#include "utils/acl.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
+#include "utils/rls.h"
#include "utils/snapmgr.h"
#include "utils/tqual.h"
ScanDirection direction,
DestReceiver *dest);
static bool ExecCheckRTEPerms(RangeTblEntry *rte);
+static bool ExecCheckRTEPermsModified(Oid relOid, Oid userid,
+ Bitmapset *modifiedCols,
+ AclMode requiredPerms);
static void ExecCheckXactReadOnly(PlannedStmt *plannedstmt);
-static char *ExecBuildSlotValueDescription(TupleTableSlot *slot,
+static char *ExecBuildSlotValueDescription(Oid reloid,
+ TupleTableSlot *slot,
TupleDesc tupdesc,
+ Bitmapset *modifiedCols,
int maxfieldlen);
static void EvalPlanQualStart(EPQState *epqstate, EState *parentestate,
Plan *planTree);
+/*
+ * Note that GetUpdatedColumns() also exists in commands/trigger.c. There does
+ * not appear to be any good header to put it into, given the structures that
+ * it uses, so we let them be duplicated. Be sure to update both if one needs
+ * to be changed, however.
+ */
+#define GetInsertedColumns(relinfo, estate) \
+ (rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->insertedCols)
+#define GetUpdatedColumns(relinfo, estate) \
+ (rt_fetch((relinfo)->ri_RangeTableIndex, (estate)->es_range_table)->updatedCols)
+
/* end of local decls */
/*
* If the transaction is read-only, we need to check if any writes are
* planned to non-temporary tables. EXPLAIN is considered read-only.
+ *
+ * Don't allow writes in parallel mode. Supporting UPDATE and DELETE
+ * would require (a) storing the combocid hash in shared memory, rather
+ * than synchronizing it just once at the start of parallelism, and (b) an
+ * alternative to heap_update()'s reliance on xmax for mutual exclusion.
+ * INSERT may have no such troubles, but we forbid it to simplify the
+ * checks.
+ *
+ * We have lower-level defenses in CommandCounterIncrement and elsewhere
+ * against performing unsafe operations in parallel mode, but this gives a
+ * more user-friendly error message.
*/
- if (XactReadOnly && !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
+ if ((XactReadOnly || IsInParallelMode()) &&
+ !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
ExecCheckXactReadOnly(queryDesc->plannedstmt);
/*
if (!(eflags & (EXEC_FLAG_SKIP_TRIGGERS | EXEC_FLAG_EXPLAIN_ONLY)))
AfterTriggerBeginQuery();
+ /* Enter parallel mode, if required by the query. */
+ if (queryDesc->plannedstmt->parallelModeNeeded &&
+ !(eflags & EXEC_FLAG_EXPLAIN_ONLY))
+ EnterParallelMode();
+
MemoryContextSwitchTo(oldcontext);
}
direction,
dest);
+ /* Allow nodes to release or shut down resources. */
+ (void) ExecShutdownNode(queryDesc->planstate);
+
/*
* shutdown tuple receiver, if we started it
*/
*/
MemoryContextSwitchTo(oldcontext);
+ /* Exit parallel mode, if it was required by the query. */
+ if (queryDesc->plannedstmt->parallelModeNeeded &&
+ !(estate->es_top_eflags & EXEC_FLAG_EXPLAIN_ONLY))
+ ExitParallelMode();
+
/*
* Release EState and per-query memory context. This should release
* everything the executor has allocated.
AclMode remainingPerms;
Oid relOid;
Oid userid;
- int col;
/*
* Only plain-relation RTEs need to be checked here. Function RTEs are
remainingPerms = requiredPerms & ~relPerms;
if (remainingPerms != 0)
{
+ int col = -1;
+
/*
* If we lack any permissions that exist only as relation permissions,
* we can fail straight away.
return false;
}
- col = -1;
while ((col = bms_next_member(rte->selectedCols, col)) >= 0)
{
/* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
}
/*
- * Basically the same for the mod columns, with either INSERT or
- * UPDATE privilege as specified by remainingPerms.
