PostgreSQL Source Code  git master
genam.c File Reference
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.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/builtins.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/rls.h"
#include "utils/ruleutils.h"
#include "utils/snapmgr.h"
#include "utils/syscache.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, Datum *values, 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,
Datum values,
bool isnull 
)

Definition at line 177 of file genam.c.

References ACL_SELECT, ACLCHECK_OK, appendStringInfo(), appendStringInfoChar(), appendStringInfoString(), Assert, attnum, buf, check_enable_rls(), StringInfoData::data, 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, and val.

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

179 {
181  Form_pg_index idxrec;
182  int indnkeyatts;
183  int i;
184  int keyno;
185  Oid indexrelid = RelationGetRelid(indexRelation);
186  Oid indrelid;
187  AclResult aclresult;
188 
189  indnkeyatts = IndexRelationGetNumberOfKeyAttributes(indexRelation);
190 
191  /*
192  * Check permissions- if the user does not have access to view all of the
193  * key columns then return NULL to avoid leaking data.
194  *
195  * First check if RLS is enabled for the relation. If so, return NULL to
196  * avoid leaking data.
197  *
198  * Next we need to check table-level SELECT access and then, if there is
199  * no access there, check column-level permissions.
200  */
201  idxrec = indexRelation->rd_index;
202  indrelid = idxrec->indrelid;
203  Assert(indexrelid == idxrec->indexrelid);
204 
205  /* RLS check- if RLS is enabled then we don't return anything. */
206  if (check_enable_rls(indrelid, InvalidOid, true) == RLS_ENABLED)
207  return NULL;
208 
209  /* Table-level SELECT is enough, if the user has it */
210  aclresult = pg_class_aclcheck(indrelid, GetUserId(), ACL_SELECT);
211  if (aclresult != ACLCHECK_OK)
212  {
213  /*
214  * No table-level access, so step through the columns in the index and
215  * make sure the user has SELECT rights on all of them.
216  */
217  for (keyno = 0; keyno < indnkeyatts; keyno++)
218  {
219  AttrNumber attnum = idxrec->indkey.values[keyno];
220 
221  /*
222  * Note that if attnum == InvalidAttrNumber, then this is an index
223  * based on an expression and we return no detail rather than try
224  * to figure out what column(s) the expression includes and if the
225  * user has SELECT rights on them.
226  */
227  if (attnum == InvalidAttrNumber ||
228  pg_attribute_aclcheck(indrelid, attnum, GetUserId(),
230  {
231  /* No access, so clean up and return */
232  return NULL;
233  }
234  }
235  }
236 
237  initStringInfo(&buf);
238  appendStringInfo(&buf, "(%s)=(",
239  pg_get_indexdef_columns(indexrelid, true));
240 
241  for (i = 0; i < indnkeyatts; i++)
242  {
243  char *val;
244 
245  if (isnull[i])
246  val = "null";
247  else
248  {
249  Oid foutoid;
250  bool typisvarlena;
251 
252  /*
253  * The provided data is not necessarily of the type stored in the
254  * index; rather it is of the index opclass's input type. So look
255  * at rd_opcintype not the index tupdesc.
256  *
257  * Note: this is a bit shaky for opclasses that have pseudotype
258  * input types such as ANYARRAY or RECORD. Currently, the
259  * typoutput functions associated with the pseudotypes will work
260  * okay, but we might have to try harder in future.
261  */
262  getTypeOutputInfo(indexRelation->rd_opcintype[i],
263  &foutoid, &typisvarlena);
264  val = OidOutputFunctionCall(foutoid, values[i]);
265  }
266 
267  if (i > 0)
268  appendStringInfoString(&buf, ", ");
269  appendStringInfoString(&buf, val);
270  }
271 
272  appendStringInfoChar(&buf, ')');
273 
274  return buf.data;
275 }
void getTypeOutputInfo(Oid type, Oid *typOutput, bool *typIsVarlena)
Definition: lsyscache.c:2784
AclResult pg_attribute_aclcheck(Oid table_oid, AttrNumber attnum, Oid roleid, AclMode mode)
Definition: aclchk.c:4449
Oid GetUserId(void)
Definition: miscinit.c:476
char * pg_get_indexdef_columns(Oid indexrelid, bool pretty)
Definition: ruleutils.c:1169
unsigned int Oid
Definition: postgres_ext.h:31
Form_pg_index rd_index
Definition: rel.h:174
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:91
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:176
static char * buf
Definition: pg_test_fsync.c:68
#define IndexRelationGetNumberOfKeyAttributes(relation)
Definition: rel.h:475
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:188
void initStringInfo(StringInfo str)
Definition: stringinfo.c:59
FormData_pg_index * Form_pg_index
Definition: pg_index.h:68
AclResult
Definition: acl.h:177
#define ACL_SELECT
Definition: parsenodes.h:75
#define InvalidOid
Definition: postgres_ext.h:36
int16 attnum
Definition: pg_attribute.h:79
int check_enable_rls(Oid relid, Oid checkAsUser, bool noError)
Definition: rls.c:52
#define Assert(condition)
Definition: c.h:745
#define InvalidAttrNumber
Definition: attnum.h:23
AclResult pg_class_aclcheck(Oid table_oid, Oid roleid, AclMode mode)
Definition: aclchk.c:4563
static Datum values[MAXATTR]
Definition: bootstrap.c:165
char * OidOutputFunctionCall(Oid functionId, Datum val)
Definition: fmgr.c:1657
int i
Oid * rd_opcintype
Definition: rel.h:190
int16 AttrNumber
Definition: attnum.h:21
#define RelationGetRelid(relation)
Definition: rel.h:456
long val
Definition: informix.c:664

◆ HandleConcurrentAbort()

static void HandleConcurrentAbort ( )
inlinestatic

Definition at line 453 of file genam.c.

