#include "postgres.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/multixact.h"
#include "access/tableam.h"
#include "access/transam.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "storage/bufmgr.h"
#include "storage/procarray.h"
#include "utils/builtins.h"
#include "utils/snapmgr.h"

Include dependency graph for heapam_visibility.c:

Functions
static void	SetHintBits (HeapTupleHeader tuple, Buffer buffer, uint16 infomask, TransactionId xid)

void	HeapTupleSetHintBits (HeapTupleHeader tuple, Buffer buffer, uint16 infomask, TransactionId xid)

static bool	HeapTupleCleanMoved (HeapTupleHeader tuple, Buffer buffer)

static bool	HeapTupleSatisfiesSelf (HeapTuple htup, Snapshot snapshot, Buffer buffer)

static bool	HeapTupleSatisfiesAny (HeapTuple htup, Snapshot snapshot, Buffer buffer)

static bool	HeapTupleSatisfiesToast (HeapTuple htup, Snapshot snapshot, Buffer buffer)

TM_Result	HeapTupleSatisfiesUpdate (HeapTuple htup, CommandId curcid, Buffer buffer)

static bool	HeapTupleSatisfiesDirty (HeapTuple htup, Snapshot snapshot, Buffer buffer)

static bool	HeapTupleSatisfiesMVCC (HeapTuple htup, Snapshot snapshot, Buffer buffer)

HTSV_Result	HeapTupleSatisfiesVacuum (HeapTuple htup, TransactionId OldestXmin, Buffer buffer)

HTSV_Result	HeapTupleSatisfiesVacuumHorizon (HeapTuple htup, Buffer buffer, TransactionId *dead_after)

static bool	HeapTupleSatisfiesNonVacuumable (HeapTuple htup, Snapshot snapshot, Buffer buffer)

bool	HeapTupleIsSurelyDead (HeapTuple htup, GlobalVisState *vistest)

bool	HeapTupleHeaderIsOnlyLocked (HeapTupleHeader tuple)

static bool	TransactionIdInArray (TransactionId xid, TransactionId *xip, Size num)

static bool	HeapTupleSatisfiesHistoricMVCC (HeapTuple htup, Snapshot snapshot, Buffer buffer)

bool	HeapTupleSatisfiesVisibility (HeapTuple htup, Snapshot snapshot, Buffer buffer)

Function Documentation

◆ HeapTupleCleanMoved()

static bool HeapTupleCleanMoved	(	HeapTupleHeader	tuple,
		Buffer	buffer
	)

inlinestatic

Definition at line 154 of file heapam_visibility.c.

{
    TransactionId xvac;
 
    /* only used by pre-9.0 binary upgrades */
    if (likely(!(tuple->t_infomask & (HEAP_MOVED_OFF | HEAP_MOVED_IN))))
        return true;
 
    xvac = HeapTupleHeaderGetXvac(tuple);
 
    if (TransactionIdIsCurrentTransactionId(xvac))
        elog(ERROR, "encountered tuple with HEAP_MOVED considered current");
 
    if (TransactionIdIsInProgress(xvac))
        elog(ERROR, "encountered tuple with HEAP_MOVED considered in-progress");
 
    if (tuple->t_infomask & HEAP_MOVED_OFF)
    {
        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)
    {
        if (TransactionIdDidCommit(xvac))
            SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
                        InvalidTransactionId);
        else
        {
            SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
                        InvalidTransactionId);
            return false;
        }
    }
 
    return true;
}

References elog, ERROR, HEAP_MOVED_IN, HEAP_MOVED_OFF, HEAP_XMIN_COMMITTED, HEAP_XMIN_INVALID, HeapTupleHeaderGetXvac(), InvalidTransactionId, likely, SetHintBits(), HeapTupleHeaderData::t_infomask, TransactionIdDidCommit(), TransactionIdIsCurrentTransactionId(), and TransactionIdIsInProgress().

Referenced by HeapTupleSatisfiesDirty(), HeapTupleSatisfiesMVCC(), HeapTupleSatisfiesSelf(), HeapTupleSatisfiesToast(), HeapTupleSatisfiesUpdate(), and HeapTupleSatisfiesVacuumHorizon().

◆ HeapTupleHeaderIsOnlyLocked()

bool HeapTupleHeaderIsOnlyLocked ( HeapTupleHeader tuple )

Definition at line 1358 of file heapam_visibility.c.

{
    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;
}

References Assert(), HEAP_XMAX_INVALID, HEAP_XMAX_IS_MULTI, HEAP_XMAX_LOCK_ONLY, HeapTupleGetUpdateXid(), HeapTupleHeaderGetRawXmax(), HeapTupleHeaderData::t_infomask, TransactionIdDidCommit(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), and TransactionIdIsValid.