+ * Basically the same for the mod columns, for both INSERT and UPDATE
+ * privilege as specified by remainingPerms.
*/
- remainingPerms &= ~ACL_SELECT;
- if (remainingPerms != 0)
- {
- /*
- * When the query doesn't explicitly change any columns, allow the
- * query if we have permission on any column of the rel. This is
- * to handle SELECT FOR UPDATE as well as possible corner cases in
- * INSERT and UPDATE.
- */
- if (bms_is_empty(rte->modifiedCols))
- {
- if (pg_attribute_aclcheck_all(relOid, userid, remainingPerms,
- ACLMASK_ANY) != ACLCHECK_OK)
- return false;
- }
+ if (remainingPerms & ACL_INSERT && !ExecCheckRTEPermsModified(relOid,
+ userid,
+ rte->insertedCols,
+ ACL_INSERT))
+ return false;
- col = -1;
- while ((col = bms_next_member(rte->modifiedCols, col)) >= 0)
- {
- /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
- AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
+ if (remainingPerms & ACL_UPDATE && !ExecCheckRTEPermsModified(relOid,
+ userid,
+ rte->updatedCols,
+ ACL_UPDATE))
+ return false;
+ }
+ return true;
+}
- if (attno == InvalidAttrNumber)
- {
- /* whole-row reference can't happen here */
- elog(ERROR, "whole-row update is not implemented");
- }
- else
- {
- if (pg_attribute_aclcheck(relOid, attno, userid,
- remainingPerms) != ACLCHECK_OK)
- return false;
- }
- }
+/*
+ * ExecCheckRTEPermsModified
+ * Check INSERT or UPDATE access permissions for a single RTE (these
+ * are processed uniformly).
+ */
+static bool
+ExecCheckRTEPermsModified(Oid relOid, Oid userid, Bitmapset *modifiedCols,
+ AclMode requiredPerms)
+{
+ int col = -1;
+
+ /*
+ * When the query doesn't explicitly update any columns, allow the query
+ * if we have permission on any column of the rel. This is to handle
+ * SELECT FOR UPDATE as well as possible corner cases in UPDATE.
+ */
+ if (bms_is_empty(modifiedCols))
+ {
+ if (pg_attribute_aclcheck_all(relOid, userid, requiredPerms,
+ ACLMASK_ANY) != ACLCHECK_OK)
+ return false;
+ }
+
+ while ((col = bms_next_member(modifiedCols, col)) >= 0)
+ {
+ /* bit #s are offset by FirstLowInvalidHeapAttributeNumber */
+ AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
+
+ if (attno == InvalidAttrNumber)
+ {
+ /* whole-row reference can't happen here */
+ elog(ERROR, "whole-row update is not implemented");
+ }
+ else
+ {
+ if (pg_attribute_aclcheck(relOid, attno, userid,
+ requiredPerms) != ACLCHECK_OK)
+ return false;
}
}
return true;
}
/*
- * Check that the query does not imply any writes to non-temp tables.
+ * Check that the query does not imply any writes to non-temp tables;
+ * unless we're in parallel mode, in which case don't even allow writes
+ * to temp tables.
*
* Note: in a Hot Standby slave this would need to reject writes to temp
- * tables as well; but an HS slave can't have created any temp tables
- * in the first place, so no need to check that.
+ * tables just as we do in parallel mode; but an HS slave can't have created
+ * any temp tables in the first place, so no need to check that.
*/
static void
ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
{
ListCell *l;
- /* Fail if write permissions are requested on any non-temp table */
+ /*
+ * Fail if write permissions are requested in parallel mode for table
+ * (temp or non-temp), otherwise fail for any non-temp table.
+ */
foreach(l, plannedstmt->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
PreventCommandIfReadOnly(CreateCommandTag((Node *) plannedstmt));
}
+
+ if (plannedstmt->commandType != CMD_SELECT || plannedstmt->hasModifyingCTE)
+ PreventCommandIfParallelMode(CreateCommandTag((Node *) plannedstmt));
}
if (rc->isParent)
continue;
+ /* get relation's OID (will produce InvalidOid if subquery) */
+ relid = getrelid(rc->rti, rangeTable);
+
+ /*
+ * If you change the conditions under which rel locks are acquired
+ * here, be sure to adjust ExecOpenScanRelation to match.