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

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

454 {
458  ereport(ERROR,
459  (errcode(ERRCODE_TRANSACTION_ROLLBACK),
460  errmsg("transaction aborted during system catalog scan")));
461 }
bool TransactionIdIsInProgress(TransactionId xid)
Definition: procarray.c:1305
int errcode(int sqlerrcode)
Definition: elog.c:610
bool TransactionIdDidCommit(TransactionId transactionId)
Definition: transam.c:125
#define ERROR
Definition: elog.h:43
TransactionId CheckXidAlive
Definition: xact.c:95
#define ereport(elevel,...)
Definition: elog.h:144
int errmsg(const char *fmt,...)
Definition: elog.c:824
#define TransactionIdIsValid(xid)
Definition: transam.h:41

◆ 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 286 of file genam.c.

References BufferGetPage, i, InvalidTransactionId, ItemPointerCopy, PageGetItem, PageGetItemId, palloc(), pfree(), IndexTupleData::t_tid, and table_compute_xid_horizon_for_tuples().

Referenced by _hash_vacuum_one_page(), and gistprunepage().

291 {
292  ItemPointerData *ttids =
293  (ItemPointerData *) palloc(sizeof(ItemPointerData) * nitems);
294  TransactionId latestRemovedXid = InvalidTransactionId;
295  Page ipage = BufferGetPage(ibuf);
296  IndexTuple itup;
297 
298  /* identify what the index tuples about to be deleted point to */
299  for (int i = 0; i < nitems; i++)
300  {
301  ItemId iitemid;
302 
303  iitemid = PageGetItemId(ipage, itemnos[i]);
304  itup = (IndexTuple) PageGetItem(ipage, iitemid);
305 
306  ItemPointerCopy(&itup->t_tid, &ttids[i]);
307  }
308 
309  /* determine the actual xid horizon */
310  latestRemovedXid =
311  table_compute_xid_horizon_for_tuples(hrel, ttids, nitems);
312 
313  pfree(ttids);
314 
315  return latestRemovedXid;
316 }
uint32 TransactionId
Definition: c.h:520
ItemPointerData t_tid
Definition: itup.h:37
static TransactionId table_compute_xid_horizon_for_tuples(Relation rel, ItemPointerData *items, int nitems)
Definition: tableam.h:1130
void pfree(void *pointer)
Definition: mcxt.c:1057
IndexTupleData * IndexTuple
Definition: itup.h:53
#define InvalidTransactionId
Definition: transam.h:31
#define BufferGetPage(buffer)
Definition: bufmgr.h:169
#define PageGetItemId(page, offsetNumber)
Definition: bufpage.h:235
void * palloc(Size size)
Definition: mcxt.c:950
int i
#define PageGetItem(page, itemId)
Definition: bufpage.h:340
Pointer Page
Definition: bufpage.h:78
#define ItemPointerCopy(fromPointer, toPointer)
Definition: itemptr.h:161

◆ IndexScanEnd()

void IndexScanEnd ( IndexScanDesc  scan)

Definition at line 145 of file genam.c.

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

Referenced by index_endscan().

146 {
147  if (scan->keyData != NULL)
148  pfree(scan->keyData);
149  if (scan->orderByData != NULL)
150  pfree(scan->orderByData);
151 
152  pfree(scan);
153 }
struct ScanKeyData * orderByData
Definition: relscan.h:120
void pfree(void *pointer)
Definition: mcxt.c:1057
struct ScanKeyData * keyData
Definition: relscan.h:119

◆ RelationGetIndexScan()

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

Definition at line 81 of file genam.c.

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().