Referenced by heap_delete(), heap_get_latest_tid(), heap_lock_tuple(), heap_lock_updated_tuple_rec(), HeapTupleSatisfiesVacuumHorizon(), and rewrite_heap_tuple().

◆ HeapTupleIsSurelyDead()

bool HeapTupleIsSurelyDead	(	HeapTuple	htup,
		GlobalVisState *	vistest
	)

Definition at line 1303 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
 
    /*
     * If the inserting transaction is marked invalid, then it aborted, and
     * the tuple is definitely dead.  If it's marked neither committed nor
     * invalid, then we assume it's still alive (since the presumption is that
     * all relevant hint bits were just set moments ago).
     */
    if (!HeapTupleHeaderXminCommitted(tuple))
        return HeapTupleHeaderXminInvalid(tuple);
 
    /*
     * If the inserting transaction committed, but any deleting transaction
     * aborted, the tuple is still alive.
     */
    if (tuple->t_infomask & HEAP_XMAX_INVALID)
        return false;
 
    /*
     * If the XMAX is just a lock, the tuple is still alive.
     */
    if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
        return false;
 
    /*
     * If the Xmax is a MultiXact, it might be dead or alive, but we cannot
     * know without checking pg_multixact.
     */
    if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
        return false;
 
    /* If deleter isn't known to have committed, assume it's still running. */
    if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
        return false;
 
    /* Deleter committed, so tuple is dead if the XID is old enough. */
    return GlobalVisTestIsRemovableXid(vistest,
                                       HeapTupleHeaderGetRawXmax(tuple));
}

References Assert(), GlobalVisTestIsRemovableXid(), HEAP_XMAX_COMMITTED, HEAP_XMAX_INVALID, HEAP_XMAX_IS_LOCKED_ONLY(), HEAP_XMAX_IS_MULTI, HeapTupleHeaderGetRawXmax(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminInvalid(), InvalidOid, ItemPointerIsValid(), HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, and HeapTupleData::t_tableOid.

Referenced by heap_hot_search_buffer().

◆ HeapTupleSatisfiesAny()

static bool HeapTupleSatisfiesAny	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

static

Definition at line 352 of file heapam_visibility.c.

{
    return true;
}

Referenced by HeapTupleSatisfiesVisibility().

◆ HeapTupleSatisfiesDirty()

static bool HeapTupleSatisfiesDirty	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

static

Definition at line 681 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
 
    snapshot->xmin = snapshot->xmax = InvalidTransactionId;
    snapshot->speculativeToken = 0;
 
    if (!HeapTupleHeaderXminCommitted(tuple))
    {
        if (HeapTupleHeaderXminInvalid(tuple))
            return false;
 
        if (!HeapTupleCleanMoved(tuple, buffer))
            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)))
        {
            /*
             * Return the speculative token to caller.  Caller can worry about
             * xmax, since it requires a conclusively locked row version, and
             * a concurrent update to this tuple is a conflict of its
             * purposes.
             */
            if (HeapTupleHeaderIsSpeculative(tuple))
            {
                snapshot->speculativeToken =
                    HeapTupleHeaderGetSpeculativeToken(tuple);
 
                Assert(snapshot->speculativeToken != 0);
            }
 
            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 */
}

References Assert(), HEAP_XMAX_COMMITTED, HEAP_XMAX_INVALID, HEAP_XMAX_IS_LOCKED_ONLY(), HEAP_XMAX_IS_MULTI, HEAP_XMIN_COMMITTED, HEAP_XMIN_INVALID, HeapTupleCleanMoved(), HeapTupleGetUpdateXid(), HeapTupleHeaderGetRawXmax(), HeapTupleHeaderGetRawXmin(), HeapTupleHeaderGetSpeculativeToken(), HeapTupleHeaderIsSpeculative(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminInvalid(), InvalidOid, InvalidTransactionId, ItemPointerIsValid(), SetHintBits(), SnapshotData::speculativeToken, HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, HeapTupleData::t_tableOid, TransactionIdDidCommit(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), TransactionIdIsValid, SnapshotData::xmax, and SnapshotData::xmin.

Referenced by HeapTupleSatisfiesVisibility().

◆ HeapTupleSatisfiesHistoricMVCC()

static bool HeapTupleSatisfiesHistoricMVCC	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

static

Definition at line 1425 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
    TransactionId xmin = HeapTupleHeaderGetXmin(tuple);
    TransactionId xmax = HeapTupleHeaderGetRawXmax(tuple);
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
 
    /* inserting transaction aborted */
    if (HeapTupleHeaderXminInvalid(tuple))
    {
        Assert(!TransactionIdDidCommit(xmin));
        return false;
    }
    /* check if it's one of our txids, toplevel is also in there */
    else if (TransactionIdInArray(xmin, snapshot->subxip, snapshot->subxcnt))
    {
        bool        resolved;
        CommandId   cmin = HeapTupleHeaderGetRawCommandId(tuple);
        CommandId   cmax = InvalidCommandId;
 