+ */
switch (rc->markType)
{
case ROW_MARK_EXCLUSIVE:
case ROW_MARK_NOKEYEXCLUSIVE:
case ROW_MARK_SHARE:
case ROW_MARK_KEYSHARE:
- relid = getrelid(rc->rti, rangeTable);
relation = heap_open(relid, RowShareLock);
break;
case ROW_MARK_REFERENCE:
- relid = getrelid(rc->rti, rangeTable);
relation = heap_open(relid, AccessShareLock);
break;
case ROW_MARK_COPY:
- /* there's no real table here ... */
+ /* no physical table access is required */
relation = NULL;
break;
default:
erm = (ExecRowMark *) palloc(sizeof(ExecRowMark));
erm->relation = relation;
+ erm->relid = relid;
erm->rti = rc->rti;
erm->prti = rc->prti;
erm->rowmarkId = rc->rowmarkId;
erm->markType = rc->markType;
+ erm->strength = rc->strength;
erm->waitPolicy = rc->waitPolicy;
+ erm->ermActive = false;
ItemPointerSetInvalid(&(erm->curCtid));
+ erm->ermExtra = NULL;
estate->es_rowMarks = lappend(estate->es_rowMarks, erm);
}
static void
CheckValidRowMarkRel(Relation rel, RowMarkType markType)
{
+ FdwRoutine *fdwroutine;
+
switch (rel->rd_rel->relkind)
{
case RELKIND_RELATION:
RelationGetRelationName(rel))));
break;
case RELKIND_FOREIGN_TABLE:
- /* Should not get here; planner should have used ROW_MARK_COPY */
- ereport(ERROR,
- (errcode(ERRCODE_WRONG_OBJECT_TYPE),
- errmsg("cannot lock rows in foreign table \"%s\"",
- RelationGetRelationName(rel))));
+ /* Okay only if the FDW supports it */
+ fdwroutine = GetFdwRoutineForRelation(rel, false);
+ if (fdwroutine->RefetchForeignRow == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot lock rows in foreign table \"%s\"",
+ RelationGetRelationName(rel))));
break;
default:
ereport(ERROR,
Relation rel = resultRelInfo->ri_RelationDesc;
TupleDesc tupdesc = RelationGetDescr(rel);
TupleConstr *constr = tupdesc->constr;
+ Bitmapset *modifiedCols;
+ Bitmapset *insertedCols;
+ Bitmapset *updatedCols;
Assert(constr);
{
if (tupdesc->attrs[attrChk - 1]->attnotnull &&
slot_attisnull(slot, attrChk))
+ {
+ char *val_desc;
+
+ insertedCols = GetInsertedColumns(resultRelInfo, estate);
+ updatedCols = GetUpdatedColumns(resultRelInfo, estate);
+ modifiedCols = bms_union(insertedCols, updatedCols);
+ val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+ slot,
+ tupdesc,
+ modifiedCols,
+ 64);
+
ereport(ERROR,
(errcode(ERRCODE_NOT_NULL_VIOLATION),
errmsg("null value in column \"%s\" violates not-null constraint",
NameStr(tupdesc->attrs[attrChk - 1]->attname)),
- errdetail("Failing row contains %s.",
- ExecBuildSlotValueDescription(slot,
- tupdesc,
- 64)),
+ val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
errtablecol(rel, attrChk)));
+ }
}
}
const char *failed;
if ((failed = ExecRelCheck(resultRelInfo, slot, estate)) != NULL)
+ {
+ char *val_desc;
+
+ insertedCols = GetInsertedColumns(resultRelInfo, estate);
+ updatedCols = GetUpdatedColumns(resultRelInfo, estate);
+ modifiedCols = bms_union(insertedCols, updatedCols);
+ val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+ slot,
+ tupdesc,
+ modifiedCols,
+ 64);
ereport(ERROR,
(errcode(ERRCODE_CHECK_VIOLATION),
errmsg("new row for relation \"%s\" violates check constraint \"%s\"",
RelationGetRelationName(rel), failed),
- errdetail("Failing row contains %s.",
- ExecBuildSlotValueDescription(slot,
- tupdesc,
- 64)),
+ val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
errtableconstraint(rel, failed)));
+ }
}
}
/*
* ExecWithCheckOptions -- check that tuple satisfies any WITH CHECK OPTIONs
+ * of the specified kind.