82 {
83  IndexScanDesc scan;
84 
85  scan = (IndexScanDesc) palloc(sizeof(IndexScanDescData));
86 
87  scan->heapRelation = NULL; /* may be set later */
88  scan->xs_heapfetch = NULL;
89  scan->indexRelation = indexRelation;
90  scan->xs_snapshot = InvalidSnapshot; /* caller must initialize this */
91  scan->numberOfKeys = nkeys;
92  scan->numberOfOrderBys = norderbys;
93 
94  /*
95  * We allocate key workspace here, but it won't get filled until amrescan.
96  */
97  if (nkeys > 0)
98  scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * nkeys);
99  else
100  scan->keyData = NULL;
101  if (norderbys > 0)
102  scan->orderByData = (ScanKey) palloc(sizeof(ScanKeyData) * norderbys);
103  else
104  scan->orderByData = NULL;
105 
106  scan->xs_want_itup = false; /* may be set later */
107 
108  /*
109  * During recovery we ignore killed tuples and don't bother to kill them
110  * either. We do this because the xmin on the primary node could easily be
111  * later than the xmin on the standby node, so that what the primary
112  * thinks is killed is supposed to be visible on standby. So for correct
113  * MVCC for queries during recovery we must ignore these hints and check
114  * all tuples. Do *not* set ignore_killed_tuples to true when running in a
115  * transaction that was started during recovery. xactStartedInRecovery
116  * should not be altered by index AMs.
117  */
118  scan->kill_prior_tuple = false;
121 
122  scan->opaque = NULL;
123 
124  scan->xs_itup = NULL;
125  scan->xs_itupdesc = NULL;
126  scan->xs_hitup = NULL;
127  scan->xs_hitupdesc = NULL;
128 
129  return scan;
130 }
bool TransactionStartedDuringRecovery(void)
Definition: xact.c:970
struct ScanKeyData * orderByData
Definition: relscan.h:120
IndexTuple xs_itup
Definition: relscan.h:139
struct TupleDescData * xs_itupdesc
Definition: relscan.h:140
struct TupleDescData * xs_hitupdesc
Definition: relscan.h:142
struct SnapshotData * xs_snapshot
Definition: relscan.h:116
bool ignore_killed_tuples
Definition: relscan.h:126
Relation indexRelation
Definition: relscan.h:115
Relation heapRelation
Definition: relscan.h:114
bool xactStartedInRecovery
Definition: relscan.h:127
ScanKeyData * ScanKey
Definition: skey.h:75
#define InvalidSnapshot
Definition: snapshot.h:123
IndexFetchTableData * xs_heapfetch
Definition: relscan.h:147
struct ScanKeyData * keyData
Definition: relscan.h:119
void * palloc(Size size)
Definition: mcxt.c:950
HeapTuple xs_hitup
Definition: relscan.h:141
bool kill_prior_tuple
Definition: relscan.h:125
int numberOfOrderBys
Definition: relscan.h:118
struct IndexScanDescData * IndexScanDesc
Definition: genam.h:87

◆ systable_beginscan()

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

Definition at line 357 of file genam.c.

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

Referenced by AfterTriggerSetState(), AlterConstraintNamespaces(), AlterDatabase(), AlterDatabaseOwner(), AlterDomainDropConstraint(), AlterDomainValidateConstraint(), AlterExtensionNamespace(), AlterPolicy(), AlterSeqNamespaces(), AlterSetting(), AlterTypeRecurse(), ApplyExtensionUpdates(), ApplySetting(), ATExecAddOf(), ATExecAlterColumnType(), ATExecAlterConstraint(), ATExecAttachPartition(), ATExecDropConstraint(), ATExecDropExpression(), ATExecValidateConstraint(), ATPrepChangePersistence(), AttrDefaultFetch(), change_owner_fix_column_acls(), change_owner_recurse_to_sequences(), changeDependenciesOf(), changeDependenciesOn(), changeDependencyFor(), CheckConstraintFetch(), checkSharedDependencies(), ChooseConstraintName(), CloneFkReferenced(), CloneRowTriggersToPartition(), ConstraintNameExists(), ConstraintNameIsUsed(), copyTemplateDependencies(), CountDBSubscriptions(), CreateComments(), CreateInheritance(), CreatePolicy(), CreateSharedComments(), CreateTrigger(), DefineOpClass(), DefineTSConfiguration(), DeleteAttributeTuples(), DeleteComments(), deleteDependencyRecordsFor(), deleteDependencyRecordsForClass(), deleteDependencyRecordsForSpecific(), DeleteInheritsTuple(), DeleteInitPrivs(), deleteOneObject(), DeleteSecurityLabel(), DeleteSharedComments(), DeleteSharedSecurityLabel(), DeleteSystemAttributeTuples(), drop_parent_dependency(), DropClonedTriggersFromPartition(), DropConfigurationMapping(), dropDatabaseDependencies(), DropObjectById(), DropRole(), EnableDisableTrigger(), EnumValuesDelete(), exec_object_restorecon(), ExecAlterExtensionStmt(), ExecGrant_Largeobject(), extension_config_remove(), fetch_statentries_for_relation(), find_composite_type_dependencies(), find_inheritance_children(), findDependentObjects(), get_catalog_object_by_oid(), get_constraint_index(), 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_object_address_attrdef(), 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(), getAutoExtensionsOfObject(), GetComment(), GetDatabaseTuple(), GetDatabaseTupleByOid(), GetDefaultOpClass(), getExtensionOfObject(), GetNewOidWithIndex(), getObjectDescription(), getObjectIdentityParts(), getOwnedSequences_internal(), GetParentedForeignKeyRefs(), GetPublicationRelations(), GetSecurityLabel(), GetSharedSecurityLabel(), GetSubscriptionNotReadyRelations(), GetSubscriptionRelations(), has_superclass(), heap_truncate_find_FKs(), index_concurrently_swap(), IndexSetParentIndex(), isObjectPinned(), isSharedObjectPinned(), LargeObjectDrop(), LargeObjectExists(), load_domaintype_info(), load_enum_cache_data(), LookupOpclassInfo(), makeConfigurationDependencies(), MakeConfigurationMapping(), MergeConstraintsIntoExisting(), MergeWithExistingConstraint(), movedb(), myLargeObjectExists(), pg_extension_config_dump(), pg_extension_ownercheck(), pg_get_constraintdef_worker(), pg_get_serial_sequence(), pg_get_triggerdef_worker(), pg_largeobject_aclmask_snapshot(), pg_largeobject_ownercheck(), RangeDelete(), recordExtensionInitPrivWorker(), recordExtObjInitPriv(), relation_has_policies(), RelationBuildPartitionDesc(), RelationBuildRowSecurity(), RelationBuildRuleLock(), RelationBuildTriggers(), RelationBuildTupleDesc(), RelationGetExclusionInfo(), RelationGetFKeyList(), RelationGetIndexList(), RelationGetStatExtList(), RelationRemoveInheritance(), RelidByRelfilenode(), RemoveAttrDefault(), RemoveAttrDefaultById(), RemoveExtensionById(), RemoveInheritance(), RemovePolicyById(), RemoveRewriteRuleById(), RemoveRoleFromObjectACL(), RemoveRoleFromObjectPolicy(), RemoveStatistics(), RemoveTriggerById(), RemoveTSConfigurationById(), rename_policy(), renametrig(), 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(), tryAttachPartitionForeignKey(), typeInheritsFrom(), vac_update_datfrozenxid(), and validatePartitionedIndex().

