/*
* HeapTupleSatisfiesToast
* True iff heap tuple is valid as a TOAST row.
*
* This is a simplified version that only checks for VACUUM moving conditions.
* It's appropriate for TOAST usage because TOAST really doesn't want to do
* its own time qual checks; if you can see the main table row that contains
* a TOAST reference, you should be able to see the TOASTed value. However,
* vacuuming a TOAST table is independent of the main table, and in case such
* a vacuum fails partway through, we'd better do this much checking.
*
* Among other things, this means you can't do UPDATEs of rows in a TOAST
* table.
*/
bool
HeapTupleSatisfiesToast(HeapTuple htup, Snapshot snapshot,
Buffer buffer)
{
HeapTupleHeader tuple = htup->t_data;
Assert(ItemPointerIsValid(&htup->t_self));
Assert(htup->t_tableOid != InvalidOid);
if (!HeapTupleHeaderXminCommitted(tuple))
{
if (HeapTupleHeaderXminInvalid(tuple))
return false;
/* Used by pre-9.0 binary upgrades */
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
}
}
/* otherwise assume the tuple is valid for TOAST. */
return true;
}
/*
* HeapTupleSatisfiesToast
* True iff heap tuple is valid as a TOAST row.
*
* This is a simplified version that only checks for VACUUM moving conditions.
* It's appropriate for TOAST usage because TOAST really doesn't want to do
* its own time qual checks; if you can see the main table row that contains
* a TOAST reference, you should be able to see the TOASTed value. However,
* vacuuming a TOAST table is independent of the main table, and in case such
* a vacuum fails partway through, we'd better do this much checking.
*
* Among other things, this means you can't do UPDATEs of rows in a TOAST
* table.
*/
bool
HeapTupleSatisfiesToast(HeapTupleHeader tuple, Snapshot snapshot,
Buffer buffer)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
/* Used by pre-9.0 binary upgrades */
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
}
}
/* otherwise assume the tuple is valid for TOAST. */
return true;
}
/*
* HeapTupleSatisfiesToast
* True iff heap tuple is valid as a TOAST row.
*
* This is a simplified version that only checks for VACUUM moving conditions.
* It's appropriate for TOAST usage because TOAST really doesn't want to do
* its own time qual checks; if you can see the main table row that contains
* a TOAST reference, you should be able to see the TOASTed value. However,
* vacuuming a TOAST table is independent of the main table, and in case such
* a vacuum fails partway through, we'd better do this much checking.
*
* Among other things, this means you can't do UPDATEs of rows in a TOAST
* table.
*/
bool
HeapTupleSatisfiesToast(HeapTupleHeader tuple)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
}
}
}
/* otherwise assume the tuple is valid for TOAST. */
return true;
}
CommandId
HeapTupleHeaderGetCmax(HeapTupleHeader tup)
{
CommandId cid = HeapTupleHeaderGetRawCommandId(tup);
Assert(!(tup->t_infomask & HEAP_MOVED));
Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(tup)));
if (tup->t_infomask & HEAP_COMBOCID)
return GetRealCmax(cid);
else
return cid;
}
CommandId
HeapTupleHeaderGetCmax(HeapTupleHeader tup)
{
CommandId cid = HeapTupleHeaderGetRawCommandId(tup);
/* We do not store cmax when locking a tuple */
Assert(!(tup->t_infomask & (HEAP_MOVED | HEAP_IS_LOCKED)));
Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tup)));
if (tup->t_infomask & HEAP_COMBOCID)
return GetRealCmax(cid);
else
return cid;
}
CommandId
HeapTupleHeaderGetCmax(HeapTupleHeader tup)
{
CommandId cid = HeapTupleHeaderGetRawCommandId(tup);
/* We do not store cmax when locking a tuple */
Assert(!(tup->t_infomask & (HEAP_MOVED | HEAP_IS_LOCKED)));
/*
* MPP-8317: cursors can't always *tell* that this is the current transaction.
*/
Assert(QEDtxContextInfo.cursorContext || TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tup)));
if (tup->t_infomask & HEAP_COMBOCID)
return GetRealCmax(HeapTupleHeaderGetXmin(tup), cid);
else
return cid;
}
/*
* Is the tuple really only locked? That is, is it not updated?
*
* It's easy to check just infomask bits if the locker is not a multi; but
* otherwise we need to verify that the updating transaction has not aborted.
*
* This function is here because it follows the same time qualification rules
* laid out at the top of this file.
*/
bool
HeapTupleHeaderIsOnlyLocked(HeapTupleHeader tuple)
{
TransactionId xmax;
/* if there's no valid Xmax, then there's obviously no update either */
if (tuple->t_infomask & HEAP_XMAX_INVALID)
return true;
if (tuple->t_infomask & HEAP_XMAX_LOCK_ONLY)
return true;
/* invalid xmax means no update */
if (!TransactionIdIsValid(HeapTupleHeaderGetRawXmax(tuple)))
return true;
/*
* if HEAP_XMAX_LOCK_ONLY is not set and not a multi, then this must
* necessarily have been updated
*/
if (!(tuple->t_infomask & HEAP_XMAX_IS_MULTI))
return false;
/* ... but if it's a multi, then perhaps the updating Xid aborted. */
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
if (TransactionIdIsCurrentTransactionId(xmax))
return false;
if (TransactionIdIsInProgress(xmax))
return false;
if (TransactionIdDidCommit(xmax))
return false;
/*
* not current, not in progress, not committed -- must have aborted or
* crashed
*/
return true;
}
CommandId
HeapTupleHeaderGetCmax(HeapTupleHeader tup)
{
CommandId cid = HeapTupleHeaderGetRawCommandId(tup);
Assert(!(tup->t_infomask & HEAP_MOVED));
/*
* Because GetUpdateXid() performs memory allocations if xmax is a
* multixact we can't Assert() if we're inside a critical section. This
* weakens the check, but not using GetCmax() inside one would complicate
* things too much.
*/
Assert(CritSectionCount > 0 ||
TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(tup)));
if (tup->t_infomask & HEAP_COMBOCID)
return GetRealCmax(cid);
else
return cid;
}
/*
* Given a tuple we are about to delete, determine the correct value to store
* into its t_cid field.
*
* If we don't need a combo CID, *cmax is unchanged and *iscombo is set to
* FALSE. If we do need one, *cmax is replaced by a combo CID and *iscombo
* is set to TRUE.
*
* The reason this is separate from the actual HeapTupleHeaderSetCmax()
* operation is that this could fail due to out-of-memory conditions. Hence
* we need to do this before entering the critical section that actually
* changes the tuple in shared buffers.
*/
void
HeapTupleHeaderAdjustCmax(HeapTupleHeader tup,
CommandId *cmax,
bool *iscombo)
{
/*
* If we're marking a tuple deleted that was inserted by (any
* subtransaction of) our transaction, we need to use a combo command id.
* Test for HeapTupleHeaderXminCommitted() first, because it's cheaper than a
* TransactionIdIsCurrentTransactionId call.
*/
if (!HeapTupleHeaderXminCommitted(tup) &&
TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmin(tup)))
{
CommandId cmin = HeapTupleHeaderGetCmin(tup);
*cmax = GetComboCommandId(cmin, *cmax);
*iscombo = true;
}
else
{
*iscombo = false;
}
}
/*
* HeapTupleSatisfiesMVCC
* True iff heap tuple is valid for the given MVCC snapshot.
*
* Here, we consider the effects of:
* all transactions committed as of the time of the given snapshot
* previous commands of this transaction
*
* Does _not_ include:
* transactions shown as in-progress by the snapshot
* transactions started after the snapshot was taken
* changes made by the current command
*
* (Notice, however, that the tuple status hint bits will be updated on the
* basis of the true state of the transaction, even if we then pretend we
* can't see it.)