+ *
+ * Note that this needs to be called multiple times to ensure that all kinds of
+ * WITH CHECK OPTIONs are handled (both those from views which have the WITH
+ * CHECK OPTION set and from row level security policies). See ExecInsert()
+ * and ExecUpdate().
*/
void
-ExecWithCheckOptions(ResultRelInfo *resultRelInfo,
+ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
TupleTableSlot *slot, EState *estate)
{
+ Relation rel = resultRelInfo->ri_RelationDesc;
+ TupleDesc tupdesc = RelationGetDescr(rel);
ExprContext *econtext;
ListCell *l1,
*l2;
WithCheckOption *wco = (WithCheckOption *) lfirst(l1);
ExprState *wcoExpr = (ExprState *) lfirst(l2);
+ /*
+ * Skip any WCOs which are not the kind we are looking for at this
+ * time.
+ */
+ if (wco->kind != kind)
+ continue;
+
/*
* WITH CHECK OPTION checks are intended to ensure that the new tuple
* is visible (in the case of a view) or that it passes the
- * 'with-check' policy (in the case of row security).
- * If the qual evaluates to NULL or FALSE, then the new tuple won't be
- * included in the view or doesn't pass the 'with-check' policy for the
- * table. We need ExecQual to return FALSE for NULL to handle the view
- * case (the opposite of what we do above for CHECK constraints).
+ * 'with-check' policy (in the case of row security). If the qual
+ * evaluates to NULL or FALSE, then the new tuple won't be included in
+ * the view or doesn't pass the 'with-check' policy for the table. We
+ * need ExecQual to return FALSE for NULL to handle the view case (the
+ * opposite of what we do above for CHECK constraints).
*/
if (!ExecQual((List *) wcoExpr, econtext, false))
- ereport(ERROR,
- (errcode(ERRCODE_WITH_CHECK_OPTION_VIOLATION),
- errmsg("new row violates WITH CHECK OPTION for \"%s\"",
- wco->viewname),
- errdetail("Failing row contains %s.",
- ExecBuildSlotValueDescription(slot,
- RelationGetDescr(resultRelInfo->ri_RelationDesc),
- 64))));
+ {
+ char *val_desc;
+ Bitmapset *modifiedCols;
+ Bitmapset *insertedCols;
+ Bitmapset *updatedCols;
+
+ switch (wco->kind)
+ {
+ /*
+ * For WITH CHECK OPTIONs coming from views, we might be
+ * able to provide the details on the row, depending on
+ * the permissions on the relation (that is, if the user
+ * could view it directly anyway). For RLS violations, we
+ * don't include the data since we don't know if the user
+ * should be able to view the tuple as as that depends on
+ * the USING policy.