362 {
363  SysScanDesc sysscan;
364  Relation irel;
365 
366  if (indexOK &&
368  !ReindexIsProcessingIndex(indexId))
369  irel = index_open(indexId, AccessShareLock);
370  else
371  irel = NULL;
372 
373  sysscan = (SysScanDesc) palloc(sizeof(SysScanDescData));
374 
375  sysscan->heap_rel = heapRelation;
376  sysscan->irel = irel;
377  sysscan->slot = table_slot_create(heapRelation, NULL);
378 
379  if (snapshot == NULL)
380  {
381  Oid relid = RelationGetRelid(heapRelation);
382 
383  snapshot = RegisterSnapshot(GetCatalogSnapshot(relid));
384  sysscan->snapshot = snapshot;
385  }
386  else
387  {
388  /* Caller is responsible for any snapshot. */
389  sysscan->snapshot = NULL;
390  }
391 
392  if (irel)
393  {
394  int i;
395 
396  /* Change attribute numbers to be index column numbers. */
397  for (i = 0; i < nkeys; i++)
398  {
399  int j;
400 
401  for (j = 0; j < IndexRelationGetNumberOfAttributes(irel); j++)
402  {
403  if (key[i].sk_attno == irel->rd_index->indkey.values[j])
404  {
405  key[i].sk_attno = j + 1;
406  break;
407  }
408  }
409  if (j == IndexRelationGetNumberOfAttributes(irel))
410  elog(ERROR, "column is not in index");
411  }
412 
413  sysscan->iscan = index_beginscan(heapRelation, irel,
414  snapshot, nkeys, 0);
415  index_rescan(sysscan->iscan, key, nkeys, NULL, 0);
416  sysscan->scan = NULL;
417  }
418  else
419  {
420  /*
421  * We disallow synchronized scans when forced to use a heapscan on a
422  * catalog. In most cases the desired rows are near the front, so
423  * that the unpredictable start point of a syncscan is a serious
424  * disadvantage; and there are no compensating advantages, because
425  * it's unlikely that such scans will occur in parallel.
426  */
427  sysscan->scan = table_beginscan_strat(heapRelation, snapshot,
428  nkeys, key,
429  true, false);
430  sysscan->iscan = NULL;
431  }
432 
433  /*
434  * If CheckXidAlive is set then set a flag to indicate that system table
435  * scan is in-progress. See detailed comments in xact.c where these
436  * variables are declared.
437  */
439  bsysscan = true;
440 
441  return sysscan;
442 }
TupleTableSlot * table_slot_create(Relation relation, List **reglist)
Definition: tableam.c:91
Relation irel
Definition: relscan.h:181
struct SysScanDescData * SysScanDesc
Definition: genam.h:88
Relation heap_rel
Definition: relscan.h:180
Snapshot RegisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:810
struct SnapshotData * snapshot
Definition: relscan.h:184
Snapshot GetCatalogSnapshot(Oid relid)
Definition: snapmgr.c:386
#define AccessShareLock
Definition: lockdefs.h:36
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:295
bool IgnoreSystemIndexes
Definition: miscinit.c:79
unsigned int Oid
Definition: postgres_ext.h:31
struct IndexScanDescData * iscan
Definition: relscan.h:183
struct TupleTableSlot * slot
Definition: relscan.h:185
static TableScanDesc table_beginscan_strat(Relation rel, Snapshot snapshot, int nkeys, struct ScanKeyData *key, bool allow_strat, bool allow_sync)
Definition: tableam.h:779
Form_pg_index rd_index
Definition: rel.h:174
#define ERROR
Definition: elog.h:43
struct TableScanDescData * scan
Definition: relscan.h:182
bool bsysscan
Definition: xact.c:96
#define IndexRelationGetNumberOfAttributes(relation)
Definition: rel.h:468
TransactionId CheckXidAlive
Definition: xact.c:95
void * palloc(Size size)
Definition: mcxt.c:950
#define elog(elevel,...)
Definition: elog.h:214
int i
#define TransactionIdIsValid(xid)
Definition: transam.h:41
bool ReindexIsProcessingIndex(Oid indexOid)
Definition: index.c:3845
#define RelationGetRelid(relation)
Definition: rel.h:456
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:132
AttrNumber sk_attno
Definition: skey.h:67
IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, int norderbys)
Definition: indexam.c:203

◆ systable_beginscan_ordered()

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

Definition at line 616 of file genam.c.