        /*
         * another transaction might have (tried to) delete this tuple or
         * cmin/cmax was stored in a combo CID. So we need to lookup the
         * actual values externally.
         */
        resolved = ResolveCminCmaxDuringDecoding(HistoricSnapshotGetTupleCids(), snapshot,
                                                 htup, buffer,
                                                 &cmin, &cmax);
 
        /*
         * If we haven't resolved the combo CID to cmin/cmax, that means we
         * have not decoded the combo CID yet. That means the cmin is
         * definitely in the future, and we're not supposed to see the tuple
         * yet.
         *
         * XXX This only applies to decoding of in-progress transactions. In
         * regular logical decoding we only execute this code at commit time,
         * at which point we should have seen all relevant combo CIDs. So
         * ideally, we should error out in this case but in practice, this
         * won't happen. If we are too worried about this then we can add an
         * elog inside ResolveCminCmaxDuringDecoding.
         *
         * XXX For the streaming case, we can track the largest combo CID
         * assigned, and error out based on this (when unable to resolve combo
         * CID below that observed maximum value).
         */
        if (!resolved)
            return false;
 
        Assert(cmin != InvalidCommandId);
 
        if (cmin >= snapshot->curcid)
            return false;       /* inserted after scan started */
        /* fall through */
    }
    /* committed before our xmin horizon. Do a normal visibility check. */
    else if (TransactionIdPrecedes(xmin, snapshot->xmin))
    {
        Assert(!(HeapTupleHeaderXminCommitted(tuple) &&
                 !TransactionIdDidCommit(xmin)));
 
        /* check for hint bit first, consult clog afterwards */
        if (!HeapTupleHeaderXminCommitted(tuple) &&
            !TransactionIdDidCommit(xmin))
            return false;
        /* fall through */
    }
    /* beyond our xmax horizon, i.e. invisible */
    else if (TransactionIdFollowsOrEquals(xmin, snapshot->xmax))
    {
        return false;
    }
    /* check if it's a committed transaction in [xmin, xmax) */
    else if (TransactionIdInArray(xmin, snapshot->xip, snapshot->xcnt))
    {
        /* fall through */
    }
 
    /*
     * none of the above, i.e. between [xmin, xmax) but hasn't committed. I.e.
     * invisible.
     */
    else
    {
        return false;
    }
 
    /* at this point we know xmin is visible, go on to check xmax */
 
    /* xid invalid or aborted */
    if (tuple->t_infomask & HEAP_XMAX_INVALID)
        return true;
    /* locked tuples are always visible */
    else if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
        return true;
 
    /*
     * We can see multis here if we're looking at user tables or if somebody
     * SELECT ... FOR SHARE/UPDATE a system table.
     */
    else if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
    {
        xmax = HeapTupleGetUpdateXid(tuple);
    }
 
    /* check if it's one of our txids, toplevel is also in there */
    if (TransactionIdInArray(xmax, snapshot->subxip, snapshot->subxcnt))
    {
        bool        resolved;
        CommandId   cmin;
        CommandId   cmax = HeapTupleHeaderGetRawCommandId(tuple);
 
        /* Lookup actual cmin/cmax values */
        resolved = ResolveCminCmaxDuringDecoding(HistoricSnapshotGetTupleCids(), snapshot,
                                                 htup, buffer,
                                                 &cmin, &cmax);
 
        /*
         * If we haven't resolved the combo CID to cmin/cmax, that means we
         * have not decoded the combo CID yet. That means the cmax is
         * definitely in the future, and we're still supposed to see the
         * tuple.
         *
         * XXX This only applies to decoding of in-progress transactions. In
         * regular logical decoding we only execute this code at commit time,
         * at which point we should have seen all relevant combo CIDs. So
         * ideally, we should error out in this case but in practice, this
         * won't happen. If we are too worried about this then we can add an
         * elog inside ResolveCminCmaxDuringDecoding.
         *
         * XXX For the streaming case, we can track the largest combo CID
         * assigned, and error out based on this (when unable to resolve combo
         * CID below that observed maximum value).
         */
        if (!resolved || cmax == InvalidCommandId)
            return true;
 
        if (cmax >= snapshot->curcid)
            return true;        /* deleted after scan started */
        else
            return false;       /* deleted before scan started */
    }
    /* below xmin horizon, normal transaction state is valid */
    else if (TransactionIdPrecedes(xmax, snapshot->xmin))
    {
        Assert(!(tuple->t_infomask & HEAP_XMAX_COMMITTED &&
                 !TransactionIdDidCommit(xmax)));
 
        /* check hint bit first */
        if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
            return false;
 