+ */
+ case WCO_VIEW_CHECK:
+ insertedCols = GetInsertedColumns(resultRelInfo, estate);
+ updatedCols = GetUpdatedColumns(resultRelInfo, estate);
+ modifiedCols = bms_union(insertedCols, updatedCols);
+ val_desc = ExecBuildSlotValueDescription(RelationGetRelid(rel),
+ slot,
+ tupdesc,
+ modifiedCols,
+ 64);
+
+ ereport(ERROR,
+ (errcode(ERRCODE_WITH_CHECK_OPTION_VIOLATION),
+ errmsg("new row violates WITH CHECK OPTION for \"%s\"",
+ wco->relname),
+ val_desc ? errdetail("Failing row contains %s.",
+ val_desc) : 0));
+ break;
+ case WCO_RLS_INSERT_CHECK:
+ case WCO_RLS_UPDATE_CHECK:
+ if (wco->polname != NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy \"%s\" for \"%s\"",
+ wco->polname, wco->relname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy for \"%s\"",
+ wco->relname)));
+ break;
+ case WCO_RLS_CONFLICT_CHECK:
+ if (wco->polname != NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy \"%s\" (USING expression) for \"%s\"",
+ wco->polname, wco->relname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("new row violates row level security policy (USING expression) for \"%s\"",
+ wco->relname)));
+ break;
+ default:
+ elog(ERROR, "unrecognized WCO kind: %u", wco->kind);
+ break;
+ }
+ }
}
}
* dropped columns. We used to use the slot's tuple descriptor to decode the
* data, but the slot's descriptor doesn't identify dropped columns, so we
* now need to be passed the relation's descriptor.
+ *
+ * Note that, like BuildIndexValueDescription, if the user does not have
+ * permission to view any of the columns involved, a NULL is returned. Unlike
+ * BuildIndexValueDescription, if the user has access to view a subset of the
+ * column involved, that subset will be returned with a key identifying which
+ * columns they are.
*/
static char *
-ExecBuildSlotValueDescription(TupleTableSlot *slot,
+ExecBuildSlotValueDescription(Oid reloid,
+ TupleTableSlot *slot,
TupleDesc tupdesc,
+ Bitmapset *modifiedCols,
int maxfieldlen)
{
StringInfoData buf;
+ StringInfoData collist;
bool write_comma = false;
+ bool write_comma_collist = false;
int i;
+ AclResult aclresult;
+ bool table_perm = false;
+ bool any_perm = false;
- /* Make sure the tuple is fully deconstructed */
- slot_getallattrs(slot);
+ /*
+ * Check if RLS is enabled and should be active for the relation; if so,
+ * then don't return anything. Otherwise, go through normal permission
+ * checks.
+ */
+ if (check_enable_rls(reloid, InvalidOid, true) == RLS_ENABLED)
+ return NULL;
initStringInfo(&buf);
appendStringInfoChar(&buf, '(');
+ /*
+ * Check if the user has permissions to see the row. Table-level SELECT
+ * allows access to all columns. If the user does not have table-level
+ * SELECT then we check each column and include those the user has SELECT
+ * rights on. Additionally, we always include columns the user provided
+ * data for.
+ */
+ aclresult = pg_class_aclcheck(reloid, GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ {
+ /* Set up the buffer for the column list */
+ initStringInfo(&collist);
+ appendStringInfoChar(&collist, '(');
+ }
+ else
+ table_perm = any_perm = true;
+
+ /* Make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
for (i = 0; i < tupdesc->natts; i++)
{
+ bool column_perm = false;
char *val;
int vallen;
if (tupdesc->attrs[i]->attisdropped)
continue;
- if (slot->tts_isnull[i])
- val = "null";
- else
+ if (!table_perm)
{
- Oid foutoid;
- bool typisvarlena;
+ /*
+ * No table-level SELECT, so need to make sure they either have
+ * SELECT rights on the column or that they have provided the data
+ * for the column. If not, omit this column from the error
+ * message.