References elog, ERROR, GetCatalogSnapshot(), SysScanDescData::heap_rel, i, IgnoreSystemIndexes, index_beginscan(), index_rescan(), IndexRelationGetNumberOfAttributes, SysScanDescData::irel, SysScanDescData::iscan, palloc(), RelationData::rd_index, RegisterSnapshot(), ReindexIsProcessingIndex(), RelationGetRelationName, RelationGetRelid, SysScanDescData::scan, ScanKeyData::sk_attno, SysScanDescData::slot, SysScanDescData::snapshot, table_slot_create(), and WARNING.

Referenced by BuildEventTriggerCache(), 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().

620 {
621  SysScanDesc sysscan;
622  int i;
623 
624  /* REINDEX can probably be a hard error here ... */
625  if (ReindexIsProcessingIndex(RelationGetRelid(indexRelation)))
626  elog(ERROR, "cannot do ordered scan on index \"%s\", because it is being reindexed",
627  RelationGetRelationName(indexRelation));
628  /* ... but we only throw a warning about violating IgnoreSystemIndexes */
630  elog(WARNING, "using index \"%s\" despite IgnoreSystemIndexes",
631  RelationGetRelationName(indexRelation));
632 
633  sysscan = (SysScanDesc) palloc(sizeof(SysScanDescData));
634 
635  sysscan->heap_rel = heapRelation;
636  sysscan->irel = indexRelation;
637  sysscan->slot = table_slot_create(heapRelation, NULL);
638 
639  if (snapshot == NULL)
640  {
641  Oid relid = RelationGetRelid(heapRelation);
642 
643  snapshot = RegisterSnapshot(GetCatalogSnapshot(relid));
644  sysscan->snapshot = snapshot;
645  }
646  else
647  {
648  /* Caller is responsible for any snapshot. */
649  sysscan->snapshot = NULL;
650  }
651 
652  /* Change attribute numbers to be index column numbers. */
653  for (i = 0; i < nkeys; i++)
654  {
655  int j;
656 
657  for (j = 0; j < IndexRelationGetNumberOfAttributes(indexRelation); j++)
658  {
659  if (key[i].sk_attno == indexRelation->rd_index->indkey.values[j])
660  {
661  key[i].sk_attno = j + 1;
662  break;
663  }
664  }
665  if (j == IndexRelationGetNumberOfAttributes(indexRelation))
666  elog(ERROR, "column is not in index");
667  }
668 
669  sysscan->iscan = index_beginscan(heapRelation, indexRelation,
670  snapshot, nkeys, 0);
671  index_rescan(sysscan->iscan, key, nkeys, NULL, 0);
672  sysscan->scan = NULL;
673 
674  return sysscan;
675 }
TupleTableSlot * table_slot_create(Relation relation, List **reglist)
Definition: tableam.c:91
Relation irel
Definition: relscan.h:181
struct SysScanDescData * SysScanDesc
Definition: genam.h:88
Relation heap_rel
Definition: relscan.h:180
Snapshot RegisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:810
struct SnapshotData * snapshot
Definition: relscan.h:184
Snapshot GetCatalogSnapshot(Oid relid)
Definition: snapmgr.c:386
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:295
bool IgnoreSystemIndexes
Definition: miscinit.c:79
unsigned int Oid
Definition: postgres_ext.h:31
struct IndexScanDescData * iscan
Definition: relscan.h:183
struct TupleTableSlot * slot
Definition: relscan.h:185
Form_pg_index rd_index
Definition: rel.h:174
#define ERROR
Definition: elog.h:43
struct TableScanDescData * scan
Definition: relscan.h:182
#define IndexRelationGetNumberOfAttributes(relation)
Definition: rel.h:468
#define RelationGetRelationName(relation)
Definition: rel.h:490
#define WARNING
Definition: elog.h:40
void * palloc(Size size)
Definition: mcxt.c:950
#define elog(elevel,...)
Definition: elog.h:214
int i
bool ReindexIsProcessingIndex(Oid indexOid)
Definition: index.c:3845
#define RelationGetRelid(relation)
Definition: rel.h:456
AttrNumber sk_attno
Definition: skey.h:67
IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, int norderbys)
Definition: indexam.c:203

◆ systable_endscan()

void systable_endscan ( SysScanDesc  sysscan)

Definition at line 569 of file genam.c.