        /* check clog */
        return !TransactionIdDidCommit(xmax);
    }
    /* above xmax horizon, we cannot possibly see the deleting transaction */
    else if (TransactionIdFollowsOrEquals(xmax, snapshot->xmax))
        return true;
    /* xmax is between [xmin, xmax), check known committed array */
    else if (TransactionIdInArray(xmax, snapshot->xip, snapshot->xcnt))
        return false;
    /* xmax is between [xmin, xmax), but known not to have committed yet */
    else
        return true;
}

References Assert(), SnapshotData::curcid, HEAP_XMAX_COMMITTED, HEAP_XMAX_INVALID, HEAP_XMAX_IS_LOCKED_ONLY(), HEAP_XMAX_IS_MULTI, HeapTupleGetUpdateXid(), HeapTupleHeaderGetRawCommandId(), HeapTupleHeaderGetRawXmax(), HeapTupleHeaderGetXmin(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminInvalid(), HistoricSnapshotGetTupleCids(), InvalidCommandId, InvalidOid, ItemPointerIsValid(), ResolveCminCmaxDuringDecoding(), SnapshotData::subxcnt, SnapshotData::subxip, HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, HeapTupleData::t_tableOid, TransactionIdDidCommit(), TransactionIdFollowsOrEquals(), TransactionIdInArray(), TransactionIdPrecedes(), SnapshotData::xcnt, SnapshotData::xip, SnapshotData::xmax, and SnapshotData::xmin.

Referenced by HeapTupleSatisfiesVisibility().

◆ HeapTupleSatisfiesMVCC()

static bool HeapTupleSatisfiesMVCC	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

static

Definition at line 861 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
 
    /*
     * Assert that the caller has registered the snapshot.  This function
     * doesn't care about the registration as such, but in general you
     * shouldn't try to use a snapshot without registration because it might
     * get invalidated while it's still in use, and this is a convenient place
     * to check for that.
     */
    Assert(snapshot->regd_count > 0 || snapshot->active_count > 0);
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
 
    if (!HeapTupleHeaderXminCommitted(tuple))
    {
        if (HeapTupleHeaderXminInvalid(tuple))
            return false;
 
        if (!HeapTupleCleanMoved(tuple, buffer))
            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 (XidInMVCCSnapshot(HeapTupleHeaderGetRawXmin(tuple), snapshot))
            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;
        }
    }
    else
    {
        /* xmin is committed, but maybe not according to our snapshot */
        if (!HeapTupleHeaderXminFrozen(tuple) &&
            XidInMVCCSnapshot(HeapTupleHeaderGetRawXmin(tuple), snapshot))
            return false;       /* treat as still in progress */
    }
 
    /* by here, the inserting transaction has committed */
 
    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 (XidInMVCCSnapshot(xmax, snapshot))
            return true;
        if (TransactionIdDidCommit(xmax))
            return false;       /* updating transaction committed */
        /* 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 (XidInMVCCSnapshot(HeapTupleHeaderGetRawXmax(tuple), snapshot))
            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));
    }
    else
    {
        /* xmax is committed, but maybe not according to our snapshot */
        if (XidInMVCCSnapshot(HeapTupleHeaderGetRawXmax(tuple), snapshot))
            return true;        /* treat as still in progress */
    }
 
    /* xmax transaction committed */
 
    return false;
}

References SnapshotData::active_count, Assert(), SnapshotData::curcid, HEAP_XMAX_COMMITTED, HEAP_XMAX_INVALID, HEAP_XMAX_IS_LOCKED_ONLY(), HEAP_XMAX_IS_MULTI, HEAP_XMIN_COMMITTED, HEAP_XMIN_INVALID, HeapTupleCleanMoved(), HeapTupleGetUpdateXid(), HeapTupleHeaderGetCmax(), HeapTupleHeaderGetCmin(), HeapTupleHeaderGetRawXmax(), HeapTupleHeaderGetRawXmin(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminFrozen(), HeapTupleHeaderXminInvalid(), InvalidOid, InvalidTransactionId, ItemPointerIsValid(), SnapshotData::regd_count, SetHintBits(), HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, HeapTupleData::t_tableOid, TransactionIdDidCommit(), TransactionIdIsCurrentTransactionId(), TransactionIdIsValid, and XidInMVCCSnapshot().

Referenced by HeapTupleSatisfiesVisibility().

◆ HeapTupleSatisfiesNonVacuumable()

static bool HeapTupleSatisfiesNonVacuumable	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

static

Definition at line 1267 of file heapam_visibility.c.

{
    TransactionId dead_after = InvalidTransactionId;
    HTSV_Result res;
 
    res = HeapTupleSatisfiesVacuumHorizon(htup, buffer, &dead_after);
 
    if (res == HEAPTUPLE_RECENTLY_DEAD)
    {
        Assert(TransactionIdIsValid(dead_after));
 
        if (GlobalVisTestIsRemovableXid(snapshot->vistest, dead_after))
            res = HEAPTUPLE_DEAD;
    }
    else
        Assert(!TransactionIdIsValid(dead_after));
 
    return res != HEAPTUPLE_DEAD;
}

References Assert(), GlobalVisTestIsRemovableXid(), HEAPTUPLE_DEAD, HEAPTUPLE_RECENTLY_DEAD, HeapTupleSatisfiesVacuumHorizon(), InvalidTransactionId, TransactionIdIsValid, and SnapshotData::vistest.