+ */
+ aclresult = pg_attribute_aclcheck(reloid, tupdesc->attrs[i]->attnum,
+ GetUserId(), ACL_SELECT);
+ if (bms_is_member(tupdesc->attrs[i]->attnum - FirstLowInvalidHeapAttributeNumber,
+ modifiedCols) || aclresult == ACLCHECK_OK)
+ {
+ column_perm = any_perm = true;
- getTypeOutputInfo(tupdesc->attrs[i]->atttypid,
- &foutoid, &typisvarlena);
- val = OidOutputFunctionCall(foutoid, slot->tts_values[i]);
- }
+ if (write_comma_collist)
+ appendStringInfoString(&collist, ", ");
+ else
+ write_comma_collist = true;
- if (write_comma)
- appendStringInfoString(&buf, ", ");
- else
- write_comma = true;
+ appendStringInfoString(&collist, NameStr(tupdesc->attrs[i]->attname));
+ }
+ }
- /* truncate if needed */
- vallen = strlen(val);
- if (vallen <= maxfieldlen)
- appendStringInfoString(&buf, val);
- else
+ if (table_perm || column_perm)
{
- vallen = pg_mbcliplen(val, vallen, maxfieldlen);
- appendBinaryStringInfo(&buf, val, vallen);
- appendStringInfoString(&buf, "...");
+ if (slot->tts_isnull[i])
+ val = "null";
+ else
+ {
+ Oid foutoid;
+ bool typisvarlena;
+
+ getTypeOutputInfo(tupdesc->attrs[i]->atttypid,
+ &foutoid, &typisvarlena);
+ val = OidOutputFunctionCall(foutoid, slot->tts_values[i]);
+ }
+
+ if (write_comma)
+ appendStringInfoString(&buf, ", ");
+ else
+ write_comma = true;
+
+ /* truncate if needed */
+ vallen = strlen(val);
+ if (vallen <= maxfieldlen)
+ appendStringInfoString(&buf, val);
+ else
+ {
+ vallen = pg_mbcliplen(val, vallen, maxfieldlen);
+ appendBinaryStringInfo(&buf, val, vallen);
+ appendStringInfoString(&buf, "...");
+ }
}
}
+ /* If we end up with zero columns being returned, then return NULL. */
+ if (!any_perm)
+ return NULL;
+
appendStringInfoChar(&buf, ')');
+ if (!table_perm)
+ {
+ appendStringInfoString(&collist, ") = ");
+ appendStringInfoString(&collist, buf.data);
+
+ return collist.data;
+ }
+
return buf.data;
}
+/*
+ * ExecUpdateLockMode -- find the appropriate UPDATE tuple lock mode for a
+ * given ResultRelInfo
+ */
+LockTupleMode
+ExecUpdateLockMode(EState *estate, ResultRelInfo *relinfo)
+{
+ Bitmapset *keyCols;
+ Bitmapset *updatedCols;
+
+ /*
+ * Compute lock mode to use. If columns that are part of the key have not
+ * been modified, then we can use a weaker lock, allowing for better
+ * concurrency.
+ */
+ updatedCols = GetUpdatedColumns(relinfo, estate);
+ keyCols = RelationGetIndexAttrBitmap(relinfo->ri_RelationDesc,
+ INDEX_ATTR_BITMAP_KEY);
+
+ if (bms_overlap(keyCols, updatedCols))
+ return LockTupleExclusive;
+
+ return LockTupleNoKeyExclusive;
+}
+
/*
* ExecFindRowMark -- find the ExecRowMark struct for given rangetable index
+ *
+ * If no such struct, either return NULL or throw error depending on missing_ok
*/
ExecRowMark *
-ExecFindRowMark(EState *estate, Index rti)
+ExecFindRowMark(EState *estate, Index rti, bool missing_ok)
{
ListCell *lc;
if (erm->rti == rti)
return erm;
}
- elog(ERROR, "failed to find ExecRowMark for rangetable index %u", rti);
- return NULL; /* keep compiler quiet */
+ if (!missing_ok)
+ elog(ERROR, "failed to find ExecRowMark for rangetable index %u", rti);
+ return NULL;
}
/*
aerm->rowmark = erm;
/* Look up the resjunk columns associated with this rowmark */
- if (erm->relation)
+ if (erm->markType != ROW_MARK_COPY)
{
- Assert(erm->markType != ROW_MARK_COPY);
-
- /* if child rel, need tableoid */
- if (erm->rti != erm->prti)
- {
- snprintf(resname, sizeof(resname), "tableoid%u", erm->rowmarkId);
- aerm->toidAttNo = ExecFindJunkAttributeInTlist(targetlist,
- resname);
- if (!AttributeNumberIsValid(aerm->toidAttNo))
- elog(ERROR, "could not find junk %s column", resname);