*/
bool
HeapTupleSatisfiesMVCC(HeapTuple htup, Snapshot snapshot,
Buffer buffer)
{
HeapTupleHeader tuple = htup->t_data;
Assert(ItemPointerIsValid(&htup->t_self));
Assert(htup->t_tableOid != InvalidOid);
if (!HeapTupleHeaderXminCommitted(tuple))
{
if (HeapTupleHeaderXminInvalid(tuple))
return false;
/* Used by pre-9.0 binary upgrades */
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= snapshot->curcid)
return false; /* inserted after scan started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask)) /* not deleter */
return true;
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
/* updating subtransaction must have aborted */
if (!TransactionIdIsCurrentTransactionId(xmax))
return true;
else if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* updated after scan started */
else
return false; /* updated before scan started */
}
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmin(tuple)))
return false;
else if (TransactionIdDidCommit(HeapTupleHeaderGetRawXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetRawXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
/*
* By here, the inserting transaction has committed - have to check
* when...
*/
if (!HeapTupleHeaderXminFrozen(tuple)
&& XidInMVCCSnapshot(HeapTupleHeaderGetRawXmin(tuple), snapshot))
return false; /* treat as still in progress */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return true;
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
/* already checked above */
Assert(!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask));
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
if (TransactionIdIsCurrentTransactionId(xmax))
{
if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
if (TransactionIdIsInProgress(xmax))
return true;
if (TransactionIdDidCommit(xmax))
{
/* updating transaction committed, but when? */
if (XidInMVCCSnapshot(xmax, snapshot))
return true; /* treat as still in progress */
return false;
}
/* it must have aborted or crashed */
return true;
}
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
return true;
if (!TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
/* xmax transaction committed */
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetRawXmax(tuple));
}
/*
* OK, the deleting transaction committed too ... but when?
*/
if (XidInMVCCSnapshot(HeapTupleHeaderGetRawXmax(tuple), snapshot))
return true; /* treat as still in progress */
return false;
}
/*
* HeapTupleSatisfiesUpdate
*
* Same logic as HeapTupleSatisfiesNow, but returns a more detailed result
* code, since UPDATE needs to know more than "is it visible?". Also,
* tuples of my own xact are tested against the passed CommandId not
* CurrentCommandId.
*
* The possible return codes are:
*
* HeapTupleInvisible: the tuple didn't exist at all when the scan started,
* e.g. it was created by a later CommandId.
*
* HeapTupleMayBeUpdated: The tuple is valid and visible, so it may be
* updated.
*
* HeapTupleSelfUpdated: The tuple was updated by the current transaction,
* after the current scan started.
*
* HeapTupleUpdated: The tuple was updated by a committed transaction.
*
* HeapTupleBeingUpdated: The tuple is being updated by an in-progress
* transaction other than the current transaction. (Note: this includes
* the case where the tuple is share-locked by a MultiXact, even if the
* MultiXact includes the current transaction. Callers that want to
* distinguish that case must test for it themselves.)
*/
HTSU_Result
HeapTupleSatisfiesUpdate(HeapTupleHeader tuple, CommandId curcid,
Buffer buffer)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return HeapTupleInvisible;
/* Used by pre-9.0 binary upgrades */
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HeapTupleInvisible;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return HeapTupleInvisible;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= curcid)
return HeapTupleInvisible; /* inserted after scan started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return HeapTupleMayBeUpdated;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask)) /* not deleter */
return HeapTupleMayBeUpdated;
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
xmax = HeapTupleGetUpdateXid(tuple);
if (!TransactionIdIsValid(xmax))
return HeapTupleMayBeUpdated;
/* updating subtransaction must have aborted */
if (!TransactionIdIsCurrentTransactionId(xmax))
return HeapTupleMayBeUpdated;
else
{
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan
* started */
else
return HeapTupleInvisible; /* updated before scan
* started */
}
}
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
return HeapTupleInvisible;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return HeapTupleMayBeUpdated;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return HeapTupleMayBeUpdated;
return HeapTupleUpdated; /* updated by other */
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
/*
* If it's only locked but neither EXCL_LOCK nor KEYSHR_LOCK is
* set, it cannot possibly be running. Otherwise need to check.
*/
if ((tuple->t_infomask & (HEAP_XMAX_EXCL_LOCK |
HEAP_XMAX_KEYSHR_LOCK)) &&
MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
return HeapTupleBeingUpdated;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
xmax = HeapTupleGetUpdateXid(tuple);
if (!TransactionIdIsValid(xmax))
{
if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
return HeapTupleBeingUpdated;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
if (TransactionIdIsCurrentTransactionId(xmax))
{
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
return HeapTupleBeingUpdated;
if (TransactionIdDidCommit(xmax))
return HeapTupleUpdated;
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return HeapTupleMayBeUpdated;
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
return HeapTupleBeingUpdated;
if (!TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
/* xmax transaction committed */
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetRawXmax(tuple));
return HeapTupleUpdated; /* updated by other */
}
/*
* HeapTupleSatisfiesUpdate
*
* This function returns a more detailed result code than most of the
* functions in this file, since UPDATE needs to know more than "is it
* visible?". It also allows for user-supplied CommandId rather than
* relying on CurrentCommandId.
*
* The possible return codes are:
*
* HeapTupleInvisible: the tuple didn't exist at all when the scan started,
* e.g. it was created by a later CommandId.
*
* HeapTupleMayBeUpdated: The tuple is valid and visible, so it may be
* updated.
*
* HeapTupleSelfUpdated: The tuple was updated by the current transaction,
* after the current scan started.
*
* HeapTupleUpdated: The tuple was updated by a committed transaction.
*
* HeapTupleBeingUpdated: The tuple is being updated by an in-progress
* transaction other than the current transaction. (Note: this includes
* the case where the tuple is share-locked by a MultiXact, even if the
* MultiXact includes the current transaction. Callers that want to
* distinguish that case must test for it themselves.)
*/
HTSU_Result
HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
Buffer buffer)
{
HeapTupleHeader tuple = htup->t_data;
Assert(ItemPointerIsValid(&htup->t_self));
Assert(htup->t_tableOid != InvalidOid);
if (!HeapTupleHeaderXminCommitted(tuple))
{
if (HeapTupleHeaderXminInvalid(tuple))
return HeapTupleInvisible;
/* Used by pre-9.0 binary upgrades */
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HeapTupleInvisible;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return HeapTupleInvisible;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= curcid)
return HeapTupleInvisible; /* inserted after scan started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return HeapTupleMayBeUpdated;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
TransactionId xmax;
xmax = HeapTupleHeaderGetRawXmax(tuple);
/*
* Careful here: even though this tuple was created by our own
* transaction, it might be locked by other transactions, if
* the original version was key-share locked when we updated
* it.
*/
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
if (MultiXactHasRunningRemoteMembers(xmax))
return HeapTupleBeingUpdated;
else
return HeapTupleMayBeUpdated;
}
/* if locker is gone, all's well */
if (!TransactionIdIsInProgress(xmax))
return HeapTupleMayBeUpdated;
if (!TransactionIdIsCurrentTransactionId(xmax))
return HeapTupleBeingUpdated;
else
return HeapTupleMayBeUpdated;
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
/* updating subtransaction must have aborted */
if (!TransactionIdIsCurrentTransactionId(xmax))
{
if (MultiXactHasRunningRemoteMembers(HeapTupleHeaderGetRawXmax(tuple)))
return HeapTupleBeingUpdated;
return HeapTupleMayBeUpdated;
}
else
{
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan
* started */
else
return HeapTupleInvisible; /* updated before scan
* started */
}
}
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmin(tuple)))
return HeapTupleInvisible;
else if (TransactionIdDidCommit(HeapTupleHeaderGetRawXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetRawXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return HeapTupleMayBeUpdated;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return HeapTupleMayBeUpdated;
return HeapTupleUpdated; /* updated by other */
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
/*
* If it's only locked but neither EXCL_LOCK nor KEYSHR_LOCK is
* set, it cannot possibly be running. Otherwise need to check.