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(), AlterDomainDropConstraint(), AlterDomainValidateConstraint(), AlterExtensionNamespace(), AlterPolicy(), AlterSeqNamespaces(), AlterSetting(), AlterTypeRecurse(), ApplyExtensionUpdates(), ApplySetting(), ATExecAddOf(), ATExecAlterColumnType(), ATExecAlterConstraint(), ATExecAttachPartition(), ATExecDropConstraint(), ATExecDropExpression(), ATExecValidateConstraint(), ATPrepChangePersistence(), AttrDefaultFetch(), change_owner_fix_column_acls(), change_owner_recurse_to_sequences(), changeDependenciesOf(), changeDependenciesOn(), changeDependencyFor(), CheckConstraintFetch(), checkSharedDependencies(), ChooseConstraintName(), CloneFkReferenced(), CloneRowTriggersToPartition(), ConstraintNameExists(), ConstraintNameIsUsed(), copyTemplateDependencies(), CountDBSubscriptions(), CreateComments(), CreateInheritance(), CreatePolicy(), CreateSharedComments(), CreateTrigger(), DefineOpClass(), DefineTSConfiguration(), DeleteAttributeTuples(), DeleteComments(), deleteDependencyRecordsFor(), deleteDependencyRecordsForClass(), deleteDependencyRecordsForSpecific(), DeleteInheritsTuple(), DeleteInitPrivs(), deleteOneObject(), DeleteSecurityLabel(), DeleteSharedComments(), DeleteSharedSecurityLabel(), DeleteSystemAttributeTuples(), drop_parent_dependency(), DropClonedTriggersFromPartition(), DropConfigurationMapping(), dropDatabaseDependencies(), DropObjectById(), DropRole(), EnableDisableTrigger(), EnumValuesDelete(), exec_object_restorecon(), ExecAlterExtensionStmt(), ExecGrant_Largeobject(), extension_config_remove(), fetch_statentries_for_relation(), find_composite_type_dependencies(), find_inheritance_children(), findDependentObjects(), get_catalog_object_by_oid(), get_constraint_index(), 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_object_address_attrdef(), 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(), getAutoExtensionsOfObject(), GetComment(), GetDatabaseTuple(), GetDatabaseTupleByOid(), GetDefaultOpClass(), getExtensionOfObject(), GetNewOidWithIndex(), getObjectDescription(), getObjectIdentityParts(), getOwnedSequences_internal(), GetParentedForeignKeyRefs(), GetPublicationRelations(), GetSecurityLabel(), GetSharedSecurityLabel(), GetSubscriptionNotReadyRelations(), GetSubscriptionRelations(), has_superclass(), heap_truncate_find_FKs(), index_concurrently_swap(), IndexSetParentIndex(), isObjectPinned(), isSharedObjectPinned(), LargeObjectDrop(), LargeObjectExists(), load_domaintype_info(), load_enum_cache_data(), LookupOpclassInfo(), makeConfigurationDependencies(), MakeConfigurationMapping(), MergeConstraintsIntoExisting(), MergeWithExistingConstraint(), movedb(), myLargeObjectExists(), pg_extension_config_dump(), pg_extension_ownercheck(), pg_get_constraintdef_worker(), pg_get_serial_sequence(), pg_get_triggerdef_worker(), pg_largeobject_aclmask_snapshot(), pg_largeobject_ownercheck(), RangeDelete(), recordExtensionInitPrivWorker(), recordExtObjInitPriv(), relation_has_policies(), RelationBuildPartitionDesc(), RelationBuildRowSecurity(), RelationBuildRuleLock(), RelationBuildTriggers(), RelationBuildTupleDesc(), RelationGetExclusionInfo(), RelationGetFKeyList(), RelationGetIndexList(), RelationGetStatExtList(), RelationRemoveInheritance(), RelidByRelfilenode(), RemoveAttrDefault(), RemoveAttrDefaultById(), RemoveExtensionById(), RemoveInheritance(), RemovePolicyById(), RemoveRewriteRuleById(), RemoveRoleFromObjectACL(), RemoveRoleFromObjectPolicy(), RemoveStatistics(), RemoveTriggerById(), RemoveTSConfigurationById(), rename_policy(), renametrig(), 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(), tryAttachPartitionForeignKey(), typeInheritsFrom(), vac_update_datfrozenxid(), and validatePartitionedIndex().

570 {
571  if (sysscan->slot)
572  {
574  sysscan->slot = NULL;
575  }
576 
577  if (sysscan->irel)
578  {
579  index_endscan(sysscan->iscan);
580  index_close(sysscan->irel, AccessShareLock);
581  }
582  else
583  table_endscan(sysscan->scan);
584 
585  if (sysscan->snapshot)
586  UnregisterSnapshot(sysscan->snapshot);
587 
588  /*
589  * Reset the bsysscan flag at the end of the systable scan. See
590  * detailed comments in xact.c where these variables are declared.
591  */
593  bsysscan = false;
594 
595  pfree(sysscan);
596 }
Relation irel
Definition: relscan.h:181
struct SnapshotData * snapshot
Definition: relscan.h:184
#define AccessShareLock
Definition: lockdefs.h:36
struct IndexScanDescData * iscan
Definition: relscan.h:183
struct TupleTableSlot * slot
Definition: relscan.h:185
void pfree(void *pointer)
Definition: mcxt.c:1057
struct TableScanDescData * scan
Definition: relscan.h:182
bool bsysscan
Definition: xact.c:96
void ExecDropSingleTupleTableSlot(TupleTableSlot *slot)
Definition: execTuples.c:1224
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:321
void UnregisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:852
TransactionId CheckXidAlive
Definition: xact.c:95
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:158
static void table_endscan(TableScanDesc scan)
Definition: tableam.h:863
#define TransactionIdIsValid(xid)
Definition: transam.h:41

◆ systable_endscan_ordered()

void systable_endscan_ordered ( SysScanDesc  sysscan)

Definition at line 706 of file genam.c.

References Assert, ExecDropSingleTupleTableSlot(), index_endscan(), SysScanDescData::irel, SysScanDescData::iscan, pfree(), SysScanDescData::slot, SysScanDescData::snapshot, and UnregisterSnapshot().

Referenced by BuildEventTriggerCache(), 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().