Referenced by HeapTupleSatisfiesVisibility().

◆ HeapTupleSatisfiesSelf()

static bool HeapTupleSatisfiesSelf	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

static

Definition at line 219 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
 
    if (!HeapTupleHeaderXminCommitted(tuple))
    {
        if (HeapTupleHeaderXminInvalid(tuple))
            return false;
 
        if (!HeapTupleCleanMoved(tuple, buffer))
            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)))
            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 */
 
    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))
            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)))
        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;
}

References Assert(), HEAP_XMAX_COMMITTED, HEAP_XMAX_INVALID, HEAP_XMAX_IS_LOCKED_ONLY(), HEAP_XMAX_IS_MULTI, HEAP_XMIN_COMMITTED, HEAP_XMIN_INVALID, HeapTupleCleanMoved(), HeapTupleGetUpdateXid(), HeapTupleHeaderGetRawXmax(), HeapTupleHeaderGetRawXmin(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminInvalid(), InvalidOid, InvalidTransactionId, ItemPointerIsValid(), SetHintBits(), HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, HeapTupleData::t_tableOid, TransactionIdDidCommit(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), and TransactionIdIsValid.

Referenced by HeapTupleSatisfiesVisibility().

◆ HeapTupleSatisfiesToast()

static bool HeapTupleSatisfiesToast	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

static

Definition at line 374 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
 
    if (!HeapTupleHeaderXminCommitted(tuple))
    {
        if (HeapTupleHeaderXminInvalid(tuple))
            return false;
 
        if (!HeapTupleCleanMoved(tuple, buffer))
            return false;
 
        /*
         * An invalid Xmin can be left behind by a speculative insertion that
         * is canceled by super-deleting the tuple.  This also applies to
         * TOAST tuples created during speculative insertion.
         */
        else if (!TransactionIdIsValid(HeapTupleHeaderGetXmin(tuple)))
            return false;
    }
 
    /* otherwise assume the tuple is valid for TOAST. */
    return true;
}

References Assert(), HeapTupleCleanMoved(), HeapTupleHeaderGetXmin(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminInvalid(), InvalidOid, ItemPointerIsValid(), HeapTupleData::t_data, HeapTupleData::t_self, HeapTupleData::t_tableOid, and TransactionIdIsValid.

Referenced by HeapTupleSatisfiesVisibility().

◆ HeapTupleSatisfiesUpdate()

TM_Result HeapTupleSatisfiesUpdate	(	HeapTuple	htup,
		CommandId	curcid,
		Buffer	buffer
	)

Definition at line 433 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
 
    if (!HeapTupleHeaderXminCommitted(tuple))
    {
        if (HeapTupleHeaderXminInvalid(tuple))
            return TM_Invisible;
 
        else if (!HeapTupleCleanMoved(tuple, buffer))
            return TM_Invisible;
        else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmin(tuple)))
        {
            if (HeapTupleHeaderGetCmin(tuple) >= curcid)
                return TM_Invisible;    /* inserted after scan started */
 
            if (tuple->t_infomask & HEAP_XMAX_INVALID)  /* xid invalid */
                return TM_Ok;
 
            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 (MultiXactIdIsRunning(xmax, true))
                        return TM_BeingModified;
                    else
                        return TM_Ok;
                }
 
                /*
                 * If the locker is gone, then there is nothing of interest
                 * left in this Xmax; otherwise, report the tuple as
                 * locked/updated.
                 */
                if (!TransactionIdIsInProgress(xmax))
                    return TM_Ok;
                return TM_BeingModified;
            }
 
            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));
 
                /* deleting subtransaction must have aborted */
                if (!TransactionIdIsCurrentTransactionId(xmax))
                {
                    if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple),
                                             false))
                        return TM_BeingModified;
                    return TM_Ok;
                }
                else
                {
                    if (HeapTupleHeaderGetCmax(tuple) >= curcid)
                        return TM_SelfModified; /* updated after scan started */
                    else
                        return TM_Invisible;    /* updated before scan started */
                }
            }
 
            if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
            {
                /* deleting subtransaction must have aborted */
                SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
                            InvalidTransactionId);
                return TM_Ok;
            }
 
            if (HeapTupleHeaderGetCmax(tuple) >= curcid)
                return TM_SelfModified; /* updated after scan started */
            else
                return TM_Invisible;    /* updated before scan started */
        }
        else if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmin(tuple)))
            return TM_Invisible;
        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 TM_Invisible;
        }
    }
 