*/
if ((tuple->t_infomask & (HEAP_XMAX_EXCL_LOCK |
HEAP_XMAX_KEYSHR_LOCK)) &&
MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
return HeapTupleBeingUpdated;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
if (TransactionIdIsCurrentTransactionId(xmax))
{
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
if (TransactionIdIsInProgress(xmax))
return HeapTupleBeingUpdated;
if (TransactionIdDidCommit(xmax))
return HeapTupleUpdated;
/*
* By here, the update in the Xmax is either aborted or crashed, but
* what about the other members?
*/
if (!MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
{
/*
* There's no member, even just a locker, alive anymore, so we can
* mark the Xmax as invalid.
*/
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
else
{
/* There are lockers running */
return HeapTupleBeingUpdated;
}
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return HeapTupleMayBeUpdated;
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
return HeapTupleBeingUpdated;
if (!TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
/* xmax transaction committed */
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetRawXmax(tuple));
return HeapTupleUpdated; /* updated by other */
}
/*
* HeapTupleSatisfiesDirty
* True iff heap tuple is valid including effects of open transactions.
*
* Here, we consider the effects of:
* all committed and in-progress transactions (as of the current instant)
* previous commands of this transaction
* changes made by the current command
*
* This is essentially like HeapTupleSatisfiesSelf as far as effects of
* the current transaction and committed/aborted xacts are concerned.
* However, we also include the effects of other xacts still in progress.
*
* A special hack is that the passed-in snapshot struct is used as an
* output argument to return the xids of concurrent xacts that affected the
* tuple. snapshot->xmin is set to the tuple's xmin if that is another
* transaction that's still in progress; or to InvalidTransactionId if the
* tuple's xmin is committed good, committed dead, or my own xact. Similarly
* for snapshot->xmax and the tuple's xmax.
*/
bool
HeapTupleSatisfiesDirty(HeapTuple htup, Snapshot snapshot,
Buffer buffer)
{
HeapTupleHeader tuple = htup->t_data;
Assert(ItemPointerIsValid(&htup->t_self));
Assert(htup->t_tableOid != InvalidOid);
snapshot->xmin = snapshot->xmax = InvalidTransactionId;
if (!HeapTupleHeaderXminCommitted(tuple))
{
if (HeapTupleHeaderXminInvalid(tuple))
return false;
/* Used by pre-9.0 binary upgrades */
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmin(tuple)))
{
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask)) /* not deleter */
return true;
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
/* updating subtransaction must have aborted */
if (!TransactionIdIsCurrentTransactionId(xmax))
return true;
else
return false;
}
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
return false;
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmin(tuple)))
{
snapshot->xmin = HeapTupleHeaderGetRawXmin(tuple);
/* XXX shouldn't we fall through to look at xmax? */
return true; /* in insertion by other */
}
else if (TransactionIdDidCommit(HeapTupleHeaderGetRawXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetRawXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return true;
return false; /* updated by other */
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return true;
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
if (TransactionIdIsCurrentTransactionId(xmax))
return false;
if (TransactionIdIsInProgress(xmax))
{
snapshot->xmax = xmax;
return true;
}
if (TransactionIdDidCommit(xmax))
return false;
/* it must have aborted or crashed */
return true;
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return true;
return false;
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
{
if (!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
snapshot->xmax = HeapTupleHeaderGetRawXmax(tuple);
return true;
}
if (!TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
/* xmax transaction committed */
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetRawXmax(tuple));
return false; /* updated by other */
}
/*
* HeapTupleSatisfiesUpdate
*
* Same logic as HeapTupleSatisfiesNow, but returns a more detailed result
* code, since UPDATE needs to know more than "is it visible?". Also,
* tuples of my own xact are tested against the passed CommandId not
* CurrentCommandId.
*/
int
HeapTupleSatisfiesUpdate(HeapTupleHeader tuple, CommandId curcid)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return HeapTupleInvisible;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HeapTupleInvisible;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return HeapTupleInvisible;
}
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return HeapTupleInvisible;
if (TransactionIdDidCommit(xvac))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return HeapTupleInvisible;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= curcid)
return HeapTupleInvisible; /* inserted after scan
* started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return HeapTupleMayBeUpdated;
Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return HeapTupleMayBeUpdated;
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan
* started */
else
return HeapTupleInvisible; /* updated before scan
* started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
return HeapTupleInvisible;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMIN_INVALID;
return HeapTupleInvisible;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return HeapTupleMayBeUpdated;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return HeapTupleMayBeUpdated;
return HeapTupleUpdated; /* updated by other */
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return HeapTupleMayBeUpdated;
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan
* started */
else
return HeapTupleInvisible; /* updated before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return HeapTupleBeingUpdated;
if (!TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMAX_INVALID;
return HeapTupleMayBeUpdated;
}
/* xmax transaction committed */
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
{
tuple->t_infomask |= HEAP_XMAX_INVALID;
return HeapTupleMayBeUpdated;
}
tuple->t_infomask |= HEAP_XMAX_COMMITTED;
return HeapTupleUpdated; /* updated by other */
}
Datum
funny_dup17(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
TransactionId *xid;
int *level;
bool *recursion;
Relation rel;
TupleDesc tupdesc;
HeapTuple tuple;
char *query,
*fieldval,
*fieldtype;
char *when;
int inserted;
int selected = 0;
int ret;
if (!CALLED_AS_TRIGGER(fcinfo))
elog(ERROR, "funny_dup17: not fired by trigger manager");
tuple = trigdata->tg_trigtuple;
rel = trigdata->tg_relation;
tupdesc = rel->rd_att;
if (TRIGGER_FIRED_BEFORE(trigdata->tg_event))
{
xid = &fd17b_xid;
level = &fd17b_level;
recursion = &fd17b_recursion;
when = "BEFORE";
}
else
{
xid = &fd17a_xid;
level = &fd17a_level;
recursion = &fd17a_recursion;
when = "AFTER ";
}
if (!TransactionIdIsCurrentTransactionId(*xid))
{
*xid = GetCurrentTransactionId();
*level = 0;
*recursion = true;
}
if (*level == 17)
{
*recursion = false;
return PointerGetDatum(tuple);
}
if (!(*recursion))
return PointerGetDatum(tuple);
(*level)++;
SPI_connect();
fieldval = SPI_getvalue(tuple, tupdesc, 1);
fieldtype = SPI_gettype(tupdesc, 1);
query = (char *) palloc(100 + NAMEDATALEN * 3 +
strlen(fieldval) + strlen(fieldtype));
sprintf(query, "insert into %s select * from %s where %s = '%s'::%s",
SPI_getrelname(rel), SPI_getrelname(rel),
SPI_fname(tupdesc, 1),
fieldval, fieldtype);
if ((ret = SPI_exec(query, 0)) < 0)
elog(ERROR, "funny_dup17 (fired %s) on level %3d: SPI_exec (insert ...) returned %d",
when, *level, ret);
inserted = SPI_processed;
sprintf(query, "select count (*) from %s where %s = '%s'::%s",
SPI_getrelname(rel),
SPI_fname(tupdesc, 1),
fieldval, fieldtype);
if ((ret = SPI_exec(query, 0)) < 0)
elog(ERROR, "funny_dup17 (fired %s) on level %3d: SPI_exec (select ...) returned %d",
when, *level, ret);
if (SPI_processed > 0)
{
selected = DatumGetInt32(DirectFunctionCall1(int4in,
CStringGetDatum(SPI_getvalue(
SPI_tuptable->vals[0],
SPI_tuptable->tupdesc,
1
))));
}
elog(DEBUG4, "funny_dup17 (fired %s) on level %3d: %d/%d tuples inserted/selected",
when, *level, inserted, selected);
SPI_finish();
(*level)--;
if (*level == 0)
*xid = InvalidTransactionId;
return PointerGetDatum(tuple);
}
/*
* HeapTupleSatisfiesMVCC
* True iff heap tuple is valid for the given MVCC snapshot.
