(), RemoveAttrDefault(), RemoveAttrDefaultById(), RemoveExtensionById(), RemoveInheritance(), RemovePolicyById(), RemoveRewriteRuleById(), RemoveRoleFromInitPriv(), RemoveRoleFromObjectACL(), RemoveRoleFromObjectPolicy(), RemoveStatistics(), RemoveTriggerById(), RemoveTSConfigurationById(), rename_policy(), renametrig(), renametrig_internal(), renametrig_partition(), ReplaceRoleInInitPriv(), replorigin_create(), ScanPgRelation(), SearchCatCacheList(), SearchCatCacheMiss(), sepgsql_attribute_post_create(), sepgsql_database_post_create(), sepgsql_proc_post_create(), sepgsql_proc_setattr(), sepgsql_relation_post_create(), sepgsql_relation_setattr(), sepgsql_relation_setattr_extra(), sepgsql_schema_post_create(), sequenceIsOwned(), SetSecurityLabel(), SetSharedSecurityLabel(), shdepChangeDep(), shdepDropDependency(), shdepDropOwned(), shdepReassignOwned(), toastrel_valueid_exists(), TriggerSetParentTrigger(), tryAttachPartitionForeignKey(), typeInheritsFrom(), vac_update_datfrozenxid(), and validatePartitionedIndex().

◆ systable_getnext_ordered()

HeapTuple systable_getnext_ordered ( SysScanDesc  sysscan,
ScanDirection  direction 
)

Definition at line 710 of file genam.c.

711 {
712  HeapTuple htup = NULL;
713 
714  Assert(sysscan->irel);
715  if (index_getnext_slot(sysscan->iscan, direction, sysscan->slot))
716  htup = ExecFetchSlotHeapTuple(sysscan->slot, false, NULL);
717 
718  /* See notes in systable_getnext */
719  if (htup && sysscan->iscan->xs_recheck)
720  elog(ERROR, "system catalog scans with lossy index conditions are not implemented");
721 
722  /*
723  * Handle the concurrent abort while fetching the catalog tuple during
724  * logical streaming of a transaction.
725  */
727 
728  return htup;
729 }

References Assert, elog, ERROR, ExecFetchSlotHeapTuple(), HandleConcurrentAbort(), index_getnext_slot(), SysScanDescData::irel, SysScanDescData::iscan, SysScanDescData::slot, and IndexScanDescData::xs_recheck.

Referenced by BuildEventTriggerCache(), check_toasted_attribute(), enum_endpoint(), enum_range_internal(), heap_fetch_toast_slice(), inv_getsize(), inv_read(), inv_truncate(), inv_write(), lookup_ts_config_cache(), and toast_delete_datum().

◆ systable_recheck_tuple()

bool systable_recheck_tuple ( SysScanDesc  sysscan,
HeapTuple  tup 
)

Definition at line 562 of file genam.c.

563 {
564  Snapshot freshsnap;
565  bool result;
566 
567  Assert(tup == ExecFetchSlotHeapTuple(sysscan->slot, false, NULL));
568 
569  /*
570  * Trust that table_tuple_satisfies_snapshot() and its subsidiaries
571  * (commonly LockBuffer() and HeapTupleSatisfiesMVCC()) do not themselves
572  * acquire snapshots, so we need not register the snapshot. Those
573  * facilities are too low-level to have any business scanning tables.
574  */
575  freshsnap = GetCatalogSnapshot(RelationGetRelid(sysscan->heap_rel));
576 
577  result = table_tuple_satisfies_snapshot(sysscan->heap_rel,
578  sysscan->slot,
579  freshsnap);
580 
581  /*
582  * Handle the concurrent abort while fetching the catalog tuple during
583  * logical streaming of a transaction.
584  */
586 
587  return result;
588 }
static bool table_tuple_satisfies_snapshot(Relation rel, TupleTableSlot *slot, Snapshot snapshot)
Definition: tableam.h:1335

References Assert, ExecFetchSlotHeapTuple(), GetCatalogSnapshot(), HandleConcurrentAbort(), SysScanDescData::heap_rel, RelationGetRelid, SysScanDescData::slot, and table_tuple_satisfies_snapshot().

Referenced by CatalogCacheCreateEntry(), findDependentObjects(), and shdepDropOwned().