    /* by here, the inserting transaction has committed */
 
    if (tuple->t_infomask & HEAP_XMAX_INVALID)  /* xid invalid or aborted */
        return TM_Ok;
 
    if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
    {
        if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
            return TM_Ok;
        if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
            return TM_Updated;  /* updated by other */
        else
            return TM_Deleted;  /* deleted by other */
    }
 
    if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
    {
        TransactionId xmax;
 
        if (HEAP_LOCKED_UPGRADED(tuple->t_infomask))
            return TM_Ok;
 
        if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
        {
            if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), true))
                return TM_BeingModified;
 
            SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
            return TM_Ok;
        }
 
        xmax = HeapTupleGetUpdateXid(tuple);
        if (!TransactionIdIsValid(xmax))
        {
            if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
                return TM_BeingModified;
        }
 
        /* not LOCKED_ONLY, so it has to have an xmax */
        Assert(TransactionIdIsValid(xmax));
 
        if (TransactionIdIsCurrentTransactionId(xmax))
        {
            if (HeapTupleHeaderGetCmax(tuple) >= curcid)
                return TM_SelfModified; /* updated after scan started */
            else
                return TM_Invisible;    /* updated before scan started */
        }
 
        if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
            return TM_BeingModified;
 
        if (TransactionIdDidCommit(xmax))
        {
            if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
                return TM_Updated;
            else
                return TM_Deleted;
        }
 
        /*
         * By here, the update in the Xmax is either aborted or crashed, but
         * what about the other members?
         */
 
        if (!MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
        {
            /*
             * 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 TM_Ok;
        }
        else
        {
            /* There are lockers running */
            return TM_BeingModified;
        }
    }
 
    if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
    {
        if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
            return TM_BeingModified;
        if (HeapTupleHeaderGetCmax(tuple) >= curcid)
            return TM_SelfModified; /* updated after scan started */
        else
            return TM_Invisible;    /* updated before scan started */
    }
 
    if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
        return TM_BeingModified;
 
    if (!TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
    {
        /* it must have aborted or crashed */
        SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
                    InvalidTransactionId);
        return TM_Ok;
    }
 
    /* xmax transaction committed */
 
    if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
    {
        SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
                    InvalidTransactionId);
        return TM_Ok;
    }
 
    SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
                HeapTupleHeaderGetRawXmax(tuple));
    if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
        return TM_Updated;      /* updated by other */
    else
        return TM_Deleted;      /* deleted by other */
}

References Assert(), HEAP_LOCKED_UPGRADED(), HEAP_XMAX_COMMITTED, HEAP_XMAX_INVALID, HEAP_XMAX_IS_LOCKED_ONLY(), HEAP_XMAX_IS_MULTI, HEAP_XMIN_COMMITTED, HEAP_XMIN_INVALID, HeapTupleCleanMoved(), HeapTupleGetUpdateXid(), HeapTupleHeaderGetCmax(), HeapTupleHeaderGetCmin(), HeapTupleHeaderGetRawXmax(), HeapTupleHeaderGetRawXmin(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminInvalid(), InvalidOid, InvalidTransactionId, ItemPointerEquals(), ItemPointerIsValid(), MultiXactIdIsRunning(), SetHintBits(), HeapTupleHeaderData::t_ctid, HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, HeapTupleData::t_tableOid, TM_BeingModified, TM_Deleted, TM_Invisible, TM_Ok, TM_SelfModified, TM_Updated, TransactionIdDidCommit(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), and TransactionIdIsValid.

Referenced by heap_delete(), heap_inplace_lock(), heap_lock_tuple(), heap_update(), and pgrowlocks().

◆ HeapTupleSatisfiesVacuum()

HTSV_Result HeapTupleSatisfiesVacuum	(	HeapTuple	htup,
		TransactionId	OldestXmin,
		Buffer	buffer
	)

Definition at line 1035 of file heapam_visibility.c.

{
    TransactionId dead_after = InvalidTransactionId;
    HTSV_Result res;
 
    res = HeapTupleSatisfiesVacuumHorizon(htup, buffer, &dead_after);
 
    if (res == HEAPTUPLE_RECENTLY_DEAD)
    {
        Assert(TransactionIdIsValid(dead_after));
 
        if (TransactionIdPrecedes(dead_after, OldestXmin))
            res = HEAPTUPLE_DEAD;
    }
    else
        Assert(!TransactionIdIsValid(dead_after));
 
    return res;
}

References Assert(), HEAPTUPLE_DEAD, HEAPTUPLE_RECENTLY_DEAD, HeapTupleSatisfiesVacuumHorizon(), InvalidTransactionId, TransactionIdIsValid, and TransactionIdPrecedes().

Referenced by heap_page_would_be_all_visible(), heapam_index_build_range_scan(), heapam_relation_copy_for_cluster(), heapam_scan_analyze_next_tuple(), HeapCheckForSerializableConflictOut(), lazy_scan_noprune(), statapprox_heap(), tuple_all_visible(), and update_most_recent_deletion_info().