*
* Here, we consider the effects of:
* all transactions committed as of the time of the given snapshot
* previous commands of this transaction
*
* Does _not_ include:
* transactions shown as in-progress by the snapshot
* transactions started after the snapshot was taken
* changes made by the current command
*
* This is the same as HeapTupleSatisfiesNow, except that transactions that
* were in progress or as yet unstarted when the snapshot was taken will
* be treated as uncommitted, even if they have committed by now.
*
* (Notice, however, that the tuple status hint bits will be updated on the
* basis of the true state of the transaction, even if we then pretend we
* can't see it.)
*/
bool
HeapTupleSatisfiesMVCC(HeapTupleHeader tuple, Snapshot snapshot,
Buffer buffer)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= snapshot->curcid)
return false; /* inserted after scan started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
if (tuple->t_infomask & HEAP_IS_LOCKED) /* not deleter */
return true;
Assert(!(tuple->t_infomask & HEAP_XMAX_IS_MULTI));
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
return false;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
/*
* By here, the inserting transaction has committed - have to check
* when...
*/
if (XidInMVCCSnapshot(HeapTupleHeaderGetXmin(tuple), snapshot))
return false; /* treat as still in progress */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (tuple->t_infomask & HEAP_IS_LOCKED)
return true;
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
/* MultiXacts are currently only allowed to lock tuples */
Assert(tuple->t_infomask & HEAP_IS_LOCKED);
return true;
}
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return true;
if (!TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
/* xmax transaction committed */
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetXmax(tuple));
}
/*
* OK, the deleting transaction committed too ... but when?
*/
if (XidInMVCCSnapshot(HeapTupleHeaderGetXmax(tuple), snapshot))
return true; /* treat as still in progress */
return false;
}
/*
* HeapTupleSatisfiesSnapshot
* True iff heap tuple is valid for the given snapshot.
*
* Here, we consider the effects of:
* all transactions committed as of the time of the given snapshot
* previous commands of this transaction
*
* Does _not_ include:
* transactions shown as in-progress by the snapshot
* transactions started after the snapshot was taken
* changes made by the current command
*
* This is the same as HeapTupleSatisfiesNow, except that transactions that
* were in progress or as yet unstarted when the snapshot was taken will
* be treated as uncommitted, even if they have committed by now.
*
* (Notice, however, that the tuple status hint bits will be updated on the
* basis of the true state of the transaction, even if we then pretend we
* can't see it.)
*/
bool
HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= snapshot->curcid)
return false; /* inserted after scan started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
return false;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
}
/*
* By here, the inserting transaction has committed - have to check
* when...
*/
if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmin(tuple),
snapshot->xmin))
{
uint32 i;
if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmin(tuple),
snapshot->xmax))
return false;
for (i = 0; i < snapshot->xcnt; i++)
{
if (TransactionIdEquals(HeapTupleHeaderGetXmin(tuple),
snapshot->xip[i]))
return false;
}
}
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
if (HeapTupleHeaderGetCmax(tuple) >= snapshot->curcid)
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return true;
if (!TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMAX_INVALID;
return true;
}
/* xmax transaction committed */
tuple->t_infomask |= HEAP_XMAX_COMMITTED;
}
/*
* OK, the deleting transaction committed too ... but when?
*/
if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmax(tuple), snapshot->xmin))
{
uint32 i;
if (TransactionIdFollowsOrEquals(HeapTupleHeaderGetXmax(tuple),
snapshot->xmax))
return true;
for (i = 0; i < snapshot->xcnt; i++)
{
if (TransactionIdEquals(HeapTupleHeaderGetXmax(tuple), snapshot->xip[i]))
return true;
}
}
return false;
}
/*
* HeapTupleSatisfiesUpdate
*
* Same logic as HeapTupleSatisfiesNow, but returns a more detailed result
* code, since UPDATE needs to know more than "is it visible?". Also,
* tuples of my own xact are tested against the passed CommandId not
* CurrentCommandId.
*
* The possible return codes are:
*
* HeapTupleInvisible: the tuple didn't exist at all when the scan started,
* e.g. it was created by a later CommandId.
*
* HeapTupleMayBeUpdated: The tuple is valid and visible, so it may be
* updated.
*
* HeapTupleSelfUpdated: The tuple was updated by the current transaction,
* after the current scan started.
*
* HeapTupleUpdated: The tuple was updated by a committed transaction.
*
* HeapTupleBeingUpdated: The tuple is being updated by an in-progress
* transaction other than the current transaction. (Note: this includes
* the case where the tuple is share-locked by a MultiXact, even if the
* MultiXact includes the current transaction. Callers that want to
* distinguish that case must test for it themselves.)
*/
HTSU_Result
HeapTupleSatisfiesUpdate(HeapTupleHeader tuple, CommandId curcid,
Buffer buffer)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return HeapTupleInvisible;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HeapTupleInvisible;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return HeapTupleInvisible;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= curcid)
return HeapTupleInvisible; /* inserted after scan started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return HeapTupleMayBeUpdated;
if (tuple->t_infomask & HEAP_IS_LOCKED) /* not deleter */
return HeapTupleMayBeUpdated;
Assert(!(tuple->t_infomask & HEAP_XMAX_IS_MULTI));
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
return HeapTupleInvisible;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HeapTupleInvisible;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return HeapTupleMayBeUpdated;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (tuple->t_infomask & HEAP_IS_LOCKED)
return HeapTupleMayBeUpdated;
return HeapTupleUpdated; /* updated by other */
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
/* MultiXacts are currently only allowed to lock tuples */
Assert(tuple->t_infomask & HEAP_IS_LOCKED);
if (MultiXactIdIsRunning(HeapTupleHeaderGetXmax(tuple)))
return HeapTupleBeingUpdated;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
if (tuple->t_infomask & HEAP_IS_LOCKED)
return HeapTupleMayBeUpdated;
if (HeapTupleHeaderGetCmax(tuple) >= curcid)
return HeapTupleSelfUpdated; /* updated after scan started */
else
return HeapTupleInvisible; /* updated before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return HeapTupleBeingUpdated;
if (!TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
/* xmax transaction committed */
if (tuple->t_infomask & HEAP_IS_LOCKED)
{
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HeapTupleMayBeUpdated;
}
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetXmax(tuple));
return HeapTupleUpdated; /* updated by other */
}
/*
* HeapTupleSatisfiesDirty
* True iff heap tuple is valid including effects of open transactions.
*
* Here, we consider the effects of:
* all committed and in-progress transactions (as of the current instant)
* previous commands of this transaction
* changes made by the current command
*
* This is essentially like HeapTupleSatisfiesSelf as far as effects of
* the current transaction and committed/aborted xacts are concerned.