- }
-
- /* always need ctid for real relations */
+ /* need ctid for all methods other than COPY */
snprintf(resname, sizeof(resname), "ctid%u", erm->rowmarkId);
aerm->ctidAttNo = ExecFindJunkAttributeInTlist(targetlist,
resname);
}
else
{
- Assert(erm->markType == ROW_MARK_COPY);
-
+ /* need wholerow if COPY */
snprintf(resname, sizeof(resname), "wholerow%u", erm->rowmarkId);
aerm->wholeAttNo = ExecFindJunkAttributeInTlist(targetlist,
resname);
elog(ERROR, "could not find junk %s column", resname);
}
+ /* if child rel, need tableoid */
+ if (erm->rti != erm->prti)
+ {
+ snprintf(resname, sizeof(resname), "tableoid%u", erm->rowmarkId);
+ aerm->toidAttNo = ExecFindJunkAttributeInTlist(targetlist,
+ resname);
+ if (!AttributeNumberIsValid(aerm->toidAttNo))
+ elog(ERROR, "could not find junk %s column", resname);
+ }
+
return aerm;
}
* recycled and reused for an unrelated tuple. This implies that
* the latest version of the row was deleted, so we need do
* nothing. (Should be safe to examine xmin without getting
- * buffer's content lock, since xmin never changes in an existing
- * tuple.)
+ * buffer's content lock. We assume reading a TransactionId to be
+ * atomic, and Xmin never changes in an existing tuple, except to
+ * invalid or frozen, and neither of those can match priorXmax.)
*/
if (!TransactionIdEquals(HeapTupleHeaderGetXmin(tuple.t_data),
priorXmax))
{
case LockWaitBlock:
XactLockTableWait(SnapshotDirty.xmax,
- relation, &tuple.t_data->t_ctid,
+ relation, &tuple.t_self,
XLTW_FetchUpdated);
break;
case LockWaitSkip:
if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
- return NULL; /* skip instead of waiting */
+ return NULL; /* skip instead of waiting */
break;
case LockWaitError:
if (!ConditionalXactLockTableWait(SnapshotDirty.xmax))
ereport(ERROR,
(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
errmsg("could not obtain lock on row in relation \"%s\"",
- RelationGetRelationName(relation))));
+ RelationGetRelationName(relation))));
break;
}
continue; /* loop back to repeat heap_fetch */
* case, so as to avoid the "Halloween problem" of
* repeated update attempts. In the latter case it might
* be sensible to fetch the updated tuple instead, but
- * doing so would require changing heap_lock_tuple as well
- * as heap_update and heap_delete to not complain about
- * updating "invisible" tuples, which seems pretty scary.
- * So for now, treat the tuple as deleted and do not
- * process.
+ * doing so would require changing heap_update and
+ * heap_delete to not complain about updating "invisible"
+ * tuples, which seems pretty scary (heap_lock_tuple will
+ * not complain, but few callers expect
+ * HeapTupleInvisible, and we're not one of them). So for
+ * now, treat the tuple as deleted and do not process.
*/
ReleaseBuffer(buffer);
return NULL;
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("could not serialize access due to concurrent update")));
+
+ /* Should not encounter speculative tuple on recheck */
+ Assert(!HeapTupleHeaderIsSpeculative(tuple.t_data));
if (!ItemPointerEquals(&hufd.ctid, &tuple.t_self))
{
/* it was updated, so look at the updated version */
ReleaseBuffer(buffer);
return NULL;
+ case HeapTupleInvisible:
+ elog(ERROR, "attempted to lock invisible tuple");
+
default:
ReleaseBuffer(buffer);
elog(ERROR, "unrecognized heap_lock_tuple status: %u",
/*
* EvalPlanQualSetPlan -- set or change subplan of an EPQState.
*
- * We need this so that ModifyTuple can deal with multiple subplans.
+ * We need this so that ModifyTable can deal with multiple subplans.
*/
void
EvalPlanQualSetPlan(EPQState *epqstate, Plan *subplan, List *auxrowmarks)
/* clear any leftover test tuple for this rel */
EvalPlanQualSetTuple(epqstate, erm->rti, NULL);
- if (erm->relation)
+ /* if child rel, must check whether it produced this row */
+ if (erm->rti != erm->prti)
{
- Buffer buffer;
+ Oid tableoid;
- Assert(erm->markType == ROW_MARK_REFERENCE);
+ datum = ExecGetJunkAttribute(epqstate->origslot,
+ aerm->toidAttNo,
+ &isNull);
+ /* non-locked rels could be on the inside of outer joins */
+ if (isNull)
+ continue;
+ tableoid = DatumGetObjectId(datum);
- /* if child rel, must check whether it produced this row */
- if (erm->rti != erm->prti)
+ Assert(OidIsValid(erm->relid));
+ if (tableoid != erm->relid)
{
- Oid tableoid;
+ /* this child is inactive right now */
+ continue;
+ }
+ }
- datum = ExecGetJunkAttribute(epqstate->origslot,
- aerm->toidAttNo,
- &isNull);
- /* non-locked rels could be on the inside of outer joins */
- if (isNull)
- continue;
- tableoid = DatumGetObjectId(datum);
+ if (erm->markType == ROW_MARK_REFERENCE)
+ {
+ HeapTuple copyTuple;
- if (tableoid != RelationGetRelid(erm->relation))
- {
- /* this child is inactive right now */
- continue;
- }
- }
+ Assert(erm->relation != NULL);
/* fetch the tuple's ctid */
datum = ExecGetJunkAttribute(epqstate->origslot,
/* non-locked rels could be on the inside of outer joins */
if (isNull)
continue;
- tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
- /* okay, fetch the tuple */
- if (!heap_fetch(erm->relation, SnapshotAny, &tuple, &buffer,
- false, NULL))
- elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
+ /* fetch requests on foreign tables must be passed to their FDW */
+ if (erm->relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ {
+ FdwRoutine *fdwroutine;
+ bool updated = false;
+
+ fdwroutine = GetFdwRoutineForRelation(erm->relation, false);
+ /* this should have been checked already, but let's be safe */
+ if (fdwroutine->RefetchForeignRow == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot lock rows in foreign table \"%s\"",
+ RelationGetRelationName(erm->relation))));
+ copyTuple = fdwroutine->RefetchForeignRow(epqstate->estate,
+ erm,
+ datum,
+ &updated);
+ if (copyTuple == NULL)
+ elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
+
+ /*
+ * Ideally we'd insist on updated == false here, but that
+ * assumes that FDWs can track that exactly, which they might
+ * not be able to. So just ignore the flag.
+ */
+ }
+ else
+ {
+ /* ordinary table, fetch the tuple */
+ Buffer buffer;
- /* successful, copy and store tuple */
- EvalPlanQualSetTuple(epqstate, erm->rti,
- heap_copytuple(&tuple));
- ReleaseBuffer(buffer);
+ tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
+ if (!heap_fetch(erm->relation, SnapshotAny, &tuple, &buffer,
+ false, NULL))
+ elog(ERROR, "failed to fetch tuple for EvalPlanQual recheck");
+
+ /* successful, copy tuple */
+ copyTuple = heap_copytuple(&tuple);
+ ReleaseBuffer(buffer);
+ }
+
+ /* store tuple */
+ EvalPlanQualSetTuple(epqstate, erm->rti, copyTuple);
}
else
{
/* build a temporary HeapTuple control structure */
tuple.t_len = HeapTupleHeaderGetDatumLength(td);
- ItemPointerSetInvalid(&(tuple.t_self));
- tuple.t_tableOid = InvalidOid;
tuple.t_data = td;
+ /* relation might be a foreign table, if so provide tableoid */
+ tuple.t_tableOid = erm->relid;
+ /* also copy t_ctid in case there's valid data there */
+ tuple.t_self = td->t_ctid;
/* copy and store tuple */
EvalPlanQualSetTuple(epqstate, erm->rti,
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