◆ HeapTupleSatisfiesVacuumHorizon()

HTSV_Result HeapTupleSatisfiesVacuumHorizon	(	HeapTuple	htup,
		Buffer	buffer,
		TransactionId *	dead_after
	)

Definition at line 1069 of file heapam_visibility.c.

{
    HeapTupleHeader tuple = htup->t_data;
 
    Assert(ItemPointerIsValid(&htup->t_self));
    Assert(htup->t_tableOid != InvalidOid);
    Assert(dead_after != NULL);
 
    *dead_after = InvalidTransactionId;
 
    /*
     * 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;
        else if (!HeapTupleCleanMoved(tuple, buffer))
            return HEAPTUPLE_DEAD;
        else if (TransactionIdIsCurrentTransactionId(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 */
            if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(tuple)))
                return HEAPTUPLE_DELETE_IN_PROGRESS;
            /* deleting subtransaction must have aborted */
            return HEAPTUPLE_INSERT_IN_PROGRESS;
        }
        else if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmin(tuple)))
        {
            /*
             * It'd be possible to discern between INSERT/DELETE in progress
             * here by looking at xmax - but that doesn't seem beneficial for
             * the majority of callers and even detrimental for some. We'd
             * rather have callers look at/wait for xmin than xmax. It's
             * always correct to return INSERT_IN_PROGRESS because that's
             * what's happening from the view of other backends.
             */
            return HEAPTUPLE_INSERT_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.
         */
        if (!(tuple->t_infomask & HEAP_XMAX_COMMITTED))
        {
            if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
            {
                /*
                 * If it's a pre-pg_upgrade tuple, the multixact cannot
                 * possibly be running; otherwise have to check.
                 */
                if (!HEAP_LOCKED_UPGRADED(tuple->t_infomask) &&
                    MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple),
                                         true))
                    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 = HeapTupleGetUpdateXid(tuple);
 
        /* already checked above */
        Assert(!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask));
 
        /* 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))
        {
            /*
             * The multixact might still be running due to lockers.  Need to
             * allow for pruning if below the xid horizon regardless --
             * otherwise we could end up with a tuple where the updater has to
             * be removed due to the horizon, but is not pruned away.  It's
             * not a problem to prune that tuple, because any remaining
             * lockers will also be present in newer tuple versions.
             */
            *dead_after = xmax;
            return HEAPTUPLE_RECENTLY_DEAD;
        }
        else if (!MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
        {
            /*
             * Not in Progress, Not Committed, so either Aborted or crashed.
             * Mark the Xmax as invalid.
             */
            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, allow caller to check if it was recent enough that
     * some open transactions could still see the tuple.
     */
    *dead_after = HeapTupleHeaderGetRawXmax(tuple);
    return HEAPTUPLE_RECENTLY_DEAD;
}

References Assert(), HEAP_LOCKED_UPGRADED(), HEAP_XMAX_COMMITTED, HEAP_XMAX_INVALID, HEAP_XMAX_IS_LOCKED_ONLY(), HEAP_XMAX_IS_MULTI, HEAP_XMIN_COMMITTED, HEAP_XMIN_INVALID, HEAPTUPLE_DEAD, HEAPTUPLE_DELETE_IN_PROGRESS, HEAPTUPLE_INSERT_IN_PROGRESS, HEAPTUPLE_LIVE, HEAPTUPLE_RECENTLY_DEAD, HeapTupleCleanMoved(), HeapTupleGetUpdateXid(), HeapTupleHeaderGetRawXmax(), HeapTupleHeaderGetRawXmin(), HeapTupleHeaderGetUpdateXid(), HeapTupleHeaderIsOnlyLocked(), HeapTupleHeaderXminCommitted(), HeapTupleHeaderXminInvalid(), InvalidOid, InvalidTransactionId, ItemPointerIsValid(), MultiXactIdIsRunning(), SetHintBits(), HeapTupleData::t_data, HeapTupleHeaderData::t_infomask, HeapTupleData::t_self, HeapTupleData::t_tableOid, TransactionIdDidCommit(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), and TransactionIdIsValid.

Referenced by heap_prune_satisfies_vacuum(), HeapTupleSatisfiesNonVacuumable(), and HeapTupleSatisfiesVacuum().

◆ HeapTupleSatisfiesVisibility()

bool HeapTupleSatisfiesVisibility	(	HeapTuple	htup,
		Snapshot	snapshot,
		Buffer	buffer
	)

Definition at line 1605 of file heapam_visibility.c.