707 {
708  if (sysscan->slot)
709  {
711  sysscan->slot = NULL;
712  }
713 
714  Assert(sysscan->irel);
715  index_endscan(sysscan->iscan);
716  if (sysscan->snapshot)
717  UnregisterSnapshot(sysscan->snapshot);
718  pfree(sysscan);
719 }
Relation irel
Definition: relscan.h:181
struct SnapshotData * snapshot
Definition: relscan.h:184
struct IndexScanDescData * iscan
Definition: relscan.h:183
struct TupleTableSlot * slot
Definition: relscan.h:185
void pfree(void *pointer)
Definition: mcxt.c:1057
void ExecDropSingleTupleTableSlot(TupleTableSlot *slot)
Definition: execTuples.c:1224
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:321
void UnregisterSnapshot(Snapshot snapshot)
Definition: snapmgr.c:852
#define Assert(condition)
Definition: c.h:745

◆ systable_getnext()

HeapTuple systable_getnext ( SysScanDesc  sysscan)

Definition at line 476 of file genam.c.

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(), AlterDomainDropConstraint(), AlterDomainValidateConstraint(), AlterExtensionNamespace(), AlterPolicy(), AlterSeqNamespaces(), AlterSetting(), AlterTypeRecurse(), ApplyExtensionUpdates(), ApplySetting(), ATExecAddOf(), ATExecAlterColumnType(), ATExecAlterConstraint(), ATExecAttachPartition(), ATExecDropConstraint(), ATExecDropExpression(), ATExecValidateConstraint(), ATPrepChangePersistence(), AttrDefaultFetch(), change_owner_fix_column_acls(), change_owner_recurse_to_sequences(), changeDependenciesOf(), changeDependenciesOn(), changeDependencyFor(), CheckConstraintFetch(), checkSharedDependencies(), ChooseConstraintName(), CloneFkReferenced(), CloneRowTriggersToPartition(), ConstraintNameExists(), ConstraintNameIsUsed(), copyTemplateDependencies(), CountDBSubscriptions(), CreateComments(), CreateInheritance(), CreatePolicy(), CreateSharedComments(), CreateTrigger(), DefineOpClass(), DefineTSConfiguration(), DeleteAttributeTuples(), DeleteComments(), deleteDependencyRecordsFor(), deleteDependencyRecordsForClass(), deleteDependencyRecordsForSpecific(), DeleteInheritsTuple(), DeleteInitPrivs(), deleteOneObject(), DeleteSecurityLabel(), DeleteSharedComments(), DeleteSharedSecurityLabel(), DeleteSystemAttributeTuples(), drop_parent_dependency(), DropClonedTriggersFromPartition(), DropConfigurationMapping(), dropDatabaseDependencies(), DropObjectById(), DropRole(), EnableDisableTrigger(), EnumValuesDelete(), exec_object_restorecon(), ExecAlterExtensionStmt(), ExecGrant_Largeobject(), extension_config_remove(), fetch_statentries_for_relation(), find_composite_type_dependencies(), find_inheritance_children(), findDependentObjects(), get_catalog_object_by_oid(), get_constraint_index(), 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_object_address_attrdef(), 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(), getAutoExtensionsOfObject(), GetComment(), GetDatabaseTuple(), GetDatabaseTupleByOid(), GetDefaultOpClass(), getExtensionOfObject(), GetNewOidWithIndex(), getObjectDescription(), getObjectIdentityParts(), getOwnedSequences_internal(), GetParentedForeignKeyRefs(), GetPublicationRelations(), GetSecurityLabel(), GetSharedSecurityLabel(), GetSubscriptionNotReadyRelations(), GetSubscriptionRelations(), has_superclass(), heap_truncate_find_FKs(), index_concurrently_swap(), IndexSetParentIndex(), isObjectPinned(), isSharedObjectPinned(), LargeObjectDrop(), LargeObjectExists(), load_domaintype_info(), load_enum_cache_data(), LookupOpclassInfo(), makeConfigurationDependencies(), MakeConfigurationMapping(), MergeConstraintsIntoExisting(), MergeWithExistingConstraint(), movedb(), myLargeObjectExists(), pg_extension_config_dump(), pg_extension_ownercheck(), pg_get_constraintdef_worker(), pg_get_serial_sequence(), pg_get_triggerdef_worker(), pg_largeobject_aclmask_snapshot(), pg_largeobject_ownercheck(), RangeDelete(), recordExtensionInitPrivWorker(), recordExtObjInitPriv(), relation_has_policies(), RelationBuildPartitionDesc(), RelationBuildRowSecurity(), RelationBuildRuleLock(), RelationBuildTriggers(), RelationBuildTupleDesc(), RelationGetExclusionInfo(), RelationGetFKeyList(), RelationGetIndexList(), RelationGetStatExtList(), RelationRemoveInheritance(), RelidByRelfilenode(), RemoveAttrDefault(), RemoveAttrDefaultById(), RemoveExtensionById(), RemoveInheritance(), RemovePolicyById(), RemoveRewriteRuleById(), RemoveRoleFromObjectACL(), RemoveRoleFromObjectPolicy(), RemoveStatistics(), RemoveTriggerById(), RemoveTSConfigurationById(), rename_policy(), renametrig(), 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(), tryAttachPartitionForeignKey(), typeInheritsFrom(), vac_update_datfrozenxid(), and validatePartitionedIndex().