* However, we also include the effects of other xacts still in progress.
*
* A special hack is that the passed-in snapshot struct is used as an
* output argument to return the xids of concurrent xacts that affected the
* tuple. snapshot->xmin is set to the tuple's xmin if that is another
* transaction that's still in progress; or to InvalidTransactionId if the
* tuple's xmin is committed good, committed dead, or my own xact. Similarly
* for snapshot->xmax and the tuple's xmax.
*/
bool
HeapTupleSatisfiesDirty(HeapTupleHeader tuple, Snapshot snapshot,
Buffer buffer)
{
snapshot->xmin = snapshot->xmax = InvalidTransactionId;
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
if (tuple->t_infomask & HEAP_IS_LOCKED) /* not deleter */
return true;
Assert(!(tuple->t_infomask & HEAP_XMAX_IS_MULTI));
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
return false;
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
{
snapshot->xmin = HeapTupleHeaderGetXmin(tuple);
/* XXX shouldn't we fall through to look at xmax? */
return true; /* in insertion by other */
}
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (tuple->t_infomask & HEAP_IS_LOCKED)
return true;
return false; /* updated by other */
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
/* MultiXacts are currently only allowed to lock tuples */
Assert(tuple->t_infomask & HEAP_IS_LOCKED);
return true;
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
if (tuple->t_infomask & HEAP_IS_LOCKED)
return true;
return false;
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
{
snapshot->xmax = HeapTupleHeaderGetXmax(tuple);
return true;
}
if (!TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
/* xmax transaction committed */
if (tuple->t_infomask & HEAP_IS_LOCKED)
{
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetXmax(tuple));
return false; /* updated by other */
}
/*
* IndexBuildHeapScan - scan the heap relation to find tuples to be indexed
*
* This is called back from an access-method-specific index build procedure
* after the AM has done whatever setup it needs. The parent heap relation
* is scanned to find tuples that should be entered into the index. Each
* such tuple is passed to the AM's callback routine, which does the right
* things to add it to the new index. After we return, the AM's index
* build procedure does whatever cleanup is needed; in particular, it should
* close the heap and index relations.
*
* The total count of heap tuples is returned. This is for updating pg_class
* statistics. (It's annoying not to be able to do that here, but we can't
* do it until after the relation is closed.) Note that the index AM itself
* must keep track of the number of index tuples; we don't do so here because
* the AM might reject some of the tuples for its own reasons, such as being
* unable to store NULLs.
*/
double
IndexBuildHeapScan(Relation heapRelation,
Relation indexRelation,
IndexInfo *indexInfo,
IndexBuildCallback callback,
void *callback_state)
{
HeapScanDesc scan;
HeapTuple heapTuple;
TupleDesc heapDescriptor;
Datum attdata[INDEX_MAX_KEYS];
char nulls[INDEX_MAX_KEYS];
double reltuples;
List *predicate;
TupleTable tupleTable;
TupleTableSlot *slot;
EState *estate;
ExprContext *econtext;
Snapshot snapshot;
TransactionId OldestXmin;
/*
* sanity checks
*/
Assert(OidIsValid(indexRelation->rd_rel->relam));
heapDescriptor = RelationGetDescr(heapRelation);
/*
* Need an EState for evaluation of index expressions and
* partial-index predicates.
*/
estate = CreateExecutorState();
econtext = GetPerTupleExprContext(estate);
/*
* If this is a predicate (partial) index, we will need to evaluate
* the predicate using ExecQual, which requires the current tuple to
* be in a slot of a TupleTable. Likewise if there are any
* expressions.
*/
if (indexInfo->ii_Predicate != NIL || indexInfo->ii_Expressions != NIL)
{
tupleTable = ExecCreateTupleTable(1);
slot = ExecAllocTableSlot(tupleTable);
ExecSetSlotDescriptor(slot, heapDescriptor, false);
/* Arrange for econtext's scan tuple to be the tuple under test */
econtext->ecxt_scantuple = slot;
/* Set up execution state for predicate. */
predicate = (List *)
ExecPrepareExpr((Expr *) indexInfo->ii_Predicate,
estate);
}
else
{
tupleTable = NULL;
slot = NULL;
predicate = NIL;
}
/*
* Ok, begin our scan of the base relation. We use SnapshotAny
* because we must retrieve all tuples and do our own time qual
* checks.
*/
if (IsBootstrapProcessingMode())
{
snapshot = SnapshotNow;
OldestXmin = InvalidTransactionId;
}
else
{
snapshot = SnapshotAny;
OldestXmin = GetOldestXmin(heapRelation->rd_rel->relisshared);
}
scan = heap_beginscan(heapRelation, /* relation */
snapshot, /* seeself */
0, /* number of keys */
(ScanKey) NULL); /* scan key */
reltuples = 0;
/*
* Scan all tuples in the base relation.
*/
while ((heapTuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
bool tupleIsAlive;
CHECK_FOR_INTERRUPTS();
if (snapshot == SnapshotAny)
{
/* do our own time qual check */
bool indexIt;
uint16 sv_infomask;
/*
* HeapTupleSatisfiesVacuum may update tuple's hint status
* bits. We could possibly get away with not locking the
* buffer here, since caller should hold ShareLock on the
* relation, but let's be conservative about it.
*/
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
sv_infomask = heapTuple->t_data->t_infomask;
switch (HeapTupleSatisfiesVacuum(heapTuple->t_data, OldestXmin))
{
case HEAPTUPLE_DEAD:
indexIt = false;
tupleIsAlive = false;
break;
case HEAPTUPLE_LIVE:
indexIt = true;
tupleIsAlive = true;
break;
case HEAPTUPLE_RECENTLY_DEAD:
/*
* If tuple is recently deleted then we must index it
* anyway to keep VACUUM from complaining.
*/
indexIt = true;
tupleIsAlive = false;
break;
case HEAPTUPLE_INSERT_IN_PROGRESS:
/*
* Since caller should hold ShareLock or better, we
* should not see any tuples inserted by open
* transactions --- unless it's our own transaction.
* (Consider INSERT followed by CREATE INDEX within a
* transaction.) An exception occurs when reindexing
* a system catalog, because we often release lock on
* system catalogs before committing.
*/
if (!TransactionIdIsCurrentTransactionId(
HeapTupleHeaderGetXmin(heapTuple->t_data))
&& !IsSystemRelation(heapRelation))
elog(ERROR, "concurrent insert in progress");
indexIt = true;
tupleIsAlive = true;
break;
case HEAPTUPLE_DELETE_IN_PROGRESS:
/*
* Since caller should hold ShareLock or better, we
* should not see any tuples deleted by open
* transactions --- unless it's our own transaction.
* (Consider DELETE followed by CREATE INDEX within a
* transaction.) An exception occurs when reindexing
* a system catalog, because we often release lock on
* system catalogs before committing.
*/
if (!TransactionIdIsCurrentTransactionId(
HeapTupleHeaderGetXmax(heapTuple->t_data))
&& !IsSystemRelation(heapRelation))
elog(ERROR, "concurrent delete in progress");
indexIt = true;
tupleIsAlive = false;
break;
default:
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
indexIt = tupleIsAlive = false; /* keep compiler quiet */
break;
}
/* check for hint-bit update by HeapTupleSatisfiesVacuum */
if (sv_infomask != heapTuple->t_data->t_infomask)
SetBufferCommitInfoNeedsSave(scan->rs_cbuf);
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
if (!indexIt)
continue;
}
else
{
/* heap_getnext did the time qual check */
tupleIsAlive = true;
}
reltuples += 1;
MemoryContextReset(econtext->ecxt_per_tuple_memory);
/* Set up for predicate or expression evaluation */
if (slot)
ExecStoreTuple(heapTuple, slot, InvalidBuffer, false);
/*
* In a partial index, discard tuples that don't satisfy the
* predicate. We can also discard recently-dead tuples, since
* VACUUM doesn't complain about tuple count mismatch for partial
* indexes.