{
    switch (snapshot->snapshot_type)
    {
        case SNAPSHOT_MVCC:
            return HeapTupleSatisfiesMVCC(htup, snapshot, buffer);
        case SNAPSHOT_SELF:
            return HeapTupleSatisfiesSelf(htup, snapshot, buffer);
        case SNAPSHOT_ANY:
            return HeapTupleSatisfiesAny(htup, snapshot, buffer);
        case SNAPSHOT_TOAST:
            return HeapTupleSatisfiesToast(htup, snapshot, buffer);
        case SNAPSHOT_DIRTY:
            return HeapTupleSatisfiesDirty(htup, snapshot, buffer);
        case SNAPSHOT_HISTORIC_MVCC:
            return HeapTupleSatisfiesHistoricMVCC(htup, snapshot, buffer);
        case SNAPSHOT_NON_VACUUMABLE:
            return HeapTupleSatisfiesNonVacuumable(htup, snapshot, buffer);
    }
 
    return false;               /* keep compiler quiet */
}

References HeapTupleSatisfiesAny(), HeapTupleSatisfiesDirty(), HeapTupleSatisfiesHistoricMVCC(), HeapTupleSatisfiesMVCC(), HeapTupleSatisfiesNonVacuumable(), HeapTupleSatisfiesSelf(), HeapTupleSatisfiesToast(), SNAPSHOT_ANY, SNAPSHOT_DIRTY, SNAPSHOT_HISTORIC_MVCC, SNAPSHOT_MVCC, SNAPSHOT_NON_VACUUMABLE, SNAPSHOT_SELF, SNAPSHOT_TOAST, and SnapshotData::snapshot_type.

Referenced by BitmapHeapScanNextBlock(), heap_delete(), heap_fetch(), heap_get_latest_tid(), heap_hot_search_buffer(), heap_update(), heapam_tuple_satisfies_snapshot(), heapgettup(), page_collect_tuples(), pgstat_heap(), SampleHeapTupleVisible(), and ScanSourceDatabasePgClassPage().

◆ HeapTupleSetHintBits()

void HeapTupleSetHintBits	(	HeapTupleHeader	tuple,
		Buffer	buffer,
		uint16	infomask,
		TransactionId	xid
	)

Definition at line 141 of file heapam_visibility.c.

{
    SetHintBits(tuple, buffer, infomask, xid);
}

References SetHintBits().

Referenced by UpdateXmaxHintBits().

◆ SetHintBits()

static void SetHintBits	(	HeapTupleHeader	tuple,
		Buffer	buffer,
		uint16	infomask,
		TransactionId	xid
	)

inlinestatic

Definition at line 114 of file heapam_visibility.c.

{
    if (TransactionIdIsValid(xid))
    {
        /* NB: xid must be known committed here! */
        XLogRecPtr  commitLSN = TransactionIdGetCommitLSN(xid);
 
        if (BufferIsPermanent(buffer) && XLogNeedsFlush(commitLSN) &&
            BufferGetLSNAtomic(buffer) < commitLSN)
        {
            /* not flushed and no LSN interlock, so don't set hint */
            return;
        }
    }
 
    tuple->t_infomask |= infomask;
    MarkBufferDirtyHint(buffer, true);
}

References BufferGetLSNAtomic(), BufferIsPermanent(), MarkBufferDirtyHint(), HeapTupleHeaderData::t_infomask, TransactionIdGetCommitLSN(), TransactionIdIsValid, and XLogNeedsFlush().

Referenced by HeapTupleCleanMoved(), HeapTupleSatisfiesDirty(), HeapTupleSatisfiesMVCC(), HeapTupleSatisfiesSelf(), HeapTupleSatisfiesUpdate(), HeapTupleSatisfiesVacuumHorizon(), and HeapTupleSetHintBits().

◆ TransactionIdInArray()

static bool TransactionIdInArray	(	TransactionId	xid,
		TransactionId *	xip,
		Size	num
	)

static

Definition at line 1404 of file heapam_visibility.c.

{
    return num > 0 &&
        bsearch(&xid, xip, num, sizeof(TransactionId), xidComparator) != NULL;
}

References xidComparator().

Referenced by HeapTupleSatisfiesHistoricMVCC().

Functions

Function Documentation

◆ HeapTupleCleanMoved()

◆ HeapTupleHeaderIsOnlyLocked()

◆ HeapTupleIsSurelyDead()

◆ HeapTupleSatisfiesAny()

◆ HeapTupleSatisfiesDirty()

◆ HeapTupleSatisfiesHistoricMVCC()

◆ HeapTupleSatisfiesMVCC()

◆ HeapTupleSatisfiesNonVacuumable()

◆ HeapTupleSatisfiesSelf()

◆ HeapTupleSatisfiesToast()

◆ HeapTupleSatisfiesUpdate()

◆ HeapTupleSatisfiesVacuum()

◆ HeapTupleSatisfiesVacuumHorizon()

◆ HeapTupleSatisfiesVisibility()

◆ HeapTupleSetHintBits()

◆ SetHintBits()

◆ TransactionIdInArray()