477 {
478  HeapTuple htup = NULL;
479 
480  if (sysscan->irel)
481  {
482  if (index_getnext_slot(sysscan->iscan, ForwardScanDirection, sysscan->slot))
483  {
484  bool shouldFree;
485 
486  htup = ExecFetchSlotHeapTuple(sysscan->slot, false, &shouldFree);
487  Assert(!shouldFree);
488 
489  /*
490  * We currently don't need to support lossy index operators for
491  * any system catalog scan. It could be done here, using the scan
492  * keys to drive the operator calls, if we arranged to save the
493  * heap attnums during systable_beginscan(); this is practical
494  * because we still wouldn't need to support indexes on
495  * expressions.
496  */
497  if (sysscan->iscan->xs_recheck)
498  elog(ERROR, "system catalog scans with lossy index conditions are not implemented");
499  }
500  }
501  else
502  {
503  if (table_scan_getnextslot(sysscan->scan, ForwardScanDirection, sysscan->slot))
504  {
505  bool shouldFree;
506 
507  htup = ExecFetchSlotHeapTuple(sysscan->slot, false, &shouldFree);
508  Assert(!shouldFree);
509  }
510  }
511 
512  /*
513  * Handle the concurrent abort while fetching the catalog tuple during
514  * logical streaming of a transaction.
515  */
517 
518  return htup;
519 }
Relation irel
Definition: relscan.h:181
static bool table_scan_getnextslot(TableScanDesc sscan, ScanDirection direction, TupleTableSlot *slot)
Definition: tableam.h:904
struct IndexScanDescData * iscan
Definition: relscan.h:183
struct TupleTableSlot * slot
Definition: relscan.h:185
#define ERROR
Definition: elog.h:43
struct TableScanDescData * scan
Definition: relscan.h:182
HeapTuple ExecFetchSlotHeapTuple(TupleTableSlot *slot, bool materialize, bool *shouldFree)
Definition: execTuples.c:1614
#define Assert(condition)
Definition: c.h:745
bool index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
Definition: indexam.c:614
#define elog(elevel,...)
Definition: elog.h:214
static void HandleConcurrentAbort()
Definition: genam.c:453

◆ systable_getnext_ordered()

HeapTuple systable_getnext_ordered ( SysScanDesc  sysscan,
ScanDirection  direction 
)

Definition at line 681 of file genam.c.

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

Referenced by BuildEventTriggerCache(), 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().

682 {
683  HeapTuple htup = NULL;
684 
685  Assert(sysscan->irel);
686  if (index_getnext_slot(sysscan->iscan, direction, sysscan->slot))
687  htup = ExecFetchSlotHeapTuple(sysscan->slot, false, NULL);
688 
689  /* See notes in systable_getnext */
690  if (htup && sysscan->iscan->xs_recheck)
691  elog(ERROR, "system catalog scans with lossy index conditions are not implemented");
692 
693  /*
694  * Handle the concurrent abort while fetching the catalog tuple during
695  * logical streaming of a transaction.
696  */
698 
699  return htup;
700 }
Relation irel
Definition: relscan.h:181
struct IndexScanDescData * iscan
Definition: relscan.h:183
struct TupleTableSlot * slot
Definition: relscan.h:185
#define ERROR
Definition: elog.h:43
HeapTuple ExecFetchSlotHeapTuple(TupleTableSlot *slot, bool materialize, bool *shouldFree)
Definition: execTuples.c:1614
#define Assert(condition)
Definition: c.h:745
bool index_getnext_slot(IndexScanDesc scan, ScanDirection direction, TupleTableSlot *slot)
Definition: indexam.c:614
#define elog(elevel,...)
Definition: elog.h:214
static void HandleConcurrentAbort()
Definition: genam.c:453

◆ systable_recheck_tuple()

bool systable_recheck_tuple ( SysScanDesc  sysscan,
HeapTuple  tup 
)

Definition at line 535 of file genam.c.

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

Referenced by findDependentObjects(), and shdepDropOwned().

536 {
537  Snapshot freshsnap;
538  bool result;
539 
540  Assert(tup == ExecFetchSlotHeapTuple(sysscan->slot, false, NULL));
541 
542  /*
543  * Trust that table_tuple_satisfies_snapshot() and its subsidiaries
544  * (commonly LockBuffer() and HeapTupleSatisfiesMVCC()) do not themselves
545  * acquire snapshots, so we need not register the snapshot. Those
546  * facilities are too low-level to have any business scanning tables.
547  */
548  freshsnap = GetCatalogSnapshot(RelationGetRelid(sysscan->heap_rel));
549 
550  result = table_tuple_satisfies_snapshot(sysscan->heap_rel,
551  sysscan->slot,
552  freshsnap);
553 
554  /*
555  * Handle the concurrent abort while fetching the catalog tuple during
556  * logical streaming of a transaction.
557  */
559 
560  return result;
561 }
Relation heap_rel
Definition: relscan.h:180
Snapshot GetCatalogSnapshot(Oid relid)
Definition: snapmgr.c:386
struct TupleTableSlot * slot
Definition: relscan.h:185
HeapTuple ExecFetchSlotHeapTuple(TupleTableSlot *slot, bool materialize, bool *shouldFree)
Definition: execTuples.c:1614
static bool table_tuple_satisfies_snapshot(Relation rel, TupleTableSlot *slot, Snapshot snapshot)
Definition: tableam.h:1118
#define Assert(condition)
Definition: c.h:745
static void HandleConcurrentAbort()
Definition: genam.c:453
#define RelationGetRelid(relation)
Definition: rel.h:456