*/
if (predicate != NIL)
{
if (!tupleIsAlive)
continue;
if (!ExecQual(predicate, econtext, false))
continue;
}
/*
* For the current heap tuple, extract all the attributes we use
* in this index, and note which are null. This also performs
* evaluation of any expressions needed.
*/
FormIndexDatum(indexInfo,
heapTuple,
heapDescriptor,
estate,
attdata,
nulls);
/*
* You'd think we should go ahead and build the index tuple here,
* but some index AMs want to do further processing on the data
* first. So pass the attdata and nulls arrays, instead.
*/
/* Call the AM's callback routine to process the tuple */
callback(indexRelation, heapTuple, attdata, nulls, tupleIsAlive,
callback_state);
}
heap_endscan(scan);
if (tupleTable)
ExecDropTupleTable(tupleTable, true);
FreeExecutorState(estate);
/* These may have been pointing to the now-gone estate */
indexInfo->ii_ExpressionsState = NIL;
indexInfo->ii_PredicateState = NIL;
return reltuples;
}
/*
* HeapTupleSatisfiesItself
* True iff heap tuple is valid "for itself".
*
* Here, we consider the effects of:
* all committed transactions (as of the current instant)
* previous commands of this transaction
* changes made by the current command
*
* Note:
* Assumes heap tuple is valid.
*
* The satisfaction of "itself" requires the following:
*
* ((Xmin == my-transaction && the row was updated by the current transaction, and
* (Xmax is null it was not deleted
* [|| Xmax != my-transaction)]) [or it was deleted by another transaction]
* ||
*
* (Xmin is committed && the row was modified by a committed transaction, and
* (Xmax is null || the row has not been deleted, or
* (Xmax != my-transaction && the row was deleted by another transaction
* Xmax is not committed))) that has not been committed
*/
bool
HeapTupleSatisfiesItself(HeapTupleHeader tuple)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
return false;
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
return false;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
return false; /* updated by other */
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
return false;
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return true;
if (!TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMAX_INVALID;
return true;
}
/* xmax transaction committed */
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
{
tuple->t_infomask |= HEAP_XMAX_INVALID;
return true;
}
tuple->t_infomask |= HEAP_XMAX_COMMITTED;
return false;
}
/*
* HeapTupleSatisfiesVacuum
*
* Determine the status of tuples for VACUUM purposes. Here, what
* we mainly want to know is if a tuple is potentially visible to *any*
* running transaction. If so, it can't be removed yet by VACUUM.
*
* OldestXmin is a cutoff XID (obtained from GetOldestXmin()). Tuples
* deleted by XIDs >= OldestXmin are deemed "recently dead"; they might
* still be visible to some open transaction, so we can't remove them,
* even if we see that the deleting transaction has committed.
*/
HTSV_Result
HeapTupleSatisfiesVacuum(HeapTupleHeader tuple, TransactionId OldestXmin)
{
/*
* Has inserting transaction committed?
*
* If the inserting transaction aborted, then the tuple was never visible
* to any other transaction, so we can delete it immediately.
*/
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return HEAPTUPLE_DEAD;
else if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HEAPTUPLE_DELETE_IN_PROGRESS;
if (TransactionIdIsInProgress(xvac))
return HEAPTUPLE_DELETE_IN_PROGRESS;
if (TransactionIdDidCommit(xvac))
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return HEAPTUPLE_DEAD;
}
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HEAPTUPLE_INSERT_IN_PROGRESS;
if (TransactionIdIsInProgress(xvac))
return HEAPTUPLE_INSERT_IN_PROGRESS;
if (TransactionIdDidCommit(xvac))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return HEAPTUPLE_DEAD;
}
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
{
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return HEAPTUPLE_INSERT_IN_PROGRESS;
Assert(HeapTupleHeaderGetXmin(tuple) ==
HeapTupleHeaderGetXmax(tuple));
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return HEAPTUPLE_INSERT_IN_PROGRESS;
/* inserted and then deleted by same xact */
return HEAPTUPLE_DELETE_IN_PROGRESS;
}
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
/*
* Not in Progress, Not Committed, so either Aborted or
* crashed
*/
tuple->t_infomask |= HEAP_XMIN_INVALID;
return HEAPTUPLE_DEAD;
}
/* Should only get here if we set XMIN_COMMITTED */
Assert(tuple->t_infomask & HEAP_XMIN_COMMITTED);
}
/*
* Okay, the inserter committed, so it was good at some point. Now
* what about the deleting transaction?
*/
if (tuple->t_infomask & HEAP_XMAX_INVALID)
return HEAPTUPLE_LIVE;
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
{
/*
* "Deleting" xact really only marked it for update, so the tuple
* is live in any case. However, we must make sure that either
* XMAX_COMMITTED or XMAX_INVALID gets set once the xact is gone;
* otherwise it is unsafe to recycle CLOG status after vacuuming.
*/
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return HEAPTUPLE_LIVE;
/*
* We don't really care whether xmax did commit, abort or
* crash. We know that xmax did mark the tuple for update, but
* it did not and will never actually update it.
*/
tuple->t_infomask |= HEAP_XMAX_INVALID;
}
return HEAPTUPLE_LIVE;
}
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return HEAPTUPLE_DELETE_IN_PROGRESS;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
tuple->t_infomask |= HEAP_XMAX_COMMITTED;
else
{
/*
* Not in Progress, Not Committed, so either Aborted or
* crashed
*/
tuple->t_infomask |= HEAP_XMAX_INVALID;
return HEAPTUPLE_LIVE;
}
/* Should only get here if we set XMAX_COMMITTED */
Assert(tuple->t_infomask & HEAP_XMAX_COMMITTED);
}
/*
* Deleter committed, but check special cases.
*/
if (TransactionIdEquals(HeapTupleHeaderGetXmin(tuple),
HeapTupleHeaderGetXmax(tuple)))
{
/*
* Inserter also deleted it, so it was never visible to anyone
* else. However, we can only remove it early if it's not an
* updated tuple; else its parent tuple is linking to it via t_ctid,
* and this tuple mustn't go away before the parent does.
*/
if (!(tuple->t_infomask & HEAP_UPDATED))
return HEAPTUPLE_DEAD;
}
if (!TransactionIdPrecedes(HeapTupleHeaderGetXmax(tuple), OldestXmin))
{
/* deleting xact is too recent, tuple could still be visible */
return HEAPTUPLE_RECENTLY_DEAD;
}
/* Otherwise, it's dead and removable */
return HEAPTUPLE_DEAD;
}
/*
* HeapTupleSatisfiesNow
* True iff heap tuple is valid "now".
*
* Here, we consider the effects of:
* all committed transactions (as of the current instant)
* previous commands of this transaction
*
* Note we do _not_ include changes made by the current command. This
* solves the "Halloween problem" wherein an UPDATE might try to re-update
* its own output tuples, http://en.wikipedia.org/wiki/Halloween_Problem.
*
* Note:
* Assumes heap tuple is valid.
*
* The satisfaction of "now" requires the following:
*
* ((Xmin == my-transaction && inserted by the current transaction
* Cmin < my-command && before this command, and
* (Xmax is null || the row has not been deleted, or
* (Xmax == my-transaction && it was deleted by the current transaction
* Cmax >= my-command))) but not before this command,
* || or
* (Xmin is committed && the row was inserted by a committed transaction, and
* (Xmax is null || the row has not been deleted, or
* (Xmax == my-transaction && the row is being deleted by this transaction
* Cmax >= my-command) || but it's not deleted "yet", or
* (Xmax != my-transaction && the row was deleted by another transaction
* Xmax is not committed)))) that has not been committed
*
*/
bool
HeapTupleSatisfiesNow(HeapTupleHeader tuple, Snapshot snapshot, Buffer buffer)
{
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
/* Used by pre-9.0 binary upgrades */
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (HeapTupleHeaderGetCmin(tuple) >= GetCurrentCommandId(false))
return false; /* inserted after scan started */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask)) /* not deleter */
return true;
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
xmax = HeapTupleGetUpdateXid(tuple);
if (!TransactionIdIsValid(xmax))
return true;
/* updating subtransaction must have aborted */
if (!TransactionIdIsCurrentTransactionId(xmax))
return true;
else
return false;
}
if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
/* deleting subtransaction must have aborted */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
if (HeapTupleHeaderGetCmax(tuple) >= GetCurrentCommandId(false))
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
return false;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetXmin(tuple));
else
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return false;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return true;
return false;
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return true;
xmax = HeapTupleGetUpdateXid(tuple);
if (!TransactionIdIsValid(xmax))
return true;
if (TransactionIdIsCurrentTransactionId(xmax))
{
if (HeapTupleHeaderGetCmax(tuple) >= GetCurrentCommandId(false))
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
if (TransactionIdIsInProgress(xmax))
return true;
if (TransactionIdDidCommit(xmax))
return false;
return true;
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return true;
if (HeapTupleHeaderGetCmax(tuple) >= GetCurrentCommandId(false))
return true; /* deleted after scan started */
else
return false; /* deleted before scan started */
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
return true;
if (!TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
{
/* it must have aborted or crashed */
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
/* xmax transaction committed */
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return true;
}
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetRawXmax(tuple));
return false;
}
/*
* HeapTupleSatisfiesVacuum
*
* Determine the status of tuples for VACUUM purposes. Here, what
* we mainly want to know is if a tuple is potentially visible to *any*
* running transaction. If so, it can't be removed yet by VACUUM.
*
* OldestXmin is a cutoff XID (obtained from GetOldestXmin()). Tuples
* deleted by XIDs >= OldestXmin are deemed "recently dead"; they might
* still be visible to some open transaction, so we can't remove them,
* even if we see that the deleting transaction has committed.
*/
HTSV_Result
HeapTupleSatisfiesVacuum(HeapTuple htup, TransactionId OldestXmin,
Buffer buffer)
{
HeapTupleHeader tuple = htup->t_data;
Assert(ItemPointerIsValid(&htup->t_self));
Assert(htup->t_tableOid != InvalidOid);
/*
* Has inserting transaction committed?
*
* If the inserting transaction aborted, then the tuple was never visible
* to any other transaction, so we can delete it immediately.
*/
if (!HeapTupleHeaderXminCommitted(tuple))
{
if (HeapTupleHeaderXminInvalid(tuple))
return HEAPTUPLE_DEAD;
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HEAPTUPLE_DELETE_IN_PROGRESS;
if (TransactionIdIsInProgress(xvac))
return HEAPTUPLE_DELETE_IN_PROGRESS;
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HEAPTUPLE_DEAD;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
/* Used by pre-9.0 binary upgrades */
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HEAPTUPLE_INSERT_IN_PROGRESS;
if (TransactionIdIsInProgress(xvac))
return HEAPTUPLE_INSERT_IN_PROGRESS;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HEAPTUPLE_DEAD;
}
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmin(tuple)))
{
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return HEAPTUPLE_INSERT_IN_PROGRESS;
/* only locked? run infomask-only check first, for performance */
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask) ||
HeapTupleHeaderIsOnlyLocked(tuple))
return HEAPTUPLE_INSERT_IN_PROGRESS;
/* inserted and then deleted by same xact */
return HEAPTUPLE_DELETE_IN_PROGRESS;
}
else if (TransactionIdDidCommit(HeapTupleHeaderGetRawXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetRawXmin(tuple));
else
{
/*
* Not in Progress, Not Committed, so either Aborted or crashed
*/
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HEAPTUPLE_DEAD;
}
/*
* At this point the xmin is known committed, but we might not have
* been able to set the hint bit yet; so we can no longer Assert that
* it's set.
*/
}
/*
* Okay, the inserter committed, so it was good at some point. Now what
* about the deleting transaction?
*/
if (tuple->t_infomask & HEAP_XMAX_INVALID)
return HEAPTUPLE_LIVE;
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
{
/*
* "Deleting" xact really only locked it, so the tuple is live in any
* case. However, we should make sure that either XMAX_COMMITTED or
* XMAX_INVALID gets set once the xact is gone, to reduce the costs of
* examining the tuple for future xacts. Also, marking dead
* MultiXacts as invalid here provides defense against MultiXactId
* wraparound (see also comments in heap_freeze_tuple()).
*/
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
/*
* If it's only locked but neither EXCL_LOCK nor KEYSHR_LOCK
* are set, it cannot possibly be running; otherwise have to
* check.
*/
if ((tuple->t_infomask & (HEAP_XMAX_EXCL_LOCK |
HEAP_XMAX_KEYSHR_LOCK)) &&
MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
return HEAPTUPLE_LIVE;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
}
else
{
if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
return HEAPTUPLE_LIVE;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
}
}
/*
* We don't really care whether xmax did commit, abort or crash. We
* know that xmax did lock the tuple, but it did not and will never
* actually update it.
*/
return HEAPTUPLE_LIVE;
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId xmax;
if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
{
/* already checked above */
Assert(!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask));
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
if (TransactionIdIsInProgress(xmax))
return HEAPTUPLE_DELETE_IN_PROGRESS;
else if (TransactionIdDidCommit(xmax))
/* there are still lockers around -- can't return DEAD here */
return HEAPTUPLE_RECENTLY_DEAD;
/* updating transaction aborted */
return HEAPTUPLE_LIVE;
}
Assert(!(tuple->t_infomask & HEAP_XMAX_COMMITTED));
xmax = HeapTupleGetUpdateXid(tuple);
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
/* multi is not running -- updating xact cannot be */
Assert(!TransactionIdIsInProgress(xmax));
if (TransactionIdDidCommit(xmax))
{
if (!TransactionIdPrecedes(xmax, OldestXmin))
return HEAPTUPLE_RECENTLY_DEAD;
else
return HEAPTUPLE_DEAD;
}
/*
* Not in Progress, Not Committed, so either Aborted or crashed.
* Remove the Xmax.
*/
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
return HEAPTUPLE_LIVE;
}
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
return HEAPTUPLE_DELETE_IN_PROGRESS;
else if (TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetRawXmax(tuple));
else
{
/*
* Not in Progress, Not Committed, so either Aborted or crashed
*/
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HEAPTUPLE_LIVE;
}
/*
* At this point the xmax is known committed, but we might not have
* been able to set the hint bit yet; so we can no longer Assert that
* it's set.
*/
}
/*
* Deleter committed, but perhaps it was recent enough that some open
* transactions could still see the tuple.
*/
if (!TransactionIdPrecedes(HeapTupleHeaderGetRawXmax(tuple), OldestXmin))
return HEAPTUPLE_RECENTLY_DEAD;
/* Otherwise, it's dead and removable */
return HEAPTUPLE_DEAD;
}
/*
* HeapTupleSatisfiesVacuum
*
* Determine the status of tuples for VACUUM purposes. Here, what
* we mainly want to know is if a tuple is potentially visible to *any*
* running transaction. If so, it can't be removed yet by VACUUM.
*
* OldestXmin is a cutoff XID (obtained from GetOldestXmin()). Tuples
* deleted by XIDs >= OldestXmin are deemed "recently dead"; they might
* still be visible to some open transaction, so we can't remove them,
* even if we see that the deleting transaction has committed.
*/
HTSV_Result
HeapTupleSatisfiesVacuum(HeapTupleHeader tuple, TransactionId OldestXmin,
Buffer buffer)
{
/*
* Has inserting transaction committed?
*
* If the inserting transaction aborted, then the tuple was never visible
* to any other transaction, so we can delete it immediately.
*/
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return HEAPTUPLE_DEAD;
else if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HEAPTUPLE_DELETE_IN_PROGRESS;
if (TransactionIdIsInProgress(xvac))
return HEAPTUPLE_DELETE_IN_PROGRESS;
if (TransactionIdDidCommit(xvac))
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HEAPTUPLE_DEAD;
}
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return HEAPTUPLE_INSERT_IN_PROGRESS;
if (TransactionIdIsInProgress(xvac))
return HEAPTUPLE_INSERT_IN_PROGRESS;
if (TransactionIdDidCommit(xvac))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
InvalidTransactionId);
else
{
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HEAPTUPLE_DEAD;
}
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
{
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return HEAPTUPLE_INSERT_IN_PROGRESS;
if (tuple->t_infomask & HEAP_IS_LOCKED)
return HEAPTUPLE_INSERT_IN_PROGRESS;
/* inserted and then deleted by same xact */
return HEAPTUPLE_DELETE_IN_PROGRESS;
}
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
HeapTupleHeaderGetXmin(tuple));
else
{
/*
* Not in Progress, Not Committed, so either Aborted or crashed
*/
SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
InvalidTransactionId);
return HEAPTUPLE_DEAD;
}
/*
* At this point the xmin is known committed, but we might not have
* been able to set the hint bit yet; so we can no longer Assert that
* it's set.
*/
}
/*
* Okay, the inserter committed, so it was good at some point. Now what
* about the deleting transaction?
*/
if (tuple->t_infomask & HEAP_XMAX_INVALID)
return HEAPTUPLE_LIVE;
if (tuple->t_infomask & HEAP_IS_LOCKED)
{
/*
* "Deleting" xact really only locked it, so the tuple is live in any
* case. However, we should make sure that either XMAX_COMMITTED or
* XMAX_INVALID gets set once the xact is gone, to reduce the costs of
* examining the tuple for future xacts. Also, marking dead
* MultiXacts as invalid here provides defense against MultiXactId
* wraparound (see also comments in heap_freeze_tuple()).
*/
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
if (MultiXactIdIsRunning(HeapTupleHeaderGetXmax(tuple)))
return HEAPTUPLE_LIVE;
}
else
{
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return HEAPTUPLE_LIVE;
}
/*
* We don't really care whether xmax did commit, abort or crash.
* We know that xmax did lock the tuple, but it did not and will
* never actually update it.
*/
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
}
return HEAPTUPLE_LIVE;
}
if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
{
/* MultiXacts are currently only allowed to lock tuples */
Assert(tuple->t_infomask & HEAP_IS_LOCKED);
return HEAPTUPLE_LIVE;
}
if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
{
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
return HEAPTUPLE_DELETE_IN_PROGRESS;
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetXmax(tuple));
else
{
/*
* Not in Progress, Not Committed, so either Aborted or crashed
*/
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
InvalidTransactionId);
return HEAPTUPLE_LIVE;
}
/*
* At this point the xmax is known committed, but we might not have
* been able to set the hint bit yet; so we can no longer Assert that
* it's set.
*/
}
/*
* Deleter committed, but check special cases.
*/
if (TransactionIdEquals(HeapTupleHeaderGetXmin(tuple),
HeapTupleHeaderGetXmax(tuple)))
{
/*
* Inserter also deleted it, so it was never visible to anyone else.
* However, we can only remove it early if it's not an updated tuple;
* else its parent tuple is linking to it via t_ctid, and this tuple
* mustn't go away before the parent does.
*/
if (!(tuple->t_infomask & HEAP_UPDATED))
return HEAPTUPLE_DEAD;
}
if (!TransactionIdPrecedes(HeapTupleHeaderGetXmax(tuple), OldestXmin))
{
/* deleting xact is too recent, tuple could still be visible */
return HEAPTUPLE_RECENTLY_DEAD;
}
/* Otherwise, it's dead and removable */
return HEAPTUPLE_DEAD;
}
/*
* HeapTupleSatisfiesDirty
* True iff heap tuple is valid including effects of open transactions.
*
* Here, we consider the effects of:
* all committed and in-progress transactions (as of the current instant)
* previous commands of this transaction
* changes made by the current command
*
* This is essentially like HeapTupleSatisfiesItself as far as effects of
* the current transaction and committed/aborted xacts are concerned.
* However, we also include the effects of other xacts still in progress.
*
* Returns extra information in the global variable SnapshotDirty, namely
* xids of concurrent xacts that affected the tuple. Also, the tuple's
* t_ctid (forward link) is returned if it's being updated.
*/
bool
HeapTupleSatisfiesDirty(HeapTupleHeader tuple)
{
SnapshotDirty->xmin = SnapshotDirty->xmax = InvalidTransactionId;
ItemPointerSetInvalid(&(SnapshotDirty->tid));
if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
{
if (tuple->t_infomask & HEAP_XMIN_INVALID)
return false;
if (tuple->t_infomask & HEAP_MOVED_OFF)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (TransactionIdIsCurrentTransactionId(xvac))
return false;
if (!TransactionIdIsInProgress(xvac))
{
if (TransactionIdDidCommit(xvac))
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
}
}
else if (tuple->t_infomask & HEAP_MOVED_IN)
{
TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
if (!TransactionIdIsCurrentTransactionId(xvac))
{
if (TransactionIdIsInProgress(xvac))
return false;
if (TransactionIdDidCommit(xvac))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
}
}
else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
{
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid */
return true;
Assert(TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)));
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
return false;
}
else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
{
SnapshotDirty->xmin = HeapTupleHeaderGetXmin(tuple);
/* XXX shouldn't we fall through to look at xmax? */
return true; /* in insertion by other */
}
else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
tuple->t_infomask |= HEAP_XMIN_COMMITTED;
else
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMIN_INVALID;
return false;
}
}
/* by here, the inserting transaction has committed */
if (tuple->t_infomask & HEAP_XMAX_INVALID) /* xid invalid or aborted */
return true;
if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
{
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
SnapshotDirty->tid = tuple->t_ctid;
return false; /* updated by other */
}
if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmax(tuple)))
{
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
return true;
return false;
}
if (TransactionIdIsInProgress(HeapTupleHeaderGetXmax(tuple)))
{
SnapshotDirty->xmax = HeapTupleHeaderGetXmax(tuple);
return true;
}
if (!TransactionIdDidCommit(HeapTupleHeaderGetXmax(tuple)))
{
/* it must have aborted or crashed */
tuple->t_infomask |= HEAP_XMAX_INVALID;
return true;
}
/* xmax transaction committed */
if (tuple->t_infomask & HEAP_MARKED_FOR_UPDATE)
{
tuple->t_infomask |= HEAP_XMAX_INVALID;
return true;
}
tuple->t_infomask |= HEAP_XMAX_COMMITTED;
SnapshotDirty->tid = tuple->t_ctid;
return false; /* updated by